EFFECTS version information 1

Table of Contents

Version 12 release history 2

Version 11 release history 9
Version 10 release history 20
Version 9 release history 30
Version 8 release history 37
Version 7 release history 40

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EFFECTS version information 2
Version 12 release history

Version 12 release history

EFFECTS 12.5.1 (March 2025) Version Info

· Chemical Editor bug fix: Version 12.5.0 contained an issue causing an unhandled exception in the
chemical editor, when a temperature-dependent chemical property was selected. This patch, version
12.5.1, solves this issue.

EFFECTS 12.5.0 (March 2025) Version Info

New features and model extensions:

· New export tool in EFFECTS and RISKCURVES: A new report generation tool allows users to export all
modelling results directly to a Word document. This option can be accessed via the menu
"File..Export..Generate project report". This streamlined reporting feature provides a comprehensive
summary of all input parameters and results for all models or scenarios in a project, ensuring quick and
professional reporting.
· Liquefied Gas from Long Pipeline model: This model has been extended to include the prediction of
behaviour after reaching the triple point temperature, improving accuracy for CO2 pipeline releases.
Previous versions could not account for solidification effects, as the calculation would stop while the
pressure in the pipeline was still high enough to blow out a solid/vapour mixture. Users will notice that
the representative release rates for CO2 pipelines may have changed, as the additional outflow
influences the averaged representative release rate and its conditions. The theoretical background and
the updated validation of the Liquefied Gas from Long Pipeline model is provided in a validation report,
available on our documents-portal.
· Combined LOC Scenarios for Long Pipelines: The Liquefied Gas and Gas Release from Long Pipeline
models are now available in dedicated combined loss of containments (LOC) scenario models. This
integration allows users evaluate all potential outcomes of a pressurised long pipeline release, including
direct ignition, delayed ignition and toxic exposure.
· Dispersion - Flammable Cloud models: The flammable cloud dispersion model now includes a "Cloud
passage time versus distance" graph. This new result predicts how long the LFL concentration will be
present at a specific distance (at the cloud centreline). This cloud passage time is relevant to assess
ignition probability based on ignition sources.
· User interface and help enhancements: The Help menu now includes a direct link to downloadable
example projects available from our website, for hands-on learning.
· Dispersion model documentation: The dispersion model has been validated against a wide range of
ammonia experiments. The findings are documented in the updated version of the Dispersion Validation
Report, available on our documents-portal.
· Jet Fire model documentation: A Jet Fire Validation Report is now available on our documents-portal,
providing detailed insights into the model’s performance and validation process.
· Knowledge Base: Users can access the Gexcon Knowledge base (https://knowledge.gexcon.com/) for
valuable guides and best practises on using EFFECTS and RISKCURVES and the latest functionality
effectively.

Bug fix es and performance improvements:

Thanks to valuable feedback from our clients, this version resolves bugs and enhances the overall software
experience. These improvements are designed to increase modelling accuracy and usability across various
scenarios.

· Chemical database: Resolved issues with storing user-defined materials in projects. Users can now load
and recalculate a project with user-defined chemical information on a machine that does not have the
user-defined database attached. It now also enables users to apply "user defined" substances in
mixtures. Additionally, extrapolation beyond valid temperature ranges is now supported for cached
chemicals. This extrapolation is now fully enabled for properties that apply multiple temperature ranges
(using a dedicated formulation for every range).
· Liquefied Gas Spray Release model: Statistical Spray method: The statistical spray method now
resolves inconsistencies leading to overly high liquid fractions, with a correction made for discharge

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EFFECTS version information 3
Version 12 release history

coefficient use. The model now also allows solid in the outflow and adjusts adiabatic flash for solids
present in outflow, which can now occur in case of CO2 pipeline releases.
· Gas Release from Long Pipeline model: The inlet flow-rate, which users may apply as an upstream inlet
feed, is no longer being limited. Previous version would reject flow rates that would lead to flow velocities
higher than 30 m/s, this precondition has been skipped based on user requests.
· LOC scenarios: A potential error when switching to "fixed outflow" due to missing hole diameter result
has been fixed.
· Dispersion models, gaseous jet releases: Inconsistent release conditions (pressure, hole size, flow-rate)
now trigger an appropriate warnings, ensuring users are informed of unrealistic results due to
inconsistent input. Additionally, potential errors arising from such inconsistent inputs are now handled
appropriately to improve reliability.
· Dispersion models, gaseous jet releases: Graph resolution for initial jet expansion phases has been
improved, eliminating data jumps from large step sizes.
· Jet Fire model: When linked to a two phase release model, potential rain-out of droplets is no longer
extracted from the source rate, ensuring direct ignition scenarios reflect full mass flow involvement in the
jet fire event.
· Jet Fire model: The "1% lethality" contour is now displayed as "1% lethality heat radiation", providing
more accurate data for flame contact prediction (because the projected direct flame contact footprint
might even lead to larger distances).
· Jet Fire model: Buried pipeline releases (with a negative release height) now default to a vertical outflow
direction, reflecting real-world blowout behaviour.
· Vapour Cloud Explosion model: The reported results for "at Xd" (which is the reporting / receiver
distance) are now corrected for potential offset between release and explosion centre. This implies that
Xd for explosion can now be considered distance from release rather than distance from explosion
centre.

EFFECTS 12.4.0 (September 2024) Version Info

· Li-Ion battery storage thermal runaway model: A completely new source rate prediction model has been
added, providing estimations of (toxic) gas production due to thermal runaway occurring in Li-Ion battery
storage systems.This empirical model relies on recently published compiled data from 60 different
experiments, and predicts HF, CO, HCl, HCN and NO2 production, using inputs on battery capacity,
number of elements (within a cell/module or complete system), and battery chemistry. The typical
cathode types supported by the model are Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt
(NMC), which are currently the most commonly battery types applied. It is advised to apply the
calculated source rate in a "Neutral Gas Toxic Dose" calculation, as a user defined window source using
the width and height of the battery storage system dimensions to include a lee-wake situation. A
detailed description of the theory behind the model, including a elaborated example calculation, is
provided in a theoretical background document available on our documents portal.
· Modelling of buried pipelines (within Liquefied gas from long pipeline model): The liquefied gas from long
pipeline model now supports releases from buried pipelines. These releases from buried pipelines will
form a crater, for which the dimensions and effective outflow area will be calculated. Within the crater, an
additional dilution with air is predicted which, together with reduced momentum in vertical direction, will
influence following dispersion behaviour. The theoretical background and validation of this crater
modelling is provided in and additional document, available on our documents-portal.
· Liquefied gas from long pipeline model: When using the "Statistical spray" approach to determine droplet
rain-out, which method is specifically intended for CO2 releases, the calculation now supports using
higher accuracy by selecting another "Sample size resolution" value.
· Liquefied gas from long pipeline model: The reported "initial mass in the pipeline" when using "double
sided outflow" is corrected, because it was previously based on the contents of half the pipeline length.
This inconstancy would also lead to a wrong "representative outflow duration".This bug has been fixed in
version 12.4. and will lead to twice the previously reported outflow duration and initial mass for a typical
double sided outflow calculation. Furthermore, when performing a double sided outflow calculation for
CO2 using the new Webber approach, the outflow calculation could stop because the triple point was

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EFFECTS version information 4
Version 12 release history

reached, and skip the flow-rate multiplication by 2 related to a double sided outflow. This potential issue
has also been fixed.
· Dispersion model: As a follow up of the crater outflow, the dispersion model now supports a dedicated
“release from crater” source type. This source type will use the calculated effective crater outflow area,
as well as the dilution factor, expressed by the "mass fraction chemical" leaving the crater. The model
has been validated for CO2 releases from a crater, where the ratio between crater exit velocity and wind
speed together with a Richardson number will determine whether the resulting cloud behaves like a
“blanket”, which also shows upwind spreading due to heavy gas behaviour, or as a vertical jet. For non
CO2 releases from a crater, the crater release will apply a "vertical jet" source, with reduced velocity and
including predicted dilution in the crater. An updated version of the dispersion validation report to include
this new crater functionality is available on our documents-portal.
· Dispersion model: When using the vertical jet source with a pure gaseous (no liquid droplets) situation,
the concentration versus time graph could show an unrealistic decrease at times lower than the release
duration. This time scaling issue has been fixed and might influence dose calculation results for gaseous
vertical jet situations. Furthermore, the modelling of vertical jet releases lighter than air has been
significantly improved, taking more physics in the entrainment calculations into account. The new model
has been extensively validated; the effect distances might be reduced compared with previous versions.
An updated version of the dispersion validation report to include the improvements to the vertical jet
source is available on our documents-portal.
· Dispersion model: For horizontal jet releases at significant height, the switching from "turbulent jet"
expansion regime to wind driven dispersion could lead to an inconsistent concentration behaviour due to
the high local wind velocity at that height. This transition from jet towards dispersion is now taking the
actual wind speed at release height into account.
· Dispersion model: Potential error messages resulting from missing liquid properties for a component
within a mixture are now being avoided when having pure gas situations.
· Jet fire model damage calculation: The jet fire model now includes a new parameter "Duration of the
release" which can potentially limit the "heat exposure duration" which is applied to calculate heat
dosage. This modification allows complying with (Norwegian) regulatory requirements that don't limit
radiation damage with a heat exposure duration. Whenever the duration of the fire is shorter than the
"heat exposure duration" as defined in "Vulnerability", this fire duration will now determine the reported
dosage and associated first degree, second degree and third degree percentages burns results. Jet fire
calculations done with previous versions may now require an additional input, unless the jet fire is
preceded by a release calculation, where the new jet fire input will automatically link to calculated
"Representative outflow duration".
· Jet fire model: When connecting a jet fire model to a buried long pipeline calculation, the negative height
of release (which relates to the depth of the pipeline) will automatically force the jet fire to be grounded:
the jet fire will not have any lift -off due to reduced vertical velocity. This behaviour was already present in
previous versions, but scarcely applied by users.
· Chemical database: An inconsistency in the applied mixing rule for liquid density of a mixture, as shown
in the "Mass and volume calculator" and in the "liquid density" graph of the Chemical Editor has been
fixed. This issue could lead to non-accurate liquid contents calculations for mixtures, specifically when
the mixture contained components with large differences in liquid density.
· Gas Instantaneous Release model: The calculation of the expansion has been improved, now using non
ideal gas relations, leading to more accurate expanded temperature and thus expanded density results.
· Gas Release model: the reporting of "expanded density" has been removed from the output, because the
model should report associated exit conditions. Expansion of the calculated outflow is being dealt with in
the subsequent jet dispersion phase (or jet fire) which applies conditions in the exit plane.
· Liquefied gas release models: A minor inconsistency in the calculation of the liquid fraction after
flashing and rain-out, occurring when the pipe exit already contained a significant vapour fraction, was
corrected. This might lead to a potential higher liquid fraction after flashing for those specific situations.
· Toxic combustion products model: The input definition of this model has been more intuitive. Instead of
choosing a phase (Liquid / Solid / Solid mixture from database) it now asks for "Type of fire" which can
be a "Pool fire" or "Warehouse fire". For warehouse fire, the source composition can be defined by
referring to a mixture defined in the database, or by defining an average molecular formula. For a pool
fire, a straightforward chemical can be selected. Phase type choices, as made in previous versions, will
automatically be translated into the corresponding fire type of the new definition.

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EFFECTS version information 5
Version 12 release history

EFFECTS 12.3.0 (April 2024) Version Info

· Liquefied gas from long pipeline model: A new "long pipeline" modelling approach for PLG (Pressurised
Liquefied Gas) has been added. This new methodology based on "Webber's" model also allows
calculation of smaller leaks (not necessary "full bore" ruptures), supports accurate CO2 (PLG phase)
releases, and is the new preferred / default model. The former "Morrow" model is still supported, but it is
strongly advised to recalculate the scenario using the new Webber approach. This is the preferred model
because the results of the Morrow model are highly influenced by the user input "Sound speed in liquid
phase", while this parameter is no longer relevant within the new Webber modelling approach.
· Liquid release model: The reported exit pressure, which was previously referred to as the pressure at the
vessel exit, now refers to pipe exit, and incorporates friction losses in the pipe.
· Unified release model: An issue with user defined discharge coefficient not loaded correctly has been
solved.
· Neutral gas dispersion: When applying the "release from user defined window", the height of the release
will automatically be minimised to the centre of the window. This influences the concentration
distribution over the height of this outflow, now assuming the plume is symmetric around the centre of
the outflow window.
· Flammable cloud dispersion model: The reported flammable mass and area or volume of the cloud will
no longer be rounded off to whole digits. When applying small release rates, the model now correctly
reports the occurrence of flammable contents, even if it is below 1 kg or 1 m2 / m3.
· User interface: A problem with a hidden vessel pressure parameter in gas release after switching back
from 10 minutes outflow has been fixed.
· User interface: The display of tile server background maps as "grey-scale" has been improved.
· Project file format: The storage of "user defined chemicals" inside the project file has been adapted,
improving the transferability of the project with other users. This modification implies that version 12.3
project files that include user chemicals are not downwards compatible with previous versions.

EFFECTS 12.2.0 (October 2023) Version Info

· Dispersion model: In EFFECTS, by default the “wind speed reference height” is 10m which describes the
height at which the provided wind speed is measured. This is because meteorological data is by default
provided at this measurement height.
When performing validation work and comparing simulations against experimental data, the wind speed
may need to be defined at a different reference height. That is the reason why an additional (expert) input
has been incorporated in the dispersion model. This input parameter was available within the algorithm
internally but wasn’t enabled in EFFECTS’ commercial version. This new parameter now allows the
specification of wind speed at a different measurement height than the default of 10 m. Nevertheless, we
strongly advise users to apply the default 10 m reference height for calculations, referring to standard
meteorological data.
· Dispersion model: During the verification procedure of the EFFECTS v12 Dispersion model, an
inconsistency in the used wind velocity profiles was discovered. The issue was that the same wind
profile could not be reproduced when entering corresponding wind velocities at different heights. A
modification of the given Pasquil stability class (or Monin Obukhov length) based on the reference input
(wind speed and reference height of the wind speed) might have led to slightly different wind velocity
profiles and dispersion behaviour. This inconsistent behaviour has been fixed, potentially leading to a
different wind velocity vs height behaviour compared to the previous version. Calculated concentrations
may be different for this software release, in particular for stable atmospheric classes. Small differences
have been observed for Pasquill stability classes A-C, neglectable difference has been observed for
Pasquill stability class D, and noticeable differences have been observed for Pasquill stability classes E-
F. The modifications in this software release result into a better agreement with experimental data
ranging from heavy gas releases to passive dispersion.
· Dispersion model: The parameters "offset X direction" and "offset Y direction" have been removed,
because potential offset due to the jet region is already included in the results. The application of an
offset of 1 m in x direction, when using a vertical jets, has been skipped.

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EFFECTS version information 6
Version 12 release history

· Dispersion model: jet release mode: If the concentration of interest (LFL for flammable, and LC1% for
toxics) did not reach outside the jet expansion region, this contour might be hidden, while its flammable
mass and toxicity footprints were correctly reported. This behaviour has been corrected. Furthermore,
contours which reflect "reporting height Zd" will no longer be extended with the jet contour if Zd is not at
the centre of the jet.
· Neutral gas dispersion model: jet release mode The side view contour presented by the neutral
dispersion model could be influenced by preceding jet expansion phase, leading to an inconsistent initial
offset. This behaviour has been fixed.
· Neutral gas dispersion Toxic Dose: The model now allows plotting of contours for user defined dosage
levels below 10-12 s*(kg/m3)^n, which were previously skipped and considered irrelevant.
· Liquefied Gas Bottom Discharge model: This model now integrates the "Liquefied Gas Vapour Venting"
to calculate top vent situations as well as the "Liquefied Gas Spray Release" model to calculate the
flashing phenomenon for semi-continuous releases. This "Bottom Discharge" model has been renamed
to "Liquefied gas release" model and now automatically switches to a vapour vent if the location of the
hole is above liquid level. The integration of the spray release calculation avoids required linking of this
model to obtain information about liquid rain-out, aerosol liquid fraction and expanded diameter. Because
these models are now integrated within the liquefied gas release, the spray and vapour vent models are
no longer available as separate dedicated release models. For a "fixed flowrate" calculation (aimed at
finding the exit pressure to obtain a specific flow rate), the user can still select "fixed flow rate vapour
phase" to assume a pure gaseous outflow from a two phase vessel, while the "fixed flow rate" will
assume a liquid phase outflow.
· Liquefied Gas from Long Pipeline: The "Liquefied Gas Spray Release" model has also been integrated
within the "Liquefied Gas from Long Pipeline" model, avoiding the required linking of this model to obtain
inputs for a dispersion or pool evaporation model.
· Liquefied Gas Spray release model: (now integrated in liquefied gas releases): The calculation of the
Mach1 gas velocity (applied as limiting value) has been improved and now uses correct vapour end
temperature. The integration of the spray model inside liquefied gas release models also implies that
stand-alone "Spray Release" calculations, that were previously NOT linked to any liquefied gas release
calculation, cannot be automatically converted into the new "Liquefied Gas Release" model (because
many inputs are missing). The log message will contain a warning for this incomplete model conversion.
· 10 minutes release models and 10 minutes LOC scenarios: The calculation of a hole-size leading to a
specific "representative rate" to empty the vessel in specific time (the so-called 10 minutes model) has
been moved to the corresponding outflow model itself. The input choice "type of vessel outflow" now
contains 4 choices: "Release through hole in vessel" / "Release through (a hole in) pipe connected to
vessel" / "Fixed flow rate" / "Vessel empty in specified time" of which the last choice reflects the
previous "10 minutes" model. As a result, the 10 minutes and G2 LOC scenario's for gas, liquid and two
phase have been removed. When opening a 10 minute model as stored by a previous version, it will be
converted into the corresponding release model. The release models will now always report a "hole
diameter used" which will be linked to following (jet fire or dispersion) models.
We abandoned the (G1) and (G3) name additions in the combined models and now simply refer to "LOC
Instantaneous release", representing the catastrophic failure of a vessel, and the "LOC Continuous Leak"
for any big or small leak-rate situation.
· Pool evaporation: The input parameter "North/South Latitude" will now be hidden whenever "user defined
solar heat radiation" is applied, because latitude doesn't influence results for this choice.
· Overpressure damage calculation: The translation from overpressure towards lethality has been
improved, avoiding some initial lethality levels between 0 and 1 m distance if the associated threshold
pressure was never reached.
· Congestion areas: The rare situation where all borders of a congestion area were identified as being out
of reach of a LFL cloud, while the release coordinate itself is actually within this congestion area, will
now calculate a cloud overlap flammable mass and report VCE explosion phenomenon.
· Pool fire model: The side-view of the rim fire shape is no longer provided because it gave an unrealistic
visualisation of radiation.
· User interface: Potential error messages when using unrealistic ambient pressure or ambient
temperature values are avoided.
· User interface: A potential access violation error when exporting a graph with an empty dataset has been
caught.

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EFFECTS version information 7
Version 12 release history

· User interface: The ordering of input parameters has been made more consistent in all (combined)
models.
· User interface: The help desk contact option, previously only accessible in the Help..About box, has
also been added to the main menu under "Help".

EFFECTS 12.1.1 (July 2023) Version Info

This is a small bugfix release, no changes to the models were made.
· User interface: project tree: An issue has been resolved that could freeze the application upon pasting
invalid data.
· Installer: Fixed signature mismatch in a 3rd party dll.

EFFECTS 12.1.0 (March 2023) Version Info

The latest version of EFFECTS & RISKCURVES, “v12.1 Victor”, has been named after Gexcon
Netherlands’ former General Manager, who recently retired. This is to show the EFFECTS & RISKCURVES
team’s appreciation for his dedication to the success of EFFECTS & RISKCURVES for many years, as
well as for the endless guidance and support provided. With this new release we honour years of excellent
leadership and celebrate the legacy of hard work and commitment Victor leaves behind.

· University edition version: A project loading issue has been solved.

· User Interface: Dynamic grid presentation: The responsiveness of the dynamic dispersion’s visualisation
has been improved. Furthermore, the calculation domain and colours in the legend have been adapted.
The flammable dispersion model, will show the dynamic cloud development for up to 25% the LFL
boundaries and LFL related colours.The toxic dispersion model will use 1% LC (Lethality Concentration)
as calculation domain and illustrate thresholds related to various % LC levels. The dispersion
concentration cloud model will use the lowest requested concentration threshold (from presentation
settings + user defined) as domain, and can now use a user specified threshold for colour translation of
the dynamic grid. The storage of the dynamic grid is now more efficient and creates significant smaller
project files.
· User Interface: Chemical editor: The icon for a "user defined" chemical has been adapted, creating a
more clear difference between official DIPPR data and modified user substances.
· User interface: Measurement ruler: The behaviour of the measurement tool is now more intuitive. It now
immediately shows distance between the first selected coordinate and the (moving) cursor and does not
wait until a second point is selected.
· User interface: Map view: The positioning of the North Arrow and the Scale bar relative to the map has
been improved. Furthermore, the responsiveness in refreshing a tile server and showing the equipment
locations has been improved. If the background map fails to load, a more adequate error message will be
shown. A surrounding contour (dotted surrounding circle) can now also be shown if the map does not
have the equipment location.
· User interface: Graph view: A scaling issue when changing axis units in a comparison set has been
solved; all selected graphs will now react to selected axis units. When using the graph expert editor,
removing series no longer creates an error, although we strongly advise to un-tick a line in the legend to
hide a specific graph.
· Dispersion model: A potential fluctuation in the graph "max. concentration vs distance at Zd", rarely
occurring at very short distances, has been solved.
· Dispersion model: The trajectory calculation of vertical jets has been improved. This may influence
calculated concentrations for this typical release situation, especially at short distances where vertical
jet plume rise influence is expected.
· Dispersion model: When using a (horizontal or vertical) jet release calculation, the dispersion model
performs a phase detection check to either ask for "expanded diameter" and "liquid fraction" for 2 phase
releases, or "hole dimensions" and "exit pressure" for gases. In case of gases, these inputs would
trigger the integrated turbulent jet calculation. This phase detection mechanism has been improved, now
using pressure + temperature to distinguish the substances phase. Additionally, when using chemical
mixtures, the model is now less restrictive and accepts potential multiphase mixtures.

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EFFECTS version information 8
Version 12 release history

· Toxic Dispersion model: The concentration time behaviour for semi-continuous releases has been
improved. This change tends to lead to larger lethality fractions at shorter distances, because the rapid
concentration decay after end of release is now more smooth.
· Vulnerable Area calculation: A potential underestimating of toxic victims in a vulnerable area, occurring
for small area's (compared to the toxic grid cell size) has been fixed.
· Combined LoC model liquefied gas G2 G3: When combining a jet release source rate (airborne fraction)
with a pool evaporation rate (rain-out fraction), the model will now select either "horizontal jet", "vertical
jet" or "pool evaporation" for the dispersion, based on selected outflow angle and most dominating
source rate.
· Spray release model: This model has been improved to be able to deal with situations where all liquid
droplets flash out, which could previously lead to misleading answers in top venting situations. Moreover,
the model now correctly applies a contraction coefficient, which should be included to obtain effective
outflow area. This modification may lead to slightly altered calculated liquid fractions in the aerosol but
does not influence rain-out behaviour.
· Pool evaporation model: When switching from land to water in the evaporation model or vice versa, the
subsurface roughness types will now be adapted accordingly. This avoids misusing associated minimum
pool thickness heights, which are specific for land or water.

EFFECTS 12.0.1 (November 2022) Version Info

(version 12.0.0 has been an internal release version)

Important changes in version 12:

· Licensing: The software now supports cloud licensing, offering the flexibility of a network license without
the need for setting up a company license server. For more information, contact effects@gexcon.com.
· Installing: The installation of the driver for the license system is now optional.

· User interface: We have redesigned the user interface, not only changing the main icon, but also
adapting button images and several interface elements, creating a more fresh and clear user experience.
The main screen layout and position of interface elements has hardly changed, so the way of working
with the software remains identical. Several specific GUI elements have been improved, such as menu
structure, the side bar panel and map legend panel, which can now be unpinned, allowing more space for
the map. The new user interface fully supports high resolution displays and display scaling options.
· User interface: The assignment of "normal" and "expert" parameters has been adapted. Most parameters
will now already be shown in "normal" mode, while only a few parameters can be considered to be real
"expert" parameters, which rarely need to be adjusted. Simple mode remains the same, showing a
limited list of inputs, while "expert mode" will now only be required in dedicated situations.

· Dispersion modelling: The emphasis of this important major release is on dispersion modelling. The
improved dispersion model supports and correctly predicts the rising behaviour of "lighter than air"
releases from grounded over transitional to fully lifted-off. Obviously, this was done to comply with the
growing demand to predict hydrogen releases. However, these modifications also affect substances like
ammonia (which is lighter than air as pure ambient temperature dry gas) and methane, because the
prediction of potential rising gasses has changed considerably. The full potential transition from heavy to
neutral to lighter than air (triggered by heat exchange) is now modelled adequately by ONE model.
· Dispersion modelling: The use of hydrogen also introduces much higher storage pressures, for which the
influence of the turbulent mixing (high speed jets) is of great importance. To deal with this impulse driven
dilution phase, the turbulent jet model is now an integral part of the dispersion models. The turbulent jet
model itself has also undergone major improvements resulting in more accurate results in the full velocity
range from sub-to supersonic flow. For highly under-expanded jets, the results are less conservative
compared with version11.
· Dispersion modelling: The flammable cloud and concentration dispersion model now shows
"surrounding" contours which follow the cloud centreline height, and additionally present contours at
specified reporting height Zd. The "Dynamic concentration" cloud presentation will always represent
concentrations at this reporting height. Additionally, the calculation of flammable cloud contents (mass,
area and volume) had to be adapted, now following the potential rising cloud centreline height.

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EFFECTS version information 9
Version 12 release history

· Dispersion modelling: Because the new dispersion model model also features the previous heavy gas
model and has been extended for "non heavy" (including lighter than air) behaviour, we no longer require
a choice between "heavy" an "neutral gas" dispersion. The "neutral gas dispersion" model is still
available for dedicated real passive situations, but the advise is to use the new generic "dispersion
model" for standard situations. Therefore, this model has is now called "Dispersion model" and replaces
the "Heavy gas dispersion model".
· Dispersion modelling: The modelling of vertical jets has been improved and made more consistent. In the
past, a special treatment of the release terms with source term densities close to the one of ambient air
was applied. In this case, a representative jet source term was located at a specific height starting in
horizontal direction. In the new dispersion model this behaviour is removed and all release term densities
from heavy over neutral to light are treated by one consistent model. In addition, the dispersion model for
vertical jets is modified and shows improved results for light and heavy gas releases compared with
experimental data.
· Combined LoC models: Because the improved dispersion model is the preferred and most realistic
model, the combined LoC models no longer runs the neutral gas dispersion model for "non heavy"
situations. We have concluded that this neutral model might be too conservative for specific situations,
and excludes correction for several potential relevant physical phenomena (such as ground effects,
entrainment due to influences of velocity and density influences, and turbulence introduced by the
release itself). Therefore the new dispersion model is used as standard for the LOC models.
· Combined LoC models: The "outflow angle in XZ plane", which is important for the potential jet fire flame
orientation, is also being used to determine the dispersion type. Angles smaller than 45 degrees will be
modelled as "horizontal jet", any angle above 45 degrees is considered to be a "vertical jet release" for
dispersion.
· Neutral gas model: The neutral gas "Jet release" mode already combined "turbulent jet" with a fully
passive dispersion. In version 11 a discontinuity in concentration level when switching from jet to passive
dispersion could occur. This behaviour (basically a too high velocity at the interface from "turbulent jet" to
"passive" dispersion) has been improved, leading to smooth transitions and considerable smaller
distances for jet releases. Note that we now advise to use the new generic dispersion model for gaseous
jet releases, this model also includes more detailed physics like the potential buoyant behaviour of the
plume. The fully passive jet modelled distances, as predicted by neutral gas for non or low-buoyant
conditions, are now more similar to those predicted by the new dispersion model, but still might differ for
non-passive releases.

More technical documentation, describing detailed mathematical background and showing verification and
validation of the adapted methods will be provided in the documents section of our download portal.

· BLEVE fireball model: The experiments, conducted during the SH2IFT program, showed that a LH2
(liquefied hydrogen) BLEVE actually can occur, but that its heat radiation is very low. According to
experimental values we have reduced the SEP (Surface Emissive Power) for a hydrogen BLEVE fireball
to 70 kW/m2. This low SEP value was already applied for then hydrogen jet fire and LH2 pool fire.
· Project file versions: We have been able to keep the same file format (a compressed XML type) and
version 11 files can be opened directly in version 12. Unfortunately, we cannot guarantee downward
compatibility. For this reason, we advise to keep project files separated and distinguishable by file or
folder naming. The support for version 9 and 10 has been skipped, version 12 no longer reads old
".Effects" extension type projects. Users should apply version 11 to convert version 9 or 10 files to the
current .Effx format.

Version 11 release history

EFFECTS 11.5.2 (March 2022) Version Info
This release only contains changes relevant for users with a university edition license.

· Resolved an issue where loading a university edition project could cause errors depending on the
computer configuration.

EFFECTS 11.5.1 (December 2021) Version Info

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EFFECTS version information 10
Version 11 release history

· Several stability improvements for handling large projects.

EFFECTS 11.5.0 (November 2021) Version Info

· User Interface: Project file opening: Opening a project file by double-clicking could trigger errors as a
result of the recently introduced asynchronous method of loading and activating the user interface. This
potential problem, occurring on very fast PC's, has been fixed.
· User Interface: Multi language support: The EFFECTS user interface can now also be switched to
Spanish (see Edit-Options,Language). The translations (Chinese and Spanish) in the chemical editor
have been extended with translated names of chemical properties.
· User interface: Calculate from here: When using the option to just calculate one specific node of the
project tree, the project file will no longer be backed up before calculation. This improves responsiveness
of the program when working with large projects, but should be used with caution. When the user has
made considerable changes to the project, it is advised to use the "Calculate" button, which will create a
full back-up of the project before initiating the calculation.
· User interface: Loading older version projects: When loading projects from earlier editions (version 9 or
10), recently introduced or modified parameters will also be automatically adjusted to defaults.
· Calculation speed: EFFECTS will now also perform parallel model calculations. This implies that projects
containing multiple equipments or models will be calculated much faster because models will be run
simultaneously, using multiple processor cores. The potential speed improvement will of course depend
on the number of cores of the processor.
· Flammable dispersion models: The determination of flammable mass and flammable volume of a cloud,
requiring a volumetric integration of concentrations, has been converted into a multi-threaded calculation,
speeding up these specific models as well (both dense gas and neutral gas flammable cloud). The graph
of the flammable cloud volume vs time has been corrected, the volume will now always reduce to exactly
zero after the LFL cloud has passed.
· Pool evaporation model: The modelling of boiling (cryogenic) pools from water surface has been adapted.
When using the boiling pool from water while using a confined water surface, the model would assume
there was ice formation, and switch to another heat transfer regime. This behaviour might occur only at
small scale (like experimental) releases and is now abandoned. The model will now show similar heat
transfer behaviour as with unconfined (free spreading) boiling pool from water. Furthermore, both the
"confined boiling from water" and "instantaneous boiling from water" situations will now also fulfil
minimum pool thickness requirements and no longer lead to an infinitely thin pool layer thickness. This
modification may lead to significant lower evaporation rates and longer durations for confined or
instantaneous Propane or LNG on water situations.
· Combined LoC G2 models: The "release within 10 minutes" no longer accepts modelling a pipeline
connected to a vessel. This release mode, intended to represent a high impact non instantaneous
scenario, should model a large release directly from a vessel, applying the associated hole in the vessel.

· Combined LoC G3 models: When using the "fixed flow rate" method in a G3 (leak) calculation, reloading
the project could trigger an "Out of date" warning, requiring to recalculate the model. This inconstancy
has been fixed.
· Gas and BLEVE fireball models: The heat radiation side-view graph has been improved, and will show
contour dimensions that can differ from the top view shown on the map, which is reporting at a specified
height Zd.
· Toxic dispersion models: A potential issue with a "frozen" calculation while searching for an extremely
high dosage or very low concentration (toxicity indoors) has been fixed. Furthermore, a "grid spacing
error" that might occur when dealing with negligible releases (never reaching lethal levels) has been
solved.

EFFECTS 11.4.2 (August 2021) Version Info

· Toxic dispersion models: For very small releases an issue could occur presenting the contours. This
issue has been identified and resolved.

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EFFECTS version information 11
Version 11 release history

EFFECTS 11.4.1 (July 2021) Version Info

· User interface: multiple language support: The Chinese translations have been improved.

EFFECTS 11.4.0 (July 2021) Version Info

· User interface: multiple language support: The EFFECTS user interface can now be completely switched
to Chinese language. Other languages will be made available in the near future by providing additional
language packs.
· User interface: shifted release location on copy: Some users experienced an annoying shift of the
release location when performing a “copy to clipboard” of the map view. This issue has been fixed in
version 11.4.
· User interface: responsiveness while loading and saving. When loading and saving large projects the
application could appear to be “frozen”. This no longer happens and additionally loading- and saving
times have been greatly reduced.
· Pool fire model: When applying very short duration continuous release scenario’s, where pool spreading
is not finished when the release stops, the pool fire would switch to instantaneous mode. In those
situations, the pool area would be set to the defined max. pool area. The improved model will now also
check for minimum pool thickness and potentially apply a smaller pool size if the amount of liquid cannot
cover this max. area.
· Pool evaporation model: The calculation of typical heat transfer coefficients will now use actual air
temperature to obtain intermediate values like Prandtl number, kinematic viscosity air, conductivity air
etc. This might lead to slightly different evaporation rates, especially if the provided ambient temperature
deviates substantially from normal (293 K) conditions.
· Toxic dispersion models: The toxic dose dispersion model will now also report indoors toxicity contours,
when indoor toxic calculation is activated. Furthermore, the cut-off distance of a toxic calculation will no
longer be influenced by a potential “user defined dosage”, which could previously lead to a different
calculation domain and thus calculation accuracy.
· Toxic dispersion models: The calculation of indoor toxicity can now potentially include a limited exposure
duration. This requires an additional user input “Use exposure duration limited indoors toxicity (Yes/No)”,
which is only needed when activating the indoor toxicity calculation. In previous versions, we would
simply assume that the indoors location would be the escape location, implying that people would
continuously be there. This previous method (=selecting “No”) would mean that if a concentration would
build up inside, it would also decrease slowly after the cloud passed, potentially still leading to
substantial lethality indoors due to long lasting concentration exposure. By selecting “Yes” the inside
concentration time graph, which is determining the accumulated dosage, will also be limited to the user
defined exposure duration (default 1800 sec). This situation would represent total evacuation of the
population after exposure duration. This choice obviously has an important influence on the inside
lethality result.
· Vulnerable Area Indoor Toxicity: When applying a vulnerable area as a receiver of a toxic cloud, this
exposure duration cut-off is not used, but users can define a ventilation shut-down time and reduced
ventilation rate. These choices can also be used to evaluate effect of increased ventilation after the cloud
passed by (entering an increased ventilation rate). The vulnerable area will no longer provide an error
message when placed far outside reach of a toxic cloud.
· Combustion and toxic combustion products model: This model now supports the usage of any
solid/liquid mixture defining the material getting burned. This enables specifying a warehouse fire
“average storage composition” based on multiple (solid and liquid) substances which can be selected
from the chemical database.
· Unified Release and LoC models: These combined models, capable of modelling gas, liquid and two
phase releases, could still ask for an input pressure, while the user actually selected “fixed flowrate”
requiring a calculation of this associated pressure. These unnecessary inputs are no longer required.
· Storage format: The project files are considerably smaller but are not backward compatible. Therefore
projects saved with version 11.4 cannot be read with previous versions.

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EFFECTS version information 12
Version 11 release history

EFFECTS 11.3.0 (March 2021) Version Info

· Combined models two phase releases: These models are now capable of dealing with vapour outflows
from top vent PLG releases. Due to turbulent expansion of the pressurised dry vapours, these releases
tend to disperse as a neutral gas (no droplets, no cooling by flashing).
· All release models: Apart from reporting the density (which is potentially after turbulent jet expansion if
relevant) all release models will report the suggested dispersion strategy to be applied for the following
dispersion phase. Pure liquid models will of course need the pool evaporation model to make this
evaluation.
· Heavy gas and Neutral gas flammable cloud models: In addition to footprint area and mass in the
flammable cloud the models now also report volume of the flammable cloud (also versus time). This can
be valuable information when doing congestion assessments. In case a 50% LFL footprint is requested,
the volume will be based of 50% LFL threshold, but flammable mass will always be based upon 100%
LFL threshold.
· Heavy gas dispersion model: The presented cloud sideview has been corrected slightly to avoid artefacts
in the tail of the contour.
· Jet fire model: When using the jet fire model with pure Hydrogen, the model will now apply a reduced
Surface Emissive Power, which reflects the low radiation flux of this material.
· Plume rise from fires model: The model now accepts any chemical to be monitored. When connecting
the plume rise to the toxic combustion model, the associated combustion product source rate will be
linked automatically.
· Gas outflow and long pipeline models: The gas release and Gas or PLG long pipeline model now use the
same friction factor calculation method. Furthermore, the incorporation of user defined pipeline
roughness has been improved.
· Importing issues solved: Reading in a version 10.1.4 combined model in version 11 could trigger an
unexpected error. This issue has been solved. As of version 11.2 the “Outcome” phenomenon BLEVE
fireball will now correctly be translated into “Gas or BLEVE fireball”. File reading problems with the
educational version (university edition) have been fixed.

EFFECTS 11.2.2 (January 2021) Version Info

· Pool evaporation model: When applying an atmospheric pressure that leads to a lower boiling point, the
boiling point will be adapted accordingly. Furthermore, heat transfer from subsoil will be based on real
pool temperature, which can be potentially lower than Normal Boiling Point for boiling liquids.
· Neutral gas dispersion: In case the source type is an “Evaporating pool release” the dispersion results
will now start at the pool centre, avoiding concentration discontinuities that occurred within the distance
range of the pool radius.
· Heavy gas dispersion: The cloud sideview for instantaneous releases could present misleading and
wrong contours, especially in case of rising behaviour. This sideview presentation has been fixed,
although we still advise against the use of this model for lighter than air situations.
· Combined Unified LoC model: If the user selects “fixed flowrate” as release type in a G3 continuous
leakage scenario, the vessel dimensions are not relevant, and will no longer be presented after some
change of process conditions.

EFFECTS 11.2.1 (November 2020) Version Info

The substantial modifications in version 11.2.0 unfortunately also introduced some potential issues, which
justified a subsequent minor release:
· Project file read problem: In some occasions, users have experienced project file read errors, not
allowing them to open an existing project in version 11.2.0. This appeared to be the result of having
duplicate user defined chemicals stored in multiple user databases. This has been fixed, but in general,
we advise not to make file copies of user databases (.tci files) and have both of them attached (edit-

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EFFECTS version information 13
Version 11 release history

>options->chemical databases list): they will both contain the same chemicals, leading to ambivalence
which properties from which database are used.
· Dense gas toxic dose model: Version 11.2.0 introduced a problem in case an additional “user defined
dose” contour was selected. This issue has been fixed.
· Neutral gas dispersion models: The presentation of the dynamic (=time depending) concentration grid is
now skipped when using a “continuous” (infinite duration) source. This non-relevant combination could
previously lead to an infinite calculation because the end time for the concentration profiles was never
reached.
· Combined LoC gas G3 model: This model could incorrectly flag a gas as a PLG when using the “fixed
flowrate” method, because input pressure is unavailable and atmospheric pressure was assumed. This
problem has been solved.
· Liquefied Gas spray and instantaneous models: In case the ambient pressure is lower than standard
atmospheric condition, the temperature of the pool is now adjusted to the ambient pressure boiling point
instead of its “Normal” boiling point (NBP). This avoids the phase detection mechanism flagging this
liquid as a gas in a following pool evaporation model (or within combined PLG models).

EFFECTS 11.2.0 (November 2020) Version Info

· Gas fireball model: a completely new “Gas Fireball” model has been added. This model replaces the
previous “Flash fire (Instantaneous release)” release model, but is different from the BLEVE fireball
model, which is only intended for two phase (evaporating liquid) fireball situation. The previous flash fire
model, merely calculating the required diameter of an Upper Flammability Limit (UFL) concentration
hemisphere, could underestimate the fireball and heat radiation effects of direct ignition events of
instantaneous gas releases. The new model also includes prediction of overpressure effects (Gas blast)
upon sudden depressurisation. A full model theory background document can be obtained from our
download site.
· BLEVE and Gas fireball models: The fireball models now also present heat radiation and lethality grids,
allowing to read out results at a specific coordinate using the map crosshair tool.
· Combined models: After reconsideration of potential event trees it was concluded that instantaneous
releases of both gasses and PLG’s could always lead to “blast” phenomenon, due to the rapid
depressurisation wave. This Gas or BLEVE blast phenomenon is even relevant in case of non-flammable
substances and is now specifically included (see ‘outcome’ selection) in the corresponding combined
model calculation.
· Gas instantaneous release model: This model replaces the previous “expansion to UFL hemisphere”
procedure and is to be applied if there is no direct ignition. Because mixing with air to UFL level is no
longer included, the end temperature can be substantially lower, now leading to a “heavy gas” situation
after the associated expansion cooling. Therefore, following dispersion model results may be affected by
this modification.
· Neutral gas dispersion models: Because users were often having questions about the required
application of the “Gas Turbulent Free Jet” model, this model has now been integrated within the neutral
dispersion models. This also allowed to improve the connection of a “turbulent free jet” model to the
dispersion model and avoided the observed sensitivity for the jet “threshold concentration”. The
integration allows to directly connect the neutral dispersion model to any gas outflow model and
potentially shows all requested concentration levels obtained within the turbulent jet zone itself.
The integrated dispersion models now contain a choice “type of continuous source” which can be
“evaporating pool release” (requiring pool area), “jet release” (requiring outflow parameters including angle in
XZ plane) or “User defined window” (requiring initial source dimensions). In case of a jet release the model
will run an internal “turbulent jet” calculation, translating the concentration profile at the end of the jet into
corresponding offsets and starting conditions for passive dispersion. The background of this integration is
described in a technical document available on our download site.
· Gas turbulent free jet model: This model is no longer selectable as a separate model but integrated into
all neutral gas models. This also avoids the inappropriate connection of a turbulent jet to a heavy gas
model (the heavy gas model already contains jet momentum correction and never accounted for
predilution obtained within the turbulent jet).
· Toxic dispersion models: The toxic dispersion models will now also report an “Indoor concentration vs
time graph”, in case an indoor toxicity calculation is performed. This allows to evaluate the effect of a

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EFFECTS version information 14
Version 11 release history

delayed build up and decay of concentration, potentially even leading to higher lethality. When using a
vulnerable area with a dedicated “ventilation shutdown time” with its changed ventilation rate, these
graphs can even show the influence of a potential quick shutting down of ventilation or opening up
windows after a toxic cloud has passed. Examples are shown in the installed “LPG tank receiving
objects” demo project.
· All models: mixture phase check warnings: Potential misjudgements in the identification of a mixture
phase have been fixed. As a result of the applied tolerance in the phase check procedure (see version
info 11.1.0), pure gaseous mixtures or pure liquid mixtures could incorrectly get identified as being a
PLG (Pressurised Liquefied Gas) at the provided temperature and pressure. Furthermore, typical liquid
models will now also accept mixtures in “Multiphase Liquid-Solid” situations, as long as the pool
temperature is above the mixtures combined melting point.
· Mass–Volume calculator tool: The mass volume calculator no longer creates an error message “property
not all available” when evaluating mixtures.
· Flammable cloud and fire models: The test for required chemical properties like LFL,UFL and heat of
combustion could fail for flammable mixtures if one of the components was a non-flammable substance
(like Water or Nitrogen). This issue has been solved.
· Dense gas models: A rare “double array spacing” error, which could occur in the dense gas models
while trying to generate a contour with low resolution and small release rate situations has been fixed.
· Pool fire model: The heat radiation sideview grid (providing a X-Z axis cross-section view of the heat
radiation intensity) for polygon shaped fires is now correctly positioned along the flame transect axis.
· Toxic combustion products model: The pool temperature is no longer required because the model now
applies ambient temperature and normal boiling point to calculate the associated burning mass flux of a
selected liquid substance.
· Liquefied gas long pipeline model: The model no longer requires the availability of the “heat of
combustion” as a chemical property, because this model is also valid for non-combustible substances.
· Sample mixtures: The sample mixture “winter grade Gasoline” has been adjusted to be a pure liquid at
expected ambient temperatures. The associated heat of combustion and burning rate haven’t been
changed, giving it an identical result in the pool fire model.

EFFECTS 11.1.0 (June 2020) Version Info

· User interface: We have been aiming to simplify the user interface. This has been archived by both
grouping the parameters (input and result panels) and by hiding the previously only disabled inputs. This
resulted in an important change of the number of parameters shown, but also in the ordering of
parameters. We realise that this might need some adaptation to get used to this new layout, but we are
confident that this way of presenting provides a more structured and less overwhelming list of inputs and
results.
· User interface: When loading a previously calculated combined LoC model, the result reports will now
skip listing parameters of models that did not run and will also provide a sub-model input-output report.
This more intelligible report was previously only shown upon calculation of a combined model.
· User interface: We have also reorganised and reviewed the number of log messages that could be
presented. The number of messages has been reduced, and as of this version, the yellow
warning message should really be considered as a reason to check the log message. Typical feedback
messages about resizing source dimensions or database range limitations are now provided as pure
informative messages, because these aspects do not influence the reliability of results. An explanation
of the most common warning messages has been added to the user manual.
· User interface: End models will now always provide a warning if a requested contour level (concentration,
heat radiation, over pressure or lethality level as defined in “presentation settings”) is not reached and the
corresponding threshold contour cannot be drawn.
· Explosion models: A potential adjustment of the reporting distance Xd in explosion models, which was
merely reported in the log, is now abandoned. Reporting of explosion overpressures at Xd is now skipped
IF this distance is out of range of the explosion calculation (overpressure at those distances is already
below any damage level).
· Pool fire model: The unintended rotation of the heat radiation grid in case of a rectangular or polygonal
shaped pool has been fixed. This issue was introduced in version 11.0.7 when we started to show the
side view grid in the correct wind direction.

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Version 11 release history

· Pool fire model: If the chemical database does not contain a pre-defined value for the burning mass flux,
the so-called Burgess relation will be used. This relation (YB equation 6.67) has been extended to the
official literature’s formulation, which is more accurate for non-PLG situations.
· Pool evaporation / pool fire phase check warnings: As a result of a more systematic phase check
procedure, some flashed liquids (rained out at their boiling point), would be flagged as being a gas. This
problem was caused by a substantial difference between the provided normal boiling point and the vapour
pressure relation in the database. This issue has been solved by increasing the tolerance between
atmospheric pressure and vapour pressure at pool temperature. If vapour pressure at provided normal
boiling point differs too much from one atmosphere, a warning will be provided.
· Liquefied gas releases phase check warnings: Both instantaneous and continuous liquefied gas release
models now also accept situations above critical pressure. These were previously flagged as
“compressible liquid” requiring a liquid outflow, although flashing might occur in specific situations. The
phase check (see Mass/Volume calculator for result of a phase state at any temperature/pressure) now
distinguishes “Compressible Liquid” (temperature <= normal boiling point) and “Compressible
PLG” (temperature > normal boiling point)
· Gas release from vessel: The model will also perform calculation if release duration is even larger than a
month. Extreme combinations of large vessels with very small holes could not provide any
“representative rate” if “Calculate until empty” was selected and required emptying time was larger than a
month.
· Combined Unified LoC scenario: In case of a two-phase bottom release situation, the potential jet fire
phenomena will now use the liquid outflow temperature instead of the vapour temperature after flashing,
avoiding phase check warnings. For unignited outflows below liquid level, the spray release model will
determine end-temperature (and potential rainout).
· Dense gas dispersion models: The x-axis range of the maximum concentration versus distance graph
have been reduced to more relevant ranges. If requested concentration levels reach further than 10 km,
the associated contours will still be drawn, but a warning will be provided in the log.

EFFECTS 11.0.7 (February 2020) Version Info

· User interface: Saving of graphs data in spreadsheet format has been improved, now supporting the
latest version of MS-Excel.
· User interface: An error message occurring when showing the temperature dependent property graph in
the chemical editor has been fixed. Unfortunately, this error was introduced in the 11.0.6. release.
· User interface: The Mass Volume calculator tool now also shows substance specific vapour pressure,
boiling point and melting point information. Furthermore, it will now apply “Pressure” and “Temperature”
values as applied in the current active model and will disable access to liquid (or gas) mass / volume
fields if such a phase is not present. The phase detection mechanism itself has been improved, providing
better descriptions of multi-phase situations in case of mixtures.
· User interface: The names of the models have been made more consistent, improving accessibility in the
menu. Several abbreviations or alternative names have been removed, now focussing on describing the
function of the model.
· User interface: All graphs now consistently apply the word “lethality” instead of “mortality” in graph titles
and descriptions.
· User interface: The default US pressure units have been changed to a properly functioning [psi] unit.
· User interface: The use of equipment locations which are very far from one another (>50km) will now
create a warning because these situations can lead to inaccurate contour scaling, resulting from
projection system corrections.
· Dense gas dispersion model: A potential error message, triggered when applying the model for “lighter
than air” situations has been fixed. The model now gives a proper warning in the log window when dense
gas model is applied for “lighter than air” situations. Although this model predicts a rising behaviour, we
discourage the use of this model for these situations, especially for Hydrogen where concentration
predictions should be considered untrustworthy.
· Neutral gas dispersion model: When connected to a Turbulent Free Jet (TFJ) model, the sideview
contours will now also be combined with the TFJ expansion zone, illustrating the initial offset (X and Z) of
the contours created by the jet.

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EFFECTS version information 16
Version 11 release history

· Fire models: The heat radiation sideview graph would trigger an error when attempting to change units.
This issue has been solved.
· Pool fire model: When applying a rectangular or polygon shaped pool fire the side-view grid (shown in the
map view) will now also be rotated according to the applied wind direction.
· Rupture of vessels model: The chemical properties check, introduced in 11.0.6 would always require
“heat of combustion” for the chemical being available. This property-check has been adapted, now only
checking for chemical info applied in the selected cause of vessel rupture.
· Toxic dispersion models: When applying these models with a toxic mixture, the chemical properties
check could warn that toxic Probits are not available, if mixture toxicity was not yet evaluated in the
chemical editor. This behaviour has been improved.
· Release in 10 min outflow models: The “Fixed flow rate” choice, occurring when linking the 10 minutes
release to another release model has been disabled, avoiding conflicting input.
· Liquefied gas vapour venting model: A potential floating-point error when applying 100% filling degree has
been avoided. The graph total mass released versus time has been corrected for deviations related to
compressibility.
· Combined LoC Release in 10 min scenarios: The phase detection, applied in the “release within 10 min”
combined models, has been improved. The absence of an initial pressure input could give a misleading
Liquid/PLG/Gas phase warning.
· Combined Unified LoC scenario: The switch to a “long pipeline” model whenever the pipeline length was
more than 10 km has been removed. This situation would subsequently assume a blocked pipeline
which is totally different from the intended “release from a vessel” scenario.
· Combined Unified LoC scenario: In case of a pure vapour vent from a PLG vessel (leak above liquid level)
the model will also apply a turbulent jet expansion zone.

EFFECTS 11.0.6 (February 2020) Version Info

· User interface: The test for graphic display capabilities using a unique Windows10 call has been
modified. Although Windows 10 is the only officially supported system, this now allows EFFECTS to run
in older Windows 7 or Windows 8 operating systems.
· User interface: The export of equipment locations as a shape file has been enabled.
· All models: Before calculating the consequence model, a check has been added on availability of
required chemical properties for the specific calculation. If a specific property of the substance is not
available in the database (e.g.: viscosity data is required in an outflow model), the model will now stop
and provide a specified “missing property” error message, avoiding unclear internal errors.
· Pool fire in Combined LoC models: When calculating a rectangular or polygonal shaped pool fire, the
heat radiation contours could appear rotated in vs 11. This behaviour has been fixed.
· Pool fire model: When using a rectangular or polygonal pool fire, the contour dimensions are now
correctly reported as valid in the applied wind direction. Note that the min/max distances relate to the
provided equipment release coordinate, which can be outside the pool for a free drawn shape.
· Dispersion models: The potential X offset applied in the dispersion models is now also incorporated in
the sideview contours and concentration versus distance graphs.
· Gas release long pipeline model: The long pipeline model now includes the standard “hole rounding /
discharge coefficient” inputs correcting for outflow area. The use of (small) “hole in pipeline” choice has
been skipped because this would only generate an averaged outflow based on blowdown time, which is
often not “representative”.
· Gas release turbulent free jet: The reporting of the “distance to threshold” has been adjusted to always
represent the maximum end distance within the expansion. The model could previously report a zero or
negative values when concentration at the end was still clearly above threshold.
· Liquefied gas spray release model: The accuracy of the model has been improved by using chemical
properties, temperature and pressure in the applied “Schmidt number”. The applied Schmidt number is
explicitly reported and based on diffusivity calculated according to the “Fuller” relation.
· Liquefied gas bottom release: A bug when using “hole in pipe” in a situation with pipeline length < 0.1m
(therefore forcing pure Bernoulli outflow) would apply the pipeline area instead of the hole area. This issue
has been fixed.

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EFFECTS version information 17
Version 11 release history

EFFECTS 11.0.5 (January 2020) Version Info

· User interface: When applying tile server background maps, users can now define the corresponding
coordinate system applied by the tile server URL. To increase loading speed, it is advised to also use
this coordinate projection system in presentation settings, so applying it in the whole project.
· User interface: The tile server address of the “OpenStreetMap” tile server has been changed to comply
with legal usage conditions.
· Combined Unified LoC model: The version 11.0.4 change in the pool evaporation model would require
subsurface roughness to be entered while substance is in gas phase. This input field is now properly
disabled for pure gas situations.
· TNT explosion and Toxic combustion model: These models now use a new “combustible” chemical filter,
which does not require flammability limits but merely a positive heat of combustion for the substance
(=negative “Enthalpy of combustion” value in database).

EFFECTS 11.0.4 (December 2019) Version Info

· Setup / Installation: A dedicated LEGACY version of the software is available to run the software with
original black dongles provided until end 2018. Note that a network license system can only be run with
the new red Gexcon dongle type.
· User interface: Adding a model from the expanding side-panel or menu-bar will now also add a linked
model when being activated with an intended parent model selected in the project tree.
· User interface: The unintended change of a combo-box by using the mouse-wheel when hoovering over
an inactive input panel has been blocked.
· Pool fire model: When using the two-zone model in combination with Methanol, the soot definition value
for pool sizes 20m < D < 50m was undefined. This missing value has been added.
· Two Phase Discharge model: The fixed flowrate calculation, using a predefined flowrate in situations
requiring pressures higher than saturation pressure would still report flashing (vapour fraction). This has
been corrected into a pure liquid phase outflow.
· Pool evaporation model: The pool evaporation from water now also uses the subsurface roughness
parameter defining minimum pool thickness. Added subsurface categories are “Quiet water” for 5 mm
and “Rippling water” applying 20 mm minimum pool thickness.

EFFECTS 11 Release notes (version 11.0.3 November 2019)

(version 11.0.0 to 11.0.2 have been internal release versions)

Prerequisites to run version 11:

· Windows 10 64-bit: EFFECTS 11 has been changed into a native 64-bit Windows application, which
requires a 64-bit Windows 10 operating system on your PC. This enables the software to use all
installed memory of the PC. The software will no longer run on Windows 32-bit or Windows 7 operating
systems. To check whether your version of Windows is 64-bit, look under Control Panel\System and
Security\System, or ask your system administrator.
· USB protection key: EFFECTS 11 has a new licensing system that might require a different type of USB
protection key. The black version 10 protection key will require the “Legacy” version 11 to run. When
using the new red USB dongle, the software can now also use network licensing, potentially available for
multiple users. Furthermore, a single license can be “Soft locked” to a single PC not requiring a USB
hardware dongle. Details about the licensing possibilities and activation procedure are provided in a
dedicated “License Information” document.

Important changes in version 11:

· Installation: the installer is now an MSI-based installation, allowing easier roll-out and integration into
company in-house application catalogues.
· User interface: the program is built with the latest version of the GIS-mapping and graphical tools,
leading to slightly altered “expert” dialogs in the graph- and map result pages.

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EFFECTS version information 18
Version 11 release history

· User interface: the layer ordering in the legend of the map display panel has changed: the layer at the
top is now actually displayed at the top of the legend. This means that the background map is now at
the bottom of the legend list. Reordering of legend layers, if required, can be performed with a long <left
mouse> click on a layer, followed by a drag action.
· User interface: the graph panel now offers a “colour-line” tool, drawing a horizontal line at any level,
helping to check for exceeding specific levels or thresholds. The graphs properties setting allow changing
the colour, level or orientation
· User interface: the application now supports high-DPI screens, providing sharp and crisp screens on any
resolution, adjusting seamlessly to user display zoom settings.
· User interface: changing a description of a parent model will no longer trigger required recalculation of
linked models.

Apart from these generic adaptations, various model specific changes have been applied in version 11.
· Tank overfilling model: a new “Tank overfilling” model has been added as a liquid release model. This
model describes the vapor production due to a (liquid) tank overfilling scenario, where the cascading
liquid will evaporate while falling down, splashing at the ground, and subsequent pool evaporation of the
remaining liquid. This source rate prediction model can subsequently be connected to a “dense gas
flammable cloud” (or Toxic dose) model as a pool evaporation source to evaluate potential LFL (or toxic)
hazard zones.
· Fire models: all fire models (pool fire, jet fire and fire ball) now also present heat radiation sideview
contours, at the requested levels in “presentation settings”. These sideview contours are shown as a
graph but based on a sideview grid-distribution, which can also be illustrated in the (2D) maps view. Note
that it can be confusing that this sideview grid on the 2D map is shown in the x-y plane but actually
represents the z-plane, visualised in the current wind-direction. To illustrate the location of the sideview
contours and grid, a sideview transect axis has been added to the map.
· Pool fire model: the pool fire model supports the use of heat radiation “shielding” at the bottom of the
flame. This is a situation occurring if a pool is enclosed by a bund or dyke, which is higher than the pool
itself. Also fires inside a tank where liquid level is far below the tank wall can now be modelled using this
“shielding”.
· Pool fire model: the model now includes the possibility to apply a non-burning area, intended to be
applied in case of rectangular or polygonal tank-pit fires. Because remaining tanks within a tank-pit limit
the actual burning area, the pool size, representative diameter and corresponding flame height can now
be corrected for such a non-burning area. The calculation of the representative diameter for polygonal
pool-shapes has also been corrected.
· Pool fire model: the pool fire types “confined” and “unconfined fixed-feed” have been renamed in
“instantaneous” and “semi-continuous”. A semi-continuous pool fire can now be elevated (at height).
· Pool fire model: in case of large pool fires (Dpool > 50m), the two-zone pool-fire model now uses
extrapolated soot fraction behaviour.
· BLEVE fireball model: the BLEVE fireball model now includes an initial height of the tank, potentially
leading to a fireball at a higher elevation. This was added to be able to model a truck on a bridge above
ground level (such as the Bologna accident).
· Neutral gas dispersion model: when using a pool-evaporation source rate (dispersion linked to pool
evaporation or in combined models), the initial source height will now be based on the pool diameter,
using a σz correlation.
· Neutral gas dispersion model: when connected to a Turbulent Free Jet (TFJ) model, the cloud
concentration footprint will now be combined with the TFJ expansion zone, in situations where the
concentration contour is not detached from the source. This can lead to slightly larger LFL clouds, which
no longer have an offset from the release location.
· Neutral gas dispersion model: the concentration contours provided by this model now specifically have a
reference to a height level. This should avoid misinterpretation of flammable contours (always provided at
release height) or contours provided by the “toxic dose” or “concentration” model, which refer to defined
“receiver height” Zd.
· Dense gas dispersion models: the x-axis (=distance or time) points of the graphs have been changed to
provide a better distribution of points along these graphs.
· Spray release model: the model will now raise an error in case of collision of the jet with the ground. This
avoids wrong interpretation of rainout percentages.

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EFFECTS version information 19
Version 11 release history

· Toxic combustion products model: an error leading to wrong flame height in case of solids combustion
has been corrected.
· Liquid outflow model: the model now includes “height difference between pipe entrance and exit” allowing
to incorporate hydrostatic pressure within a non-horizontal pipe.
· BLEVE fireball and BLEVE blast models: these models now include more checks for prerequisite
conditions to have a BLEVE condition: the chemical needs to be a superheated liquid and a warning is
provided if the superheat limit temperature is not exceeded.
· Vulnerable area receiver: When using a vulnerable area for indoor toxicity calculations, the vulnerable
area now allows to use a “Ventilation shutdown time” and “Reduced ventilation rate” (=after shutdown).
This enables the evaluation of response time when shutting down / reducing ventilation. Shutting down
ventilation too late (when concentration inside might already have built up) might even deteriorate the
indoor lethality.

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EFFECTS version information 20
Version 11 release history

Version 10 release history

EFFECTS 10.3.0 (January 2020) Version Info

· USB protection key: EFFECTS 11 has a new licensing system that might require a different type of USB
protection key. The black version 10 protection key will require the “Legacy” version 11 to run. For user
that switch to the new red dongle type (required for network licenses), an adapted version 10.3 is being
released. This version is completely identical to 10.2 but now runs using the red dongle type.

EFFECTS 10.2.0 (January 2019) Version Info

· User interface: The main screen has been adapted with the logo of GEXCON, where we are now
continuing the support and development of the safety software.
· Database editor: The link button to the ICSC website has been fixed. The layout of this site (containing
useful chemical specific properties) had been changed, requiring to adapt the URL to jump to.
· Vessel Rupture model: The initial velocity of fragments has been reverted to the original formula, because
it depends on the total mass of the vessel.
· Congestion areas: When applying a fixed wind-direction for the flammable cloud, the explosion centre
offset is now correctly applied when displaying the overpressure contours.
· As of 2019, the email support address have been changed, support is now continued at
info.effects@gexcon.com (for licensing information) and helpdesk question can be aimed at
helpdesk.effects@gexcon.com.

EFFECTS 10.1.9 (October 2018) Version Info

· Liquefied gas Spray release: The liquefied gas spray release model contains three different sub-models:
a “Yellow book” spray model, a “statistical” spray model which incorporates a droplet size distribution,
and an “Aminal” based model applying a “rule of thumb”. The Aminal model, which is prescribed in
Belgium, has been adapted with some Yellow book relations (using the Aminal based flash/spray
fraction) allowing to get a more realistic diameter of the expanded jet.

EFFECTS 10.1.8 (September 2018) Version Info

· Bleve fireball model: When calculating overpressures due to a BLEVE phenomenon, the Bleve blast
model would apply initial storage condition as starting condition. In case of a hot Bleve however, the
overpressures should be based on temperatures and pressures at failing conditions. This has been
corrected, leading to a higher pressure impact zone for a hot Bleve situation.
· Vessel Rupture model: An index typo mismatch was discovered in formula’s 7.15 and 7.18 of the Yellow
book. When calculating initial velocity of fragments, the mass M applied in these formula’s should be
fragment mass instead of vessel mass Mv. This error was also implemented in the model, and has been
corrected, leading to larger throwing range for fragments.
· Vulnerable Area: A potential error message when applying a vulnerable area, calculating victims resulting
from to a toxic cloud has been solved.

EFFECTS 10.1.7 (September 2018) Version Info

· Comparison sets: Version 10.1.7 fixed a rare case where generating a report in a comparison set could
lead to unhandled errors

EFFECTS 10.1.6 (September 2018) Version Info

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EFFECTS version information 21
Version 10 release history

· Dispersion models: Flammable cloud dispersion models (dense gas, neutral gas) will also report LFL
contours if the associated explosive mass is neglectable. Furthermore the names of the associated
contours are more consistent with concentration level names listed in presentation settings.
· Plume rise from fire: An issue with a potential missing sideview graph has been solved. In situations with
low plume end-height, trajectory calculation points below 1 m height would return erratic concentration
results, resulting in empty sideviews.
· Pool fire inside combined models: The combined models for (continuous) liquid and pressurised liquefied
gasses now also allow the use of non-circular pool fire shapes, just like the stand alone pool fire model
as of version 10.1.5. Note that the pool evaporation max. pool size (m2) input is still required in these
combined models. This input is not associated with specific pool fire dimensions when using non-circular
shapes. Apart from this improvement, an issue with potential rotated pool fire contours for non-circular
pool shapes has been fixed in the combined models.
· Receivers - congestion areas: Overpressure contours around congestion areas are now based upon the
requested peak pressure levels provided in presentation settings. The previously used input “overpressure
level” is skipped and a congestion area will now by default search for worst case wind angle for
flammable cloud overlap.

EFFECTS 10.1.5 (August 2018) Version Info

· Dispersion models: All dispersion models (dense gas, neutral gas and the new plume rise model) now
provide a real “side view” for all requested concentrations levels selected in presentation settings. The
previous sideview would simply plot a “sigma” boundary (parameter describing the vertical dilution factor)
but the side view now gives concentration contours. Setting the Y- and X-axis unit to the same [m] unit
will force an isometric visualisation providing a realistic side view of the plume.
· Toxic dispersion models: The dimensions of a requested dosage contour are now also presented in the
report.
· Plume Rise from Fires model: A completely new plume rise model has been incorporated within
EFFECTS. This model can be connected to a (toxic) combustion model to predict the rising and
spreading of combustion product plumes and provide concentration contours at user defined height
levels.
· The Pool fire model can now also deal with non-circular pool shapes in case of continuous releases (non-
confined pool). It is assumed that the pool spreads circular starting from the release point, but is limited
in its size by the user defined pool-shape. This may lead to smaller footprints than expected because
the defined pool boundary does not get completely filled. Furthermore, the pool size of an instantaneous
pool fires may also be limited by the amount of liquid material and minimum pool thickness.
· The TNT Explosion model now accepts equivalence factor larger than 1.
· The Turbulent Free Jet model has reintroduced the “threshold concentration” input parameter. This value,
used to draw a contour, was forced to LFL for flammables and 1% Lethal Concentration for toxics, but
should be adaptable for substances which are both toxic and flammable. Note that this threshold value
also influences the “Input mass for dispersion” result because material below threshold is considered as
lost during turbulent expansion.

EFFECTS 10.1.4 (November 2017) Version Info

(This EFFECTS update contains only minor improvements and is released together with a potential
important RISKCURVES 10.1.4 update)
· GUI: Exporting background maps: When exporting a background map as pixel based image format
(JPG,TIF, PNG,BMP), without providing the required extension, the graph is now actually being saved, in
the default TIF format.
· GUI: Changing axis boundaries: Adjustment of the X/Y axis boundaries in the graph expert dialog would
often cause an error message when retyping values. This behaviour has been fixed.
· Singapore style lethality levels EFFECTS: When copying a “Singapore blockmode” RISKCURVES
scenario to EFFECTS, the resulting models would also apply discrete 3%, 10% and 50% lethality levels.
This behaviour has been removed in EFFECTS because this method is not relevant for a consequence
calculation.

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EFFECTS version information 22
Version 10 release history

EFFECTS 10.1.3 (November 2017) Version Info

· Dense gas models: A potential error message when calculating a toxic footprints with neglectable toxic
effects is now avoided.
· Turbulent Free Jet model: The reported density was based on pure material at end conditions. This
density is now corrected for the actual end concentration. This implies that the model now reports diluted
mixture density which is to be used to decide to use neutral gas instead of a dense gas.
· Rupture of vessels model: the end point of the graphs is now based upon a 300 Pa end pressure, just as
other explosion models.
· TNT explosion model: the TNT model now also reports Pressure-Impulse and Positive phase duration
versus distance graphs. As a result, the Pressure impulse damage probit relation can now also be used
within this model. The TNT overpressure calculations are no longer based on interpolation of discretised
Yellow Book graphs, but are now using the Kingery-Bulmash correlations for hemispheric surface
explosions.
· Explosion models: all explosion models (Multi energy, TNT and Rupture of vessels) now apply a
logarithmic x point distribution. This will ensure that readouts of higher pressure levels at shorter
distance are more accurate.

EFFECTS 10.1.2 (October 2017) Version Info

· Long pipeline models: Both the Gas long pipeline (Wilson) and Two phase long pipeline models (Morrow)
now include a Yes/No choice “Use double-sided outflow”. Assuming double sided will lead to a double
mass flow during a shorter time, and assumes the outflow is halfway the provided pipeline length. It will
report corresponding “representative diameter” and “pressure” to allow correct linking of the output to
turbulent free jet (gas) or spray (two phase) models.
Furthermore, the long pipeline models now allow to include an inlet flowrate, providing the possibility to
model the situation that the pipeline will not be completely blocked upon rupture but continues to deliver a
(pump inlet) feed after pipe decompression.
· Combined models using gas outflow: The combined models using turbulent jet gas expansion now also
evaluate potential vapour cloud explosion within the expansion zone. These situation will now run a “Multi
Energy” explosion based on the explosive mass and cloud centre which is potentially reported by the
turbulent free jet. This also means that a multi energy model can now be manually linked to a turbulent
free jet model.
· Pool fire and Jet fire models: will now also report projected flame footprint dimensions (as max distance,
min distance, distance to max width and max width).
· Vessel rupture: the input parameter “fraction of liberated energy…” has been removed. This input is only
relevant for “BLEVE overpressure” calculations but forced to 4% according to the advised Yellow book
value inside this calculation.
· Chemical Database: the relevant predefined sample mixtures now include a value for the “burning mass
flux” which might be used in pool fire calculations. These values that were introduced in version 10.0.3
were missing in the 10.1 database. Furthermore, the AEGL values of Hydrogen Fluoride have been
adjusted because they were reported as being incorrect.
· User interface: The display of contours in the map view could lead to initialisation errors upon opening if
the project contained “deselected” contours. This issue has been solved.
· Various small bug fixes, avoiding error messages in specific out of range situations.

EFFECTS 10.1.1 (July 2017) Version Info

· Neutral gas Toxic dose: This model could give an “empty box” error in case the 1% lethality
concentration was never reached. This issue has been solved.
· Toxic dispersion models: The toxic model now again allow to calculate a contour for a specific toxic
dose level. This allows to illustrate dosage contours which are lower than the 1% lethality dose, for
instance a dose equivalent for AEGL2-during 1800sec.

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EFFECTS version information 23
Version 10 release history

· Dispersion models: All dispersion models now allow to use non-standardised roughness length values.
Previous version would always require to enter a roughness class type, which was associated with a
specific Z0 value. These types now include a “user defined” choice, allowing to enter a specific
roughness length Z0 value.
· Outflow models: the choice for “Use representative step” now include choices “maximum flowrate”, and
“Third 20% average (mean)”, where outflow duration and specific outflow conditions are calculated
accordingly.
· Explosions models: The explosion models would use a lower cut-off value of 3500 Pa, which disabled the
possibility to draw overpressure contours for lower values. This cut-off has been reduced to 300 Pa,
which is the minimum value to obtain any relevant damage.

EFFECTS 10.1.0 (June 2017) Version Info

· User interface: contour levels and thresholds are now centrally set in “Presentation settings”: they apply
to all available models within the project:

As a consequence, the parameters that specified the contours for individual fire, explosion or dispersion
models in version 10.0.6 have become obsolete.
User defined concentration thresholds can still be defined in the dispersion “concentration” model.
· User interface: in “Reports” the dimensions of calculated contours will be reported as: maximum
distance, minimum distance (offset), maximum width and distance to the maximum width. Note that the
previously reported “contour length” corresponds to the new “maximum distance” minus “minimum
distance (offset)”.
· Dense gas dispersion: a wide range of changes have been applied to the dense gas models. A special
document is available for more information. Summarised the changes are:
· Instantaneous releases are now modelled as an initial cylinder instead of a half-sphere, where users can
define the initial area. If this area is entered as zero (default), the model will assume a cylinder with
height equal to diameter. Because the initial column height determines the initial spreading forces, users
can now adapt the behaviour to the real world storage situation.
· Semi continuous releases now have an improved transition behaviour at the end of the outflow. Previous
inconsistent discontinuity behaviour has been removed.
· The initial concentration internally calculated in vol% is now translated into density based concentration
[mg/m3] using the actual vapour temperature.
· Dense gas dispersion The model now reports a side view of the cloud as a graph (plume shape),
illustrating the potential vertical descending or rising behaviour. This is a qualitative representation: the

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EFFECTS version information 24
Version 10 release history

plume axis is shown, as well as the extend of the cloud (not configurable).

§ Fire models: when applying the choice “Include protection factor clothing” the model now also takes into
account that above a certain heat dose, clothing will be set on fire, leading to 100% lethality. This
“clothing burning distance” is reported.
§ Explosion models: now include a lethality calculation. This translation to lethality can be based on two
thresholds (inside glass damage & outside/inside total destruction level), based on pressure probits, or
use a user definable peak pressure-lethality relation.

EFFECTS 10.0.6 (November 2016) Version Info

· Combined models Liquefied gas: When adding pool evaporation source to a spray release rate and using
neutral gas, the initial dimensions will now be calculated based upon 100vol% concentration. In previous
versions a pre-dilution could occur, leading to smaller effect distances.
· Combined model for instantaneous release of pure gas: The pressure input field can also be set for
substances below critical temperature. For sub-critical temperature substances, the pressure can be set
by selecting “actual pressure” instead of the suggested “vapour pressure”.
· Liquid release model: In case of an unknown liquid viscosity of a substance, the model would raise an
unhandled error. This situation is now handled properly.
· Jet fire model: A jet fire can now be modelled as a “grounded jet”. If the release height is set below zero,
a situation of a “jet fire inside a crater” is now assumed. Due to impingement effects, these jet fires do
not have any lift–off so they are now modelled as a typical “grounded jet” (fire frustum shape starting at
ground level).

EFFECTS 10.0.5 (June 2016) Version Info

· User interface: saving of lethality grids: When saving calculated grids from the maps view page, the
resulting exported file could end up mirrored on Y-axis. This issue has been fixed.
· User interface: exporting graphs: several fixes in the exporting of graph data.
· User interface: combined models input screen behaviour: For combined models the choice for an outflow
type “Fixed flowrate” would disable some vessel property input boxes. Unfortunately these inputs were
not re-enabled when changing back to “Release from vessel” or “Release from vessel through pipe”. This
unintended behaviour has been fixed. Furthermore the enabling of “vessel length/height” input box while
using a spherical vessel was avoided.
· User interface: The ruler has been extended with the functionality to measure an area and the length of a
path. This could for instance be used to determine the area for pool evaporation.
Select the ruler button in the maps view and select the desired functionality. Reselect the option or press
ESC to end measuring.

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EFFECTS version information 25
Version 10 release history

· Mixtures: A calculation issue within the calculation of the burning mass flux for a mixture containing a
non-flammable component has been resolved.
· Various performance improvements in the loading of a project and adding models to a project.

EFFECTS 10.0.4 (April 2016) Version Info

· Pool evaporation model: The functionality to draw a polygonal shaped pool as evaporation source has
been withdrawn. The pool shape drawn could be located far away from the equipment release location,
leading to misplaced dispersion results when based on pool evaporation source.

EFFECTS 10.0.3 (April 2016) Version Info

· User interface, general behaviour: The functionality to open EFFECTS with an associated file by double-
clicking on an EFFX project file has been re-established.
· User interface, copy protection system: If the information from the copy protection dongle indicates that
the user has 30 days or less as a remaining license time, a warning will be displayed upon the start of
EFFECTS.
· User interface, projection systems: The default coordinate projection to use can now be set in
“presentation settings” (Menu “Edit..Options”). This allows the user to always start with a local preferred
system instead of the previous defaulted Pseudo Mercator system.
· Dispersion models: A potential unlinking of the “threshold concentration” input fields in a set of linked
models has been abandoned. This unintended unlinking could occur upon a changing a chemical
substance, because the list of available predefined concentration would be refilled, potentially leading to
a conflicting existing threshold concentration choice.
· Pool fire model: The definition method for the burning mass flux of mixtures has been changed. This
important parameter for the pool fire model is either provided as a substance specific parameter in the
database, or if this value is not available, the Burgess formula will be used to calculate a burning mass
flux. In case of mixture’s the same method is now provided for subcomponents and the mixture itself.
The user can provide a mixture specific value, or it is calculated using ideal mixing rule using the
components specific burning mass fluxes, which are potentially also being calculated.
Furthermore, many predefined example mixtures now have their typical values provided in the database,
according to the original publication of Rew & Hulbert (see model documentation). If the database value is
not provided, feedback will be given on the calculated burning mass flux.

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EFFECTS version information 26
Version 10 release history

· BLEVE Fireball model: The burst pressure input value is now a simple mode input value, and always
visible. This has been adapted because this input determines the hot or cold BLEVE fireball distinction
which should always be considered.
· Liquefied gas Vapour release: The two different models for vapour venting (Diers and “Simple vapour” )
have been combined into one ‘Liquefied gas vapour venting” model, which includes a user selection to
use either “Diers Top Venting” and “Simple Vapour outflow”. The default choice is the Diers Top venting,
which includes potential liquid droplets outflow due to bubbling effects.
· Liquefied gas two phase discharge (TPDIS) model: the behaviour of the model in case of a pure vapour
outflow has been improved. The result of the TPDIS model for a pure vapour outflow no closely
resembles the result of the simple vapour release model.
· Combined models Gas outflow: A potential error when applying the combined gas model with a fixed
flowrate has been eliminated. This error was raised by the “Turbulent Free Jet” model, because fixed
flowrate is no valid choice for this model.
· Spray release model: The rare occurrence of an error message “exit temperature lower than boiling
temperature” while the chemical is at saturated conditions has been fixed.
· Pool evaporation model: The pool evaporation model now includes the possibility to define the pool
evaporation area by drawing pool spreading boundaries on a map (polygon shaped pool). This area will
be used as a pool area limitation (maximum pool boundaries) implying that the representative pool may
actually become smaller. The resulting representative pool shape is added to the visualisation on the
map, also for the default circular pool.
In case of combined models with a pool evaporation AND pool fire model, the shape of a potential pool fire
can still deviate from the evaporation boundaries (rectangular or rim shape are not available as choices for
pool shape for evaporation).
· An issue has been resolved where selecting/deselecting models in the comparison set could lead to
errors.

EFFECTS 10.0.2 (February 2016) Version Info

· Dispersion models: both the neutral and dense gas model now report an outer contour of the
concentration threshold (user input choice). This contour illustrates the maximum distance to the
specified threshold concentration. This threshold will default be LFL in flammable cloud models, but can
be user defined and includes choices like IDLH, ERPG or AEGL concentrations.
A word of warning is required here when using these threshold for toxics, because although AEGL and
ERPG are concentration thresholds, they are associated to an exposure duration! For instantaneous and
short duration semi-continuous releases, the maximum distance to concentrations may be very large, but
has no meaning if exposure duration is not taken into account. It is strongly advised to use the
Mortality/Probit calculator from the EFFECTS tools menu to obtain the associated dose for the
corresponding exposure duration. Then use the toxic dose model to derive the contour for the calculated
associated dose.
· Toxic dispersion models: both neutral and dense gas now report a “Concentration versus time” graph at
reporting distance Xd. This graph clearly illustrates the relation between maximum concentration and
associated dose.
· Dispersion models: the step size refinement when searching for maximum concentration has been
improved, leading to a more accurate calculation and smoother graphs in the maximum region.
· Neutral gas toxic model: the calculation of the dose of a continuous source was corrected. As of version
10.0, this dose was calculated using an incorrect toxic exposure duration.
· Dense gas dispersion: a rare non convergence iteration situation that would lead to closing of the
application has been fixed.
· Pool fire model: the calculation of the burning mass flux for mixtures has been corrected. For single
components, many common substances already had an experimental value provided in the database
(expressed as kg/s.m2). If this value was not available, the Burgess relation (equation 6.67 of the Yellow
book) will be used to estimate the burning mass flux. This procedure could be inconclusive for mixtures
and has been improved. Note that as soon as a “burning mass flux” value is (user) defined in the
chemical database, this value will overrule the Burgess relation.

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EFFECTS version information 27
Version 10 release history

· Explosion region model: the calculation procedure to calculate worst case cloud overlap of a flammable
cloud with a congestion area has been improved, resulting in much faster and more accurate cloud
confinement results.
· Rupture of vessels: this model now uses “Vessel length or height” instead of L/D ratio, consistent with
outflow models. This will require recalculation and adaptation of inputs when loading this model from a
previous version.
· Liquefied Gas Instantaneous Release: the result parameter containing the “mass in the cloud” has been
renamed, now allowing to automatically link this result inside dispersion models. This change will require
a recalculation to see this results when loading from a previous version.
· User interface: the readout function of a displayed grid (e.g. heat radiation grid) now includes a unit
conversion and display of unit.
· User interface: the area calculation of user drawn receiver area’s has been corrected for projection
system conversions. This might influence the population density conversion for “vulnerable area” if local
projection systems (not using default WGS 84 Pseudo Mercator) were used.

EFFECTS 10.0.1 (November 2015) Version Info

· Rupture of vessels model: the parameter “Liberated energy” has been changed to “Liberated energy per
kg product” to avoid sensitivity to vessel mass contents. Furthermore, for BLEVE type of ruptures, this
parameter is no longer required as input but calculated for the substance using formula 7.2, 7.3 and 7.4
from Yellow Book paragraph 7.5.2. When using multiple fragments calculation, the maximum initial
speed is now limited to Moore relation (formula 7.15 YB), leading to potential bigger throwing range.
· BLEVE fireball model: the model now corrects temperatures for “hot” BLEVE situations. If the burst
pressure entered is higher than saturation pressure, this means that a “hot” BLEVE (tank heated up by
external fire) occurred, and the corresponding burst temperature will be calculated based on the failure
pressure. This implies that flash fraction and incorporated mass will be higher for a “hot” BLEVE. Burst
pressures equal or lower than saturation pressure are treated as cold BLEVE (external impact failure)
occurring at saturation pressure for initial temperature.
· Turbulent Free Jet model: the release type “fixed flowrate” was not applicable for this model and has
been removed.
· Vulnerable areas damages: For flash fires and toxic damages, the reporting of a dynamic cloud footprint
(required to calculate LFL overlap or inside lethality) is now forced. Apart from this, some issues with
finding the worst case wind direction were solved.
· Vulnerable areas and congestion areas can now also be compared in a comparison set.

EFFECTS 10 Release notes (Version 10.0.0 July 2015)

Effects 10 was revised in a large number of fields. First of all, the user interface was changed slightly, and
the project tree now contains multiple types of nodes, including a node for presentation settings,
background maps, receiving objects and comparison sets. The new project tree structure is described in
detail in the user manual.
EFFECTS now supports the use of multiple background maps and the use of coordinate projection
systems. Apart from background maps which can be loaded from files, background maps can be also
streamed from internet based tile servers.
The project file structure has been changed, its extension is now .EFFX, and it also incorporates the
background maps and any chemicals used within the calculation.
One of the biggest enhancements of EFFECTS 10 is its ability to work with chemical mixtures, including
the support for multiple database files (user defined or company specific databases). To be able to provide
these features, the chemical editor layout has been redesigned. Any “User-defined” chemicals that were
defined in version 8 or 9 can be converted into the new separate user database file.
Apart from the chemical database and support for mixture, EFFECTS vs 10 now allows to define "receiving
objects". These can be seen as geometrical shapes, or polygon areas, where an effect model can act
upon. Receiving objects can be either a “Vulnerable Area”, potentially to be connected to typical end
models reporting lethality, or a “Congestion area”, an area which can act as a congestion (or confinement)
area for explosive / flammable vapour. These congestion areas can be connected to Dispersion explosive
mass models (neutral and dense gas).

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EFFECTS version information 28
Version 10 release history

Many models inside EFFECTS 10 have been improved or revised in this version. Below is a list of the
important enhancements included:
· Outflow models: The spray release model now also contains a new "Statistical spray" method, which is
applicable for CO2 as well (which is a solid/gas equilibrium). Instead of using one typical droplet size,
this model uses a droplet size distribution, where rain-out fraction is highly dependent of these droplet
sizes and height of the release (falling height). The model can work with different number of samples,
influencing the calculation time and accuracy of the distribution. Compared to the original "Yellow book"
model, this model results in a higher approximation of the rainout fraction. The spray release model now
contains a selection box allowing to choose "Yellow book", "Aminal rule" or "Statistical spray method".
· The pool evaporation model will provide warnings when being applied with YAWS chemicals, because
the calculation of the Schmidt number uses critical volume which is highly unreliable when derived for
YAWS chemicals.
· Combined models outflow: All G3 "Leak" scenario now allows to use a "fixed flowrate" instead of a
calculated flowrate based on hole size and pressure. This option is available within Gas, Liquid, Liquefied
gas an Unified LOC combined models. When using this "fixed flowrate" selection, the model will
calculate a corresponding required exit pressure to obtain this flowrate. This exit pressure is often
required in many following calculations (like turbulent jet or spray release). This fixed flowrate can be
used in situations where release rate and hole size are given, such as a specific pumping rate.
· The BLEVE model was originally only used to calculate the fireball phenomenon, although a BLEVE
abbreviation itself refers to an explosion behaviour. The BLEVE fireball model can now also calculate
overpressure, which is based on "BLEVE blast" calculation method as published by van der Berg. (see
model references). The BLEVE blast calculation is also available as a separate explosion model.
· The BLEVE fireball model no longer uses a BLEVE mass as input, but asks for storage conditions like
vessel volume and temperature. Depending on these storage conditions a BLEVE mass incorporated
within the phenomenon will be calculated. This BLEVE mass is based on the generally accepted rule of
"3 times the adiabatic flash fraction". This is particularly important for (pressurized) LNG tanks, were
usage of the full vessel contents would lead to overestimation of the fireball phenomenon.
· All fire models will now report both heat radiation level contours and damage contours. Furthermore, a
heat radiation footprint can be presented for pool fire and jet fire.
· The pool fire model has been extended with a new "two zone pool fire" method, which is based on
original publication from Rew&Hulbert (see model references). Apart from this new calculation method,
separating the flame in a clear and a sooty part, the model will now calculate the view factor using a
"Discretised Radiation Method", which was already used for jet fires in version 9. Due to this extension
the pool fire can now have any shape: circular, rectangular, a rim or a user drawn polygon pool shape.
The specific burning rate, which was previously hard-coded for chemicals listed in the Yellow Book, is
now added as a chemical dependent property. The values that are listed here are taken from the more
recent Rew&Hulbert publication. If no data is provided, the Burgess relation is used to calculate the
burning rate.
· The Multi- Energy explosion model can now also use the GAME correlations ("Guidance on the
Application of Multi Energy", see model references) to estimate the blast strength. Instead of using a
fixed ME curve number, the max. overpressure will be calculated based congestion characteristics:
"Volume Blockage Ratio", average diameter of the obstacles, laminar burning velocity of the chemical
and flame path length. These substance dependent laminar burning velocities have been added to the
chemical database as a property.
· An explosion region model was added to allow the evaluation of explosive situation of a flammable cloud
captured inside a "congestion area". Such an area can be added as a receiver to a dispersion model
which reports a flammable cloud. The flame path length and incorporated mass can be calculated when
using a "congestion area" as a receiving object, applied to a flammable cloud dispersion model.
· The dispersion models have been extended with reporting of the dynamic concentration presentation, a
concentration footprint which presented on the map that can be drawn for any time step or be presented
as a moving cloud. The map view now allows to select this layer and once the concentration profile is
selected, offers a time slider that can also animate the moving cloud.
· The threshold concentration level to be used for contour presentations can now be taken from a list of
available thresholds in the database. Many common chemicals will have values like IDLH, AEGL and
ERPG values listed.

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Version 10 release history

· The "explosion dispersion" model have been renamed to "flammable cloud" and now also support
presentation of 50% LFL concentration contours.

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Version 10 release history

Version 9 release history

EFFECTS 9.0.23 (March 2015) Version Info

· Rupture of vessels: The parameter “Filling degree” was treated as a “relative liquid height” in case of
spherical vessels. This behaviour has been corrected, potentially leading to different results for spherical
vessels containing liquid (Cause of rupture=Pressurised Liquefied Gas Bleve).
· Dense gas calculation: In some unreproducible situations the TNO_Densegas model, which is an
external executable, could come up with a strange error message “TNO_DenseGas.exe - No Disk”.
The TNO_Densegas program has been adapted to avoid any sensitivity for detached external drives.

EFFECTS 9.0.22 (December 2015) Version Info

· Improved handling of changes in Windows regional settings.

· Spray release model: When using the “Aminal” method instead of the Yellow book method, the reported
liquid fraction was not corrected for rainout. The liquid fraction calculation for this situation has been
corrected.

EFFECTS 9.0.21 (December 2014) Version Info

· Toxic dispersion models: The calculation of the indoor toxic dose could result in an error when
performing toxic calculation on locations without a relevant concentration profile. This potential error has
been solved, now resulting in zero indoor dose for those situations.
· Turbulent Free jet: The width of the concentration contour is now also reported when a full concentration
contour is being calculated (concentration threshold reached within expansion zone).

EFFECTS 9.0.20 (October 2014) Version Info

· Outflow models for 10 minutes (fixed duration release): When applied for very small vessels, requiring
flow rates smaller than 1 kg/s the tolerance in finding the holesize would be taken too high which would
lead to inaccurate holesize calculation. This issue has been fixed.
· Poolfire model: When using very short outflow durations, the pool boundaries are not reached within the
outflow period. This could lead to the situation that a larger hole would lead to a smaller poolfire because
the timestep in calculating the poolradius was taken too big. This reported issue has been fixed in this
version.

EFFECTS 9.0.19 (May 2014) Version Info

· Latitude input: The combined models would disable the “Latitude” input field, if the solar heat radiation,
required for pool evaporation calculation, was manually added. Because this input is also required by the
Neutral gas dispersion model, this dispersion model would use a fixed default of 51 degrees (which is
the Dutch value). This behaviour is improved, and the dispersion model now uses the local environment
settings value.
· Pool fire model: When using the pool fire model with a semi-continuous release, the resulting pool
diameter is calculated based on an equilibrium between pool spreading due to the supply and the
burning rate occurring. When using longer duration of releases (hours), the time step for this calculation
would be taken too big, resulting in an overshoot and thus inaccurate pool diameter calculation. This
behaviour has been fixed.
· Unified LOC Combined models: The combination of the evaporation rate with a potential “air born” fraction
of the release would calculate the density based on pure vapour coming from the pool. For liquid
releases, this combination would result in a too high density, because the dilution above the pool was
not taken into account. In specific cases this would lead to the choice to use a “dense gas” dispersion
models whereas the dilution above the pool would already provide a “neutral” mixture. This behaviour did
not occur in the liquid LOC models, only in the unified LOC model, and for two phase releases, the

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EFFECTS version information 31
Version 9 release history

density would always result in “heavier than air” situation due to liquid droplets in the spray. The
calculation of the combined source density has been fixed, which may lead to slightly different results for
pure liquid situations in the unified LOC model.
· Liquefied gas combined models for instantaneous release: the potential occurrence of a BLEVE fireball
phenomenon was skipped if the material was toxic, to avoid a BLEVE fireball phenomenon being
calculated for a commonly used chemical like Ammonia. However, this would also eliminate a substance
like Ethylene Oxide from having a fireball phenomenon. This issue has been solved in this version, the
potential occurrence of a BLEVE fireball is now based on flammability limits criteria.
· Pool evaporation model: The so-called “Schmidt number” used in the main relation to determine the
evaporation flux, was calculated using thermal diffusivity, which was not according to the original theory
(formula 3.24 from Yellow Book, ref. Kawamura). This behaviour has been corrected, now using mass
diffusivity, calculated using the Fuller correlation (see model documentation). The calculated Schmidt
number, which is influenced by temperature, atmospheric pressure and typical air and chemical
properties, is now also listed in the results. Furthermore, the calculation of pool evaporation from water
for cryogenic liquids, released just below boiling point, will now be forced to a boiling situation. The LNG
evaporation from water has been fitted to the Burgess experiments and the film boiling heat transfer rate
has been corrected. These modifications might result in small changes (generally < 3%) in the
calculated evaporation rates

EFFECTS 9.0.18 (October 2013) Version Info

· Windows 8.1: This updated version of EFFECTS and RISKCURVES is now supported under Windows
8.1. The previous driver for the copy protection dongle has Windows 8.1 compatibility issues. This
version includes the latest version of this driver, which fully supports the Windows 8.1 operating system.
Users who want to move to Windows 8.1 must FIRST update the driver (by running our new setup) before
updating their OS. If you encounter problems uninstalling the old driver please contact the TNO
helpdesk
· Poolfire, Jetfire and BLEVE models: The maximum Surface Emissive Power (SEP) of the flame surface
will always be limited to 400 kW/m2, to avoid unrealistic high radiation fluxes (e.g in case of high
“fraction of heat radiated” values).
· Jetfire model; the atmospheric transmissivity is now calculated using the minimum distance to the flame
surface instead of the average distance. This will result in slightly higher radiation values but is more
realistic since the closest parts of the flame will contribute the most to the received radiation.
· Combined models: when combining toxic dispersion results from an instantaneous source with a
continuous source, the distance to a toxic threshold was taken from the graph, even if the graph was cut
off at an end distance Xd before the threshold was reached. These distances are now correctly
presented, according to the contours drawn.

EFFECTS 9.0.17 (September 2013) Version Info

· TNT model: The model now also accepts an explosion centre offset when the calculation is based on
TNT mass, enabling the possibility to use this calculation mode on vapour cloud explosions as well.
· Poolfire model: Some chemicals appeared to have a normal boiling point definition that deviated from the
exact temperature at which the vapour pressure is atmospheric pressure. For this reason, the phase-
check included in the poolfire model would conclude that the material is a vapour at its normal boiling
point and skip the calculation. This behaviour has been corrected, now using a tolerance on the
temperature, potentially providing a message that the pool temperature has been corrected.
· Neutral gas dispersion models: the minimum concentration averaging time allowed for (semi) continuous
releases, has been reduced from 20 seconds to 18.75 seconds, now exactly corresponding to a
minimum σy correction of 0.5 (YB par 4.5.3.4)

EFFECTS 9.0.16 (July 2013) Version Info

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EFFECTS version information 32
Version 9 release history

· User interface: The “Map” presentation now offers the possibility to read out values of presented grids,
such as concentration grids or lethality grids. Use the “crosshair” button and activate a grid layer to
present coordinates and corresponding grid value at the cursor position.
· User Interface: It is now possible to illustrate the “surrounding contours” of model results. In case of
phenomena that are directed by the wind, a surrounding circle around the release coordinate will be
drawn, illustrating the potential range of the effect.
· User Interface: Projects calculated with previous versions of the software will now show “out of date”
when opened in the newer version. Tip: to compare new/old results of a calculation session, do not
recalculate but instead copy the session and only recalculate that session (use “calculate from here”:
right-mouse click on session).
· The “Dynamic BLEVE” and “Static BLEVE” model have been integrated in one “BLEVE” model, with a
choice for the modeling approach to use. This implies that combined models (LoC scenarios) can now
also be used with the “Static” BLEVE approach.
· The “Spray Release” model now has the possibility to choose the “AMINAL approach” to calculate spray
fraction. The model documentation contains backgrounds of this alternative method.
· The “Turbulent Free Jet” model, used to calculate the expansion phase of a high pressure gas outflow,
now also reports offsets (X and Z direction), required to correct the starting point of the dispersion. This
implies that a dispersion model, linked to turbulent free jet, will use X and Z offsets as reported. As a
result, the linked model or combined model using a gas outflow and Turbulent Free jet can potentially
have a slightly increased consequence distance.
· A model chain using and outflow model, followed by a turbulent Free jet or Spray release, connected to
dispersion will now automatically transfer the release duration, calculated by the outflow model, to the
dispersion model.
· Explosive Dispersion Models: both neutral gas and dense gas now use the same “LEL concentration at
Tmac” parameter to illustrate results. This enables the possibility to compare results of neutral gas with
dense gas. Furthermore, the concentration versus distance graph is now reported at time T (user
defined) and no longer at Tmac (maximum area cloud) which could not be controlled by the user.
· The new Internet Explorer 10 versions appeared to be able to create a “Floating Point Error” when
creating the report table. This issue has been solved.
· The unit conversion on reported concentrations (mg/m3 to ppm’s etc) could result in wrong values when
multiple chemicals were selected. This issue has been solved.

EFFECTS 9.0.15 (March 2013) Version Info

· A version translation error in the combined LOC G1 model for liquids has been solved. Due to a change
in input parameters of the pool evaporation model (in version 9.014) the dispersion source type would get
misinterpreted when loading an older project. This issue, leading to potential large effect distances, has
been fixed. Loading an older project file containing a neutral dispersion model will now require re-entering
the “type of release” choice.
· User interface: Contours for user specified threshold levels (heat radiation, overpressure or percentage
damage) will now always have a legend description indicating the actual level presented. Comparison of
multiple models with different levels has been improved, now revealing level information.
· License system dongle driver: A new version of the copy protection dongle drivers has been included in
the setup. This driver version now also supports the MS Windows 8 ® operating system.
· Jet fire model: a jet fire that would touch a plane at receiver height could create strange heat radiation
curves and contours because heat load calculations cannot be performed “inside” the flame. This has
been solved by forcing a 100% lethality inside the jet fire frustum. Furthermore, the calculation of the
“maximum view factor” has been adapted, resulting in a more realistic view factor versus distance graph.
A description of the jet fire model improvements, with full backgrounds of the method and formula’s used,
has now been included in the installation folder.

EFFECTS 9.0.14 (February 2013) Version Info

· Educational licensing: Changes to support “educational” licensing. Educational licenses will be offered at
special conditions to non-commercial educational institutes only.

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Version 9 release history

· The Static BLEVE, Dynamic BLEVE and Jet fire models now support the use of a “height of the receiver”
input parameter, allowing to provide heat radiation footprints and damage results on various heights.
Because the default height is taken from “user defaults” and will probably be non-zero, recalculation of a
project might provide slightly different answers. Using a zero value of “receiver height” will still provide
identical results as with the previous versions.
· Pool evaporation model: The “Initial height of the pool” parameters has been removed from the pool
evaporation model, because these inputs created much confusion and didn’t provide additional benefits.
· Pool evaporation model: This model now uses either “Instantaneous” or “semi-continuous” release, and
this choice will no longer be forced into a linked dispersion model. Because even an instantaneous liquid
release into a pool will provide a semi-continuous vapour source for dispersion, previous version required
manual unlinking of the release type when connecting a (neutral) dispersion to a pool evaporation model.
Loading a pool evaporation model from older version will require to re-enter this “pool release type”.
· Turbulent Free Jet: An issue, where the turbulent free jet model would get a “changed after calculation”
status upon loading from file, has been fixed. This appeared to be happening if a the TFJ model was
linked to a release model using “release from pipe connected to vessel”.
· Turbulent Free Jet: This model now accepts pressure/temperature combinations corresponding to a
“Pressurized Liquefied Gas” situation. The model will use associated vapour properties to calculate the
outflow speed and expansion behavior.
· Multi-Energy model: The end distance (x-axis) for graphs created is now independent of the reporting
point Xd. Graphs will always be extended up to a distance where a minimum overpressure of 3500 Pa
(Minor damage value) is reached.
· Combined models: When using the Unified LOC scenario or Unified Release model, the situation of a
hole which is above the liquid level is now correctly treated as a vapour outflow, using the vapour release
model to calculate the release rate.
· User defaults: The user defaults for discharge coefficients and concentration averaging time, entered in
the “Options” ”Defaults” are now properly used inside the models. Previous version tend to use
hardcoded defaults, although they could be modified for every model.
· The catching of an potential situation where the SQL lite library was not found has been improved and
will now provide a clear message.

EFFECTS 9.0.13 (December 2012) Version Info

· The Unified release model will no longer display the parameter “vessel emptying time” for G1 or G3 Loss
of Containment events.
· The viewer for graphs now also allows adjusting of the x-axis unit.
· The help file has been adapted, it now provides more information about the location of user settings and
chemical database files.

EFFECTS 9.0.12 (November 2012) Version Info

· This update fixes a potential problem (introduced in vs 9.0.11) within the combined models where a toxic
model inside the model chain would not be updated with a modified chemical choice.
· The LOC Gas G1 (instantaneous) combined model will now always use the diameter of the expanded
cloud as the “width of the source (Y direction)”, thus avoiding required input for the scenario. Because
this may start the initial concentration at a lower value (UEL concentration for flammables) , this might
have a small influence on the maximum effect distance.

EFFECTS 9.0.11 (November 2012) Version Info

· The dense gas dispersion scenario would force a pool evaporation source to be set at the minimum of
normal boiling temperature and ambient temperature. As of this version, the temperature will now be
maximized to the normal boiling point and a warning will be provided if it is adjusted. (The release
temperature can thus still be sub-cooled or above ambient temperature.)

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Version 9 release history

· Within combined models, the single selection of a “local cloud fire” outcome now actually presents this
single phenomena.
· In G3 Leak LOC scenarios, it is now possible to use a maximum duration of the outflow, to be able to
include the interference of a blocking system.
· The behavior of the “Vessel emptying time” as used in G2 LOC scenarios (release of full inventory within
## minutes) has been improved. This parameter appeared to be enabled in G3 scenarios as well, where
it is not used.
· A fireball (Gas expansion) model is added to the fire models. It will calculate the footprint radius of an
expanded cloud in case of instantaneous gas release, assuming it has to be mixed up to UEL
concentration. This model was already included within the “unified release” model but can now also be
used separately.

EFFECTS 9.0.10 (September 2012) Version Info

· Two Phase Discharge model: The TPDIS model now also allows potential two phase outflow for
situations with a release from a hole in a pipe, where the hole size would be smaller than the pipe
diameter. Previous version would assume a liquid outflow, which was maximized to the two phase
release from the full diameter.
· Pool fire model: the pool fire model now also allow both the height of the receiver and the height of the
pool to be non-zero values. This implies that the pool fire can be elevated, even if the receiving plane is at
1.5 meter height.
· Within the combined LOC models, the maximum pool area, as used within the pool-evaporation model
was also used as the limiting area for the pool fire model. Unfortunately, if this value was empty,
because the pool evaporation was using “spreading without bunds”, the pool fire model would return an
error. This behavior has been corrected.
· The changing of the wind direction parameter in a linked model will now unlink the wind-angle input field,
thus making it possible to use linked models in different wind directions.

EFFECTS 9.0.9. (August 2012) Version Info

· Dense Gas Dispersion Toxic Dose model: When using a “Toxic Exposure Duration based on” choice for
“time limit of release” the exposure duration was not applied correctly. This would lead to an unrealistic
high lethality at longer distances because the release duration was not actually limited by the exposure
duration value provided by the user. This issue has been fixed.
· Toxic Dispersion Models: Both the “Neutral Gas ” and the “Dense Gas” toxic models will now also report
the maximum concentration versus distance graphs as available in the Dispersion concentration
models.
· Pool fire model: when using the “Unconfined fixed feed” choice, no limit was applied for the maximum
pool area size. The pool area is being calculated as the equilibrium situation were the input feed rate
would be equal to the burning rate. Since this might lead to huge pool areas, and this “Unconfined pool”
mode is also applied in the G2/G3 combined models, the G2/G3 continuous release scenario could not
be applied for “bunded” pool fire situations. In the updated model, the pool fire area can have also have an
upper limit for “unconfined fixed feed” pool fire situations. In the combined LOC models, this pool area
upper limit is copied from the pool evaporation input value.
· Chemical database editor: The temperature dependent “vapor pressure” graph was not shown for some
specific chemicals (e.g. Gasoline from YAWS). This behavior has been corrected.
· Jet fire model: The heat radiation from the top plane of the torch was overestimated due to a
simplification in the viewfactor calculation. This calculation has been improved, leading to more realistic
(lower) heat radiation values for situations were the top plane is visible and very close to the receiver.
· Jet fire model: The third heat radiation contour could be presented at the wrong location. This behavior
has been fixed.

EFFECTS 9.0.8. (June 2012) Version Info

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EFFECTS version information 35
Version 9 release history

· The Turbulent Free Jet model appeared to receive an “out of date” warning whenever a model switch was
applied. This behavior has been corrected.
· The Gas release from long pipeline (Wilson) model had an issue when trying to run a “hole in pipe”
calculation. This calculation has been corrected.
· The copy/paste behavior of an EFFECTS 9.0.7 model into previous EFFECTS versions or as a
RISKCURVES 9 scenario was unsatisfactory and has been improved.

EFFECTS 9.0.7. (May 2012) Version Info

· The EFFECTS project file is now a compressed (zipped) XML file, translation of older projects will be
done “one the fly”. The new educational version uses a non-exchangeable dedicated file format.
· When using a “pipe connected to the vessel” mode of the Two Phase Bottom Discharge model, the vapor
outflow calculation would use the pipeline diameter instead of the hole diameter. This behavior has been
corrected.

EFFECTS 9.0.6. (May 2012) Version Info

· The calculation of a liquid or pressurized liquefied gas from a spherical tank has been fixed and now
calculates without the need to provide a vessel radius.
· The copy / paste of models in the model tree without having the model tree selected could result in an
error. This has been fixed.
· The Turbulent Free Jet model has been moved from the “release models” menu tree to the “dispersion
models” menu item.
· The “Bleve (Static)”and “Dynamic Bleve” models will now adjust the maximum distance for the graphs, if
necessary, to obtain requested threshold values for effects or consequence distances. A correction was
applied in the dynamic model in the used atmospheric transmittance values.
· If a toxic model is run with a chemical that does not have toxic probits provided in the database, the
model will now give a more adequate warning.

EFFECTS 9.03 (March 2012) Version Info

User Interface
· The model list has been changed into a model tree, which illustrates the model hierarchy; the way
models have been linked. Sorting of the list has been added and based on alphabetical order of the
model descriptions.
· Linking of model is now achieved by a more intuitive “drag and drop” in this this model tree.
· The feedback on change of input has been improved. Models that require recalculation are now displayed
in italics in the model tree. Furthermore, a more explicit “out of date” warning is presented if results are
out of sync with inputs.
· The “Calculate” function now acts on the entire project but has intelligent behavior. The calculate button
will possibly trigger calculation of all models in the project, but it will only calculate those models that
have not yet been calculated or models that have been modified. Furthermore, if a changed model has
been linked to other models, it will also recalculate those attached models.
· Pressing <Alt> with calculate will force a complete recalculation of ALL models in the project.
· A specific sub selection of models in the model tree can be calculated by selecting this node in the tree
and using <Right mouse> “Calculate from here”
· The legend of the contour display Tab has been modified. The legend is now displayed on a separate
panel (which can be moved anywhere on the screen or docked to the right site). The panel now displays
the layers within this GIS display, allowing to change the order and activate de-activate layers. The
legend panel contains a popup menu that allows to activate/deactivate specific contours, change colors,
or allows saving of a specific layer.
· A “Probit converter” has been added to the tools menu, allowing to translate toxic probits into different
unit systems.

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EFFECTS version information 36
Version 9 release history

Model changes and improvements

· Dispersion models Toxic: The toxic dispersion model is now capable to perform a calculation of dose
and lethality inside, based on a ventilation rate.
· The Toxic dispersion models have the added possibility to define the method for applying a toxic
exposure duration: based upon time until sheltering, based upon time limit for passage of the cloud, or
based on a limit of the release duration.
· Dispersion models Explosive: The explosive calculation can perform a explosive mass calculation based
on mass between Upper Explosive Limits and Lower Explosive limits. This is now a user choice: either
mass above LEL or mass between UEL and LEL.
· The “gas” jetfire (Chamberlain) model has been adapted and is now suitable for use for two phase jet.
The “Cook” relations (see model documentation) have been added to correctly describe the dimensions
of a two-phase jet. Furthermore, the heat radiation footprint calculation is added. To be able to supply
this, the calculation of the viewfactor is no longer based on a cylindrical shape but is now based on the
real cone shape of the jet flame
· The Jetfire (Chamberlain) model was calculating flame dimensions based on the initial source rate (at
t=0). As of version 9 the Jetfire model uses calculated averaged source rate for the torch dimensions,
which may also come from a “long-pipeline” model.
· The poolfire model would also calculate a unconfined pool based on initial source rate, the model now
uses fixed flowrates as input, which can be calculated results from preceding outflow models.
· The G2 (outflow within 10 minutes) combined scenarios now allow to use other outflow duration periods
(other than 10min). This “outflow duration” is added as an expert parameter. (The G2 model calculates
the corresponding hole size to obtain this outflow duration.)
· All fire models have possibilities to modify heat radiation damage probits. Previous versions had
hardcoded values based on the Dutch Green book. These Green book values are now used as defaults
but can be altered.
· The liquefied gas from long pipeline (Morrow) model now also reports representative vapour fraction.
Furthermore all two phase release models will now report “vapour fraction” instead of the confusing “Void
fraction” or “Quality of outflow” parameter names.

Compatibility with version 8

· As of version 9.07, EFFECTS uses a compressed XML file structure, the internal XML format is the
same as version 8, with the exception of storage of “grids”(such as lethality and max concentration
footprint).
· Some models have additional input parameters in version 9 or may have modified input as compared to
previous version. EFFECTS will automatically translate input parameters, and may come up with some
empty parameters (displayed in red). Because the project file may be modified, the original EFFECTS 8
file will be saved as Effects.Backup file.

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EFFECTS version information 37
Version 9 release history

Version 8 release history

EFFECTS 8.1.7 Version Info

· Model “Conversion toxic probits from animal experiments”: Corrected behavior for using non SI units for
probits. An input parameter “chemical” has been added to be able to correctly translate input
concentration in ppm or volume% to mass based units.
· Fixed the behavior of switching a chemical using the chemical editor (browse button), which did not
perform a complete update of chemical related input fields.

EFFECTS 8.1.6 Version Info

· Poolfire model: Corrected the behavior that heat radiation contours appeared to be influenced by the
location.
· The menu item for damage models has been renamed from “consequence models” to “damage models”
· The “Distance from release Xd” input parameter now has a minimum value of 1 meter, to avoid problems
with dispersion models not calculating profiles and finding contours.

EFFECTS 8.1.5 Version Info

· Neutral / Heavy gas dispersion: When calculating concentration contours that occur very near to the
release point EFFECTS could become unresponsive. This has been corrected and proper contours are
presented now.

EFFECTS 8.1.4 Version Info

· Heavy gas explosive model: Under specific conditions the dense gas explosion model could not find a
LEL concentration contour or explosive mass, and only presented a message “steady state could not be
reached”. This has been adjusted and these cases now provide a LEL contour and explosive mass
information.
· Combination of sources for explosives: An overestimation of the LEL footprint of the combined sources
(instantaneous flash and pool evaporation source) occurring in the unified LOC scenario (two phase
instantaneous mode) or Liquefied gas LOC scenario G1 Instantaneous, has been corrected.

EFFECTS 8.1.3 Version Info

· Burst pressure field now always visible in Explosion, Rupture of Vessels model.
· Filter on chemical in Diers top venting model removed.
· The EFFECTS project converter (to translate version 7 .alf projects towards the version 8 .effects format)
was adapted to avoid calls to the old chemical database.

EFFECTS 8.1.2 Version Info

· Spray release model: The Representative Density has been corrected.

EFFECTS 8.1.1 Version Info

· Explosive Dispersion models: Version 8.1.0 appeared to be unable to find explosive (LEL) contours if a
non-zero release coordinate was entered. This is corrected.
· Dispersion models: In case of semi continues releases the concentration averaging time parameter is
now limited to the release duration. According to the Yellow Book (paragraph 4.5.3.4), for continues
neutral gas dispersion, the concentration averaging time cannot be shorter than 20 seconds. For

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EFFECTS version information 38
Version 8 release history

instantaneous dense gas dispersion, a concentration averaging time of zero is forced, according to the
SLAB manual.
· The two phase bottom discharge model no longer uses a corrected pressure ratio parameter (Car =1
formula 2.106 Yellow Book) for overpressure situations. For the dynamic vessel pressure, this would lead
to inconsistent behavior when applying small overpressure’s in the vessel.
· The Morrow long pipeline model is corrected for the use of (sub-cooled) ammonia.

EFFECTS 8.1.0 Version Info

· The modification in storage of chemicals and linked parameters requires a small change in the file
structure of EFFECTS. Translation of 8.0 towards 8.1 format is done automatically, in the background,
and is non destructive; the original 8.0 file remains untouched as effects.backup file. Note that EFFECTS
8.1 files cannot be opened in previous versions.
· Database
o The database file format has been changed. The database is now SQL based and it contains DIPPR,
YAWS and USER defined records in ONE table.
o With version 8.1, the DIPPR records are based on DIPPR release 2010, and chemicals can now have
multiple functions for multiple temperature ranges. (The use of DIPPR based chemicals still requires
an additional license.)
o If the user of previous EFFECTS 7 / 8.0 has created user defined chemicals, these added records can
be translated with the supplied “Chemicals convertor”.
o The Chemical database editor has been totally redesigned. It now also provides the graphs for
temperature dependent properties. The new editor can be accessed directly from the toolbar and the
chemical selection box and offers a convenient searching facility.
o The chemical parameter display now also contains the description for the source of the material:
YAWS, DIPPR or USER defined. Various calculations sessions of a model can use chemicals from
different sources, providing the possibility to compare results for different chemical property sources.
· User Interface
o The access to functions like “Probit calculator” “Mass/Volume calculator” has been moved to a new
menu “Tools”. This new menu also contains the tools “EFFECTS project converter” and “Chemicals
converter”. The listing of the model documentation has been moved from menu-item “View” to the
“Help” item. The use of shortcuts keys for “Save” and “Open” is now supported.
o The user configuration now also stores the user level “Simple, Normal or Expert”.
o EFFECTS no longer starts the calculation when <Enter> is pressed on a parameter input box.
o The first “0 km” tic was removed from the contours x/y-axis. This confused users because it gave the
impression that the scale was in kilometers.
o The export of contours as shape file now only takes current active contours.
· Models
o Dispersion concentration: the threshold concentration value is no longer overruled when < Default> is
pressed.
o Dispersion and outflow: Modification of user defined “Purple book representative rate”, “Concentrations
threshold” or “Concentration averaging time” parameters when re-opening the file is now abandoned.
o Dispersion concentration: The model would not always correctly identify whether or not the threshold
concentration is reached, preventing the contour to be found. This has been fixed.
o Combined “Loss of containment models”: concentration averaging time is now always 20 seconds for
flammable calculations, and 600 sec for toxic calculations.
o Combined “Loss of containment models”: for two phase instantaneous releases of flammable
substances, a Bleve phenomena can occur. Since we are confident that the Dynamic Bleve model
gives a more realistic modeling, the static model has been replaced with the dynamic Bleve model in
the combined LOC models.
o Two phase long pipeline (Morrow): The outflow rate is now based on single sided outflow. This is
altered because a possible linked spray-release model should have a consistent release rate/diameter
input. Furthermore the two phase model now works the same as the Gas (Wilson) long pipeline
model.

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EFFECTS version information 39
Version 8 release history

o Bleve: if the distance from release was too short, the models would still present the contours at this
max distance. This is solved, furthermore the model also reports the distances to radiation levels,
used in these contours.
o Poolfire: the model now reports the (non-circular) heat radiation or consequence contours based on
separate upwind, downwind and crosswind calculations.
o Pool evaporation: The temperature in the first iteration cannot exceed the boiling point anymore. The
heat supplied by the subsoil is now correctly calculated using equation 3.140 (instead of 3.120) for the
following subsoils: isolation concrete, light concrete, heavy concrete, clinkers, wood, carbon steel.
Note that this improvement implies that the heat supplied by the subsoil decreases with a factor 8 for
these subsoils! Pool evaporation now reports pool diameter (instead of pool radius) which can be
properly linked to a dispersion source width.
o TPDIS: The “total mass released versus time” graph would show a sudden increase to the total mass
released in some cases. This has been fixed.

EFFECTS 8 Release notes (Version 8.0.1)

· Gas Jet fire (Chamberlain): reported radiation level at distance Xd was corrected.
· Pool fire model: Improved calculation of view factor for receiver at height (see model documentation)
· Pool evaporation: enabling/disabling of “maximum pool surface” input field improved
· Liquefied gas spray release model: reported representative density now includes liquid droplets
· User interface: cleaning the project could result in one model remaining in project
· User interface: switching to Log panel view (when warnings were raised) is no longer activated when
switching (selecting/deselecting) models
· User Interface: behavior when comparing profiles graphs and contours improved, a comparison report
now includes case description

Model modifications in version 8.0

(contains all model modifications from version 7.6)
· Effects 8.0 contains a major revision of the user interface and the underlying model structure. As a result
of the modification of the file structure, EFFECTS 8 files cannot be read in older EFFECTS versions.
Note that EFFECTS 8.0 can read version 7 ALF files with the supplied project convertor. Older version 5
ALD files are no longer supported. They should be upgraded to version 7 ALF files with the previous
EFFECTS 7 version.
· Some default values (entered values when pressing <defaults> button) differ from earlier versions. This
will not affect calculations with values that are entered explicitly by the user.
· Combined models: An important choice had to be made for the "best applicable method" to combine two
dispersion sources. In the combined models for two phase releases, a direct release (either
instantaneous or from a spray release) and a secondary feed from material from the evaporating pool
may occur. For the combination of two continuous sources, this is pretty straightforward, but the
combination of instantaneous and continuous dispersion -which are two modes of operation for a
dispersion model- a realistic and practical method has been chosen. This method is described in detail
in the user manual.
· All release models (Gas, two phase outflow and liquids) now also have a "10 min release" version: These
models will search for a corresponding hole size for a 10 minutes scenario as used in the Purple Book.
These models will calculate the size of the hole, required to get an representative rate which equals the
flow required for the (G2) scenario in which the full inventory is released in 10 minutes.

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EFFECTS version information 40
Version 8 release history

Version 7 release history

EFFECTS 7.6.4 Version Info

· Multi Energy model: reported distance to overpressure threshold value was corrected.
· Liquid Thermal Conductivity can now be edited in YAWS chemical database.
· Bugfix for worldfile creator. Geo-referencing a background map with ruler could create error-message on
second attempt.

EFFECTS 7.6.3 Version Info

· Pool evaporation: a spreading pool without bunds will now report the appropriate end radius.
· Instantaneous flashing liquid: the final temperature of the vapor cloud is now corrected in case it is mixed
with ambient air until it reaches UEL concentration.
· Neutral gas dispersion: an analytic solution for semi continuous releases has been implemented,
resulting in faster and more accurate results, especially for short release durations.
· Neutral gas dispersion: improved accuracy (better error function); results of this improvement are mainly
noticeable close to the source.
· Heavy gas dispersion, explosive mass: Improved modeled behaviour of initial cloud (plume) above
evaporating pool. When working in the instantaneous mode, the model now also reports the upwind
contour in the contour graphs.
· All dispersion "explosion mode" models (heavy gas and neutral gas) now also report the LEL contour at
time tmac (Maximum Area Cloud). This is according to the "Free field method" as described in the
Purple book. For neutral gas, this LEL cloud footprint is calculated at height of release, the heavy gas
model uses ground level LEL footprint.

EFFECTS 7.6.2 Version Info

· The two phase jetfire model has been adapted to be able to work with an outflow angle in XZ plane.
· The pool fire model was adapted for the situation with a receiver on height. Yellow book formula 6.A.22
and formula 6.A.23 for viewfactor contained an error: minus sign should be plus-sign.

EFFECTS 7.6.1 Version Info

· A bugfix for the liquid release model was applied where pipelinelength was not read correctly.

EFFECTS 7.6.0 Version Info

· The Chamberlain Torch model has been adapted. First of all the gas-outflow model is run before
calculation of the flare, thus forcing consistent release rate/pressure/diameter combinations. The
calculation of the view factor/heat radiation now includes the radiation from the top of the flare. Default
soot fraction back to 0%. Contours in XZ plane are no longer reported.
· Neutral gas dispersion: Improvement in the coupling between Turbulent Free Jet and neutral gas
dispersion calculations. Furthermore, the concentration calculation is now based on the initial equivalent
gas density at the opening, resulting in lower concentrations. The consistency check on initial
dimensions of a neutral gas dispersion is improved. In neutral gas dispersion calculations, the wind
speed is now calculated at height of release (if height of release > 10 m). The neutral gas release
calculations have been fine-tuned for small release rate sources.
· Dense gas: Negative LEL offset values are now allowed.
· Turbulent Free Jet: reporting of jet width at limit of momentum region added. Calculation of initial jet
speed is now based on gas density at the opening instead of gas density in the vessel. Discharge
coefficient is now taken into account in the calculation of the equivalent diameter at the opening
· Pool evaporation model: added the use of a maximum temperature difference (on water). Energy balance
for situation continuous outflow on water has been improved.

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EFFECTS version information 41
Version 7 release history

· TPDIS model: Two Phase release now mentioned as “discharge” instead of “venting”. Correction for
depressurization for situation with applied overpressure vessel.
· When using the DIPPR database, the gas density was calculated using “non ideal gas” behavior, by
using the “Second Virial Coefficient” from the database. Unfortunately, this parameter is not provided for
all chemicals in the database, possibly resulting in an incomplete calculation. This behavior was fixed, if
no 2nd virial coefficient is known for a chemical, the program will use ideal gas relations.
· The behavior of loading and unloading database contents was improved, now avoiding time consuming
DIPPR database loading procedures, when switching between the various tabs.
· The copy protection dongles can now be remotely updated.
· User Interface: Possible error message when copying parameters to a new session is avoided now.
· The linking from pool-evaporation to dispersion models has been improved.

EFFECTS 7.5.2. Version Info

· Improvement of the SLAB dense gas model

· Behavior of Neutral Gas Toxic and Explosive Scenario’s (Riskcurves TLM) corrected.

EFFECTS 7.5.1 Version Info

· Bugfix of User Interface artifact: Some additional forms (Maximized graph view, System Parameters
Editor) provided errors during create.

EFFECTS 7.5.0 Version Info

Models:
· The Flashing Liquid instantaneous release model correctly handles chemicals with 100% adiabatic
flashing.
· The output of the Morrow model has been corrected for double sided outflow.
· Neutral gas dispersion:
Check for height of the release larger than height of mixing layer has been implemented: if the receiver is
above the mixing layer the concentration is set to zero
· The Pool Evaporation model for evaporation on land includes warning for pools that start boiling, the
possibility to select a surface roughness (determining minimum pool thickness) was added.
· The Pool Evaporation model for evaporation on water has been improved; the case that a liquid warms up
until it reaches its boiling point is now handled in an appropriate way
· The Pool Fire model now accepts pool sizes larger than 1500 m2
· More logical behavior of the TPDIS model concerning the end point for the calculations (empty vessel vs.
time chosen by user)
· The validity of the Turbulent Free Jet model has been extended to supercritical jets
Other:
· The resulting file size for project files is much smaller now
· Previously missing help items for new input fields have been added
· It is now possible to delete models from the model log
· A “most recently used files” list was added to the file-menu
· Automatic opening of the last file can now be disabled
· Several models now show their results in a more logical order; the most relevant graphs first
· Error message on missing help item no longer repeated unnecessarily
· YAWS Database values for Propane (LEL value) and Propene (validity range) were modified
· Support for the DIPPR 21 extended database was added. The extended DIPPR 21 chemical database
which contains over 1500 chemicals, can be separately licensed now. Please contact info.effects@tno.nl
for information on licensing.
As of 2019, this email address is no longer valid, support is continued at info.effects@gexcon.com (for
licensing information) and helpdesk support at helpdesk.effects@gexcon.com

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EFFECTS version information 42
Version 7 release history

· All combo-boxes now only accept values that are provided in the drop down list, thus avoiding errors
when typing non-existing choices.
· The FTP –update support was removed because of accessibility problems; updates are now distributed
through the HTTP website www.tno.nl\effects As of 2019, this URL address is no longer valid. Contact
address is www.gexcon.com/effects

Windows - VISTA compatibility was added. Although EFFECTS is not fully VISTA-compliant yet, there are
workarounds available to get EFFECTS running under Windows-VISTA.
o Writing in the application directory will be handled by Microsoft’s build-in virtualization mechanism.
o The help file format, provided with EFFECTS, is not supported in Windows Vista by default. To re-
enable the use of .HLP files within Windows Vista, users are advised to visit the official Microsoft
website http://support.microsoft.com/kb/917607 and download the available WinHlp32.exe program.
This will provide full support for the help files supplied with EFFECTS version 7.

EFFECTS 7.4.1. Version Info

· The Pool evaporation model now stops when an instantaneous release cools down below melting point.
· The reported “Total mass released at time T” in the MORROW model now actually reports at time T
instead of total mass released.
· The FTP update mechanism was modified to avoid update warnings because the file date of the FTP file
was newer than the EFFECTS file date.
· The setup procedure was improved, now providing automatic association of .ALF and .ALD project files
with EFFECTS.

EFFECTS 7.4.0 Version Info

· The Pool evaporation model has been completely reviewed and now correctly addresses minimum pool
thickness for both instantaneous and continuous releases. Furthermore, it will detect phase changes

the heat balance. For cryogens (e.g. LNG, LPG), relations for the heat supplied by various types of
subsoil are given in Yellow Book (3rd edition, §3.5.3). The pool evaporation model applies these relations
for chemicals, which boiling point is lower than 0 ºC. The model for instantaneous release “spreading in a
bund” replaces “instantaneous release” in a “bund”.
· The DIERS model now corrects for overpressure in the vessel.
· The calculation of outflow temperature in the TPDIS model was corrected.
· The choice for Pasquill or Monin-Obokhov has been re-established in various (dispersion) models.
· Turbulent Free Jet model now always includes outflow calculation to avoid non-consistent input.
· Spray release model now includes warning for non consistent input and correctly links to other outflow
models.
· All Link rules have been revised and are working properly now
· Rupture of vessel model is re-introduced in EFFECTS. Furthermore the fragment range calculation has
been improved.
· Bugfix for the TeeChart graph presenter were a saved contour shape did not contain Y values.
· Map backgrounds can now easily be removed from the graph tab.
· Models can now be removed from the model list (Ctrl-F4 or Del on model list).
· Some un-necessary input fields were removed from various models.
· The ordering in output result graphs has been revised to obtain “most important first”.
· Re-ordering of main-menu, avoiding number of sub-menu’s.
· Various issue’s in neutral gas dispersion have been fixed.
· Accidentally overwriting of old EFFECTS 5.5. ALD files is now avoided.
· Improvement of screen rules.
· The internet Update function has been improved. Note that it still requires a company policy which allows
FTP downloads.

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EFFECTS version information 43
Version 7 release history

· Saving of settings files etc in the application directory has been avoided, to enable running Effects as
restricted user. Full Windows-Vista © compatibility has not been archived yet, but will be provided in the
coming releases.
· The number of warnings on “Outside Database temperature limits” have been reduced.
· The number of screens presented when starting EFFECTS have been reduced.
· The setup procedure is now MSI based, allowing to distribute patches or performing maintenance tasks.
· The software now accepts multiple USB dongles, e.g. an EFFECTS and RISKCURVES dongle can be
combined.
· A number of issues with Slab have been fixed or addressed in release notes.

EFFECTS 7.3.2 Version Info

· The liquid outflow model locked up in an infinite loop when the user asked for the release rate at 0 s. This
is solved.
· When the button “Show International Chemical Safety Card on Internet (if present)...” was clicked in the
database editor, it resulted in a “file not found” error. This version is corrected and will now open a
corresponding browser window.
Workaround to correct this in previous releases: copy the file “dataconvertor.dta” which is available on the
website, to your database directory (e.g. c:\program files\TNO\Version7.3\EffectsGIS\Databases)

EFFECTS 7.3.1 Version Info

· The previous version referred to an outdated help file. This version will refer to the newest help file when
the F1 button is hit.
· When model Dense gas; instantaneous release; toxic dose of EFFECTS 5.5 (model 81) was converted
to the new EFFECTS 7 model Dense Gas Toxic, (model 201), the model will now set default to “perform
toxic calculation”.
· When an unknown fatal error occurs during startup, EFFECTS will delete its *.start file and standard
project file, and shut down. Deleting the *.start file will solve many potential problems like references to
erroneous files which might cause recurring startup problems.
· When a converted (EFFECTS 4 / 5.5) project was not saved under a different name, but saved as the
“standard project” file, a fatal error occurred after every second time EFFECTS was started. This is now
solved.
· For (very) small release rates, the neutral gas dispersion program could not calculate the explosive mass
vs. time graph and locked in an infinite loop.
· It was possible to switch between models during calculation of another model and during screen build of
the previous model. This has now been disabled.
· The Chamberlain (flare) model asked whether the outflow was “Choked” or “Unchoked”. This is not
needed anymore as the model itself now calculates whether a flow is choked or unchoked. It is reported
in the results section.
· Under certain circumstances, the pool of the evaporation model (instantaneous release) kept growing to
an unrealistic pool diameter in the case of a “semi-instantaneous” (e.g. 100,000 kg/s in 1 s) when
compared to an instantaneous release of 100,000 kg. This is now solved.

EFFECTS 7.3.0 Version Info

This version is the first commercial version that was released of version 7

· The user interface has been given the “look and feel” of other TNO software products;
· The geo-referencing of bitmaps has been simplified;
· A help function is now coupled to most input fields;
· The pool evaporation model has been completely renewed. The differences between models for boiling
and non-boiling liquids no longer exist. The model automatically determines the transition. The influence
of sunshine has now been better assessed;

Gexcon Netherlands B.V. Visiting address: helpdesk.effects@gexcon.com

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EFFECTS version information 44
Version 7 release history

· The model “non-stationary gas release from a long pipeline” has been added and is available in
EFFECTS 7.3;
· Non-stationary two-phase release from a long pipeline has been added and is available in EFFECTS 7.3;
· An advanced vapour outflow model has been added and replaces the older version;
· The known problems of the DIERS two-phase model (two phase top venting) have been solved in
EFFECTS 7.3;
· The champagne release model is no longer available in EFFECTS and has been replaced by the DIERS
model;
· The TPDIS model “Pressurized liquefied gas release from vessel or pipe” now applies to all substances
in the database. The older model replaced the two-phase outflow for substances which were not present
in the specific (internal) database of the model with a one-phase outflow;
· The TNT explosion model is present in version 7.3;
· The pool fire model can now also deal with differences in height between source and recipient (for
example for high tank fires ("tank top fires");
· The flare model (Chamberlain model) now itself decides whether a “choked” or “unchoked” flow occurs.
· The number of neutral gas dispersion models has been reduced from 9 to 3;
· The number of heavy gas dispersion models has also been reduced from 9 to 3;
· The dynamic BLEVE model is available in version 7.1 under the “additional models” menu. The standard
(static) BLEVE model is still available in the “Effect model” menu;
· All outflow models can now perform the calculation up to time t or when the installation is empty;
· The error log is easier to read with a multi-line view;
· The roughness length for dispersion calculations has increased from 6 to 8 categories. “Open water” is
one of the new categories. For a complete overview, see the EFFECTS manual.

Gexcon Netherlands B.V. Visiting address: helpdesk.effects@gexcon.com

Princenhofpark 18 Princenhofpark 18 w w w .gexcon.com
3972NG Driebergen-Rijsenburg 3972NG Driebergen-Rijsenburg
The Netherlands The Netherlands