Department of Chemical Engineering,

Aligarh Muslim University, Aligarh

CHC2922: Fluid Mechanics Lab

General Instructions:
1. Experiments will be conducted in groups of 3 to 4 students. The same group will
continue through out the course.
2. For every session of experiment, students are required to come to the laboratory
class prepared with the experimental procedure, the theory, the basic equations,
the observation tables, and the calculations etc. The associated teachers will
occasionally test the preparation and knowledge of the students.
3. Feel free to ask any doubts and questions to the teacher. For difficulties in
operation of the equipment ask the teachers and laboratory technical assistants.
4. Make a rough sketch of the experimental setup and note down on it all the needed
dimensions and information.
5. All observations and sketches are to be made only on A4 size sheets separately by
each student. Get the signature of anyone of the associated teachers on the
observation and sketch at the end of the class and attach them with the final
report. Observations should be complete with all required data, and information.
6. Each group should note at least two experimental runs duly verified by the teacher
during performance of the experiment. Failing which the observation sheet will be
considered as incomplete.
7. Report of the performed experiment is to be submitted positively on the next
practical turn by each student separately. Without submitting the previous reports,
students will not be allowed to perform any new experiment and shall be marked
absent on that turn.
8. At the end of semester, each student is required to compile all of his corrected and
updated reports in one file with proper indexing and submit at the time of his
viva-voce examination.
 GENERAL FORMAT OF THE REPORT TO BE SUBMITTED FOR EACH
EXPERIMENT

Page Size : A4

Cover Page : Should contain the following information:

No. and Name of :

the Lab.

Title of the Experiment :

Experiment No. :

Date of Conduction :

Date of Submission :

Submitted by :

Other Members:

1. ________________________ 2. _________________________

3. ________________________ 4. _________________________

5. ________________________

Group No. _________________

Contents of Report:

S. Headings Description
No.
1. Objective Mention the objectives of the experiment point wise.

2. Theory It should be brief and to the point. Detailed derivations should be

omitted. However, relevant reference may be given.

3 Description of the A short but otherwise complete description of the experimental

Experimental set up setup including all-important dimensions should be mentioned
along with a neat sketch of the experimental setup. The sketch
should be drawn with pencil only.

4. Experimental Describe experimental procedure point wise. Write them in past

Procedure tense

5. Sample Calculations Complete calculation of one run should be given. Each group
member should give sample calculations for separate runs.

6. Observations and Observations should be given in tabular form. Results should be

Results presented in tabular or graphical form. All the graphs should be
drawn with pencil or on Microsoft Excel only.

7. Discussion of the Discuss critically the results obtained. If the results show some
Results trend, discuss that also.

8. Conclusions Important conclusions drawn from the study should be

mentioned point wise.

9. Sources of Errors Errors in the experimentation should be identified and their

sources be discussed.

10. Suggestions Suggestions regarding the overall improvement of the

experimental setup/ measurements should be discussed briefly.
 Course Number and Title CHC 2922 Fluid Mechanics Lab.

Credits 1.5
Course Category Departmental Core (DC)
Pre-requisite(s) CHC 2030
Contact Hours (L-T-P) 0-0-3
Type of Course Laboratory Course
Course Assessment Sessional 60 Marks
End Semester Examination:
Viva-voce and/or Practical 40 Marks
Total 40 Marks
Grand Total 100 Marks

COURSE OBJECTIVES:

The course is designed so that the chemical engineering students get familiarized and become well versed with the various fluid
flow phenomena, and fluid flow measurement.

LIST OF PROBLEMS:

1. Flow through circular pipes

2. Flow through an annulus
3. Characteristics of flow through coils. (Helical and Spiral)
4. Reynolds Experiment
5. Verification of Bernoulli’s Theorem
6. Capillary flow viscometer.
7. Orifice meter and Venturimeter.
8. Velocity profile using Pitot tube
9. Efflux time of tanks
10. Characteristics of centrifugal pumps

Reference Books:

1. White , Frank M., Fluid Mechanics , McGraw Hill, 8th ed. (2017)
2. Brown, G.G., “Unit Operations”, CBS Publishers, New Delhi, 1995.
3. McCabe W.L., Smith J.C. and Harriott P., “Unit Operations of Chemical Engineering”, 7th Ed., McGraw Hill

Course Outcomes

After completing this course the students shall be able to:

1. Observe and understand the fluid-flow phenomena in chemical engineering systems, such as flow in a pipe,
annulus, coils, flow meters, pump operation & design.
2. Apply different concepts developed in fluid mechanics to analyze and handle any industrial fluid flow problem
associated with chemical processes.
3. Analyze and interpret experimental data in the light of fluid mechanics principles.
4. Prepare technical reports, learn to work as a team and develop technical communication skills.
Title of Experiment: Flow Through Straight Circular Tube.
Objectives:
a. To obtain a p vs Q plots.
b. To obtain f vs Re plot and compare it with standard plot.
c. To obtain the critical Reynolds number of flow.
Introduction:
Pipes and tubes are very convenient means, for transport of fluids with the aid of gravitational
head or suitable pumps and blowers. Knowledge of energy required for the fluid flow through
pipes is very useful to
a. Estimate the size of pumps or head required to obtained a flow rate in pipe system,
b. Estimate the maximum flow rate possible in a pipe system with a given pump/head.
c. Estimate the optimum size of pipe for a flow system, etc.
d. The energy requirement depends on the rate of flow, type of fluid, and size and roughness
of pipe wall.
Scope of the Experiment:
This experiment is aimed to train the students to take observations of the frictional pressure loss
in the pipe with the help of U-tube manometers and flow rate of the fluid in the pipe by directly
collecting volume of fluid for fixed times. They can observe that pressure loss varies with flow
rate and the way it varies and how their data can be analyzed further to predict critical Reynolds
number and to obtain standard plot. The pipes used are smooth stainless steel and rough
galvanized iron pipes and fluid used is water, a Newtonian fluid.
Theory:
When a Newtonian fluid flows in a steady state through a straight pipe, energy is dissipated in
overcoming the friction of the pipe wall. The energy dissipated-depends on the properties of
flowing fluid and the confining pipe and their relative motion. The significant properties of the
pipe are internal diameter, d , length, L , and the relative roughness,  / d , where  is the
average height of the projection of roughness inside the pipe, and the significant properties of
Newtonian fluids are their density, and viscosity  .
Thus, if we perform dimensional analysis the pressure loss for pipe flow p can be related to
cross-sectional average velocity as:
p   p  d , L ,  ,  , V 
=Kd a Lb  c  dV e
This leads to the relationship of the form:
y x
p  d   dV  
2   K 
2 V  L    
Where the left hand side term is called Fanning friction factor and denoted as f , and dV  / 
is termed as Reynolds number and denoted as Re . For laminar flow of Newtonian fluids, the
relation is theoretically obtainable as
 f  16 / Re
and is known as Hagen. Poiseuille law. For turbulent flow of newtonian fluids in smooth pipe,
the Blasius Resistance law:
f  0.0791 Re1/ 4
is a good approximation within the range 3000<Re<103. Colebrook's correlation,
1
 3.6 log  Re 7  5 103  Re  108
f
has larger range of applicability. For turbulent flow in rough pipes, Swamee and Jain correlation
is useful.
1   5.72 
 4 log   9 10-6   / d  102 ,5 103  Re  108
f  3.7 d Re 
Experimental Procedure:
1. Sketch and study the experimental set-up. Note the dimensions of the two straight pipes
(inside diameter and length between the two pressure taps) and specifications of the pump.
Also note the types of valves used, etc.
2. Fill the tank with fresh water, open the by pass line. See that the valves feeding the straight
pipes are closed. Switch on the pump/in the tank. Slowly open the needle valve feeding one
of the straight tube. Open the final outlet valve at the storage tank. Check that no where in the
straight tube and manometer air bubbles are present. If present, get the same removed. Wait
till the flow becomes steady as indicated by the level of manometric fluid in the two limbs of
the manometer. Note down the level of the two limbs. Collect sufficient volume of the water
discharging in the storage tank. Note down the time of the collection accurately. Open the
needle valve slowly to give a little higher flow rate. Repeat the measurement of pressure drop
and for different flow rates. Note down the temperature of the water.
3. Check that you have obtained enough reading in the laminar flow regime. Note that you are
required to obtain a log/log plot of f vs Re, and hence to insure that data points are spread
uniformly, take readings at smaller intervals at lower flow rates, but interval can be increased
as flow rate increases. Repeat the experiment for the other straight tube.
Calculation Procedure:
1. Convert the pressure drop and flow rate observations in N/m2 and m3/s units, respectively.
Note that pressure drop is given by
p    m   f  g  h1  h2 
where, m is the density of the manometric fluid,  f is the density of experimental fluid,
water in this case, and h1 and h2 are levels in the manometer limbs.
2. Plot these points on p , N/m2, and Q , m3/s graph and draw smooth curve to give variation
of pressure drop with flow rate for the two tubes, Now prepare a separate table by reading the
valves of p at different flow rates from this smooth curve. Calculate f from
  p   d 
f  2  
 2 V   L 
V  4Q /  d 2
Re  dV  / 
and obtain a log-log plot of f vs Re. Sudden break in the slope of this curve indicates the
change of flow regime from laminar to turbulent. Also plot the curves for the standard
correlation's for f vs Re and compare with your curve.
Discussion:
1. In books, f Vs Re is plotted on log-log graph. It is found that the roughness factor  / d
influences f only in the turbulent region  Re  4000  and not in laminar region
 Re  2100  . Explain why is it so?
2. In case of an oil (sp gr. = 0.9 and viscosity = 4.5mN.s will the plot of p vs Q coincide
with the curve for water? Give reasons for your answer.
References:
1. McCabe W.L., and Smith J.C., 'Unit Operations in Chemical Engineering'4th Ed. Mc
Graw Hill, Kogakusha (1985). 75-88, Fi.g 5-9.
2. Bird, Stewart and Lightfoot, 'Transport Phenomena', John Wiley and Sons Inc. (1960).
Title of Experiment: Flow Through An Annulus
Objectives:
a. To determine the pressure drop due to friction for flow of water through the annulus of
two concentric pipes and to obtain p Vs Q plot.
b. The calculate pressure drops using modified Fannings' equation and compare with the
experimental result.
Scope of the Experiment:
Double pipe heat exchangers are used in industries for heat interchange between a hot and a cold
fluid. There will be pressure drop due to friction as the fluid flow through the inner pipe and also
as the other fluid flows through the annulus.
Theory and Formula:
Fanning's equation is used to determine friction loss:
2
p 2 fLV
h fs  s 
g gD
where
h fs = skin friction loss, in meters of fluid
ps = Pressure loss due to skin friction (i.e. friction between fluid and pipe wall)
 = density of the fluid flowing inside the annulus or pipe.
f = fanning friction factor
L = length of flow, m
D = diameter, m
V = velocity of the fluid, m/s
In the case of straight pipes of circular cross section the inside diameter of the pipe is used in
calculating area of cross section and the friction losses whereas in case of non circular cross
section an equivalent Diameter, De is used. It is defined as four time the hydraulic radius rH
which is obtained by dividing the cross sectional area by wetted perimeter. The pressure drop
allowance in an exchanger is the static fluid pressure, which may be expended to drive the fluid
through the exchanger.
When a fluid flows in a conduit having other than a circular cross-section, such as an annulus, it
is convenient to express heat transfer coefficient and friction factor by the same types of equation
and curves used for pipes and tubes. To permit this type of representation for annulus heat
transfer, it has been found advantageous to employ an equivalent diameter De .
Cross Sectional area
De  4rH 
Wetted Perimeter
For circular pipe of diameter D

De  4  D 2 /  D  D
4
For a concentration pipe with inner pipe having outside diameter do and the outer pipe having an
 2
inside diameter Di , the annular area of cross section = ( D  d 2 ) and the wetted perimeter =
4 i o
4  / 4   Di2  d o2 
  Di  d o  De for annulus = 4rH    Di  d o  Fanning equation is modified by
  Di  d o 
substituting De for D .
Experimental Set-up:
Water from a constant level tank is pumped through the annulus of concentric pipe units. There
are two concentric pipe units of different annular space connected in parallel. Pressure taps are
provided at two points along with annular length for measuring pressure drop by a differential
type monometer using CCL4/Hg as the monometric fluid. The flow rate is controlled by needle
valve. After leaving the duct the water flows back into the tank.
Experimental Procedure:
Start the pump and adjust the flow rate with the needle valve. Start with minimum flow rate.
When steady state is reached, as indicated by levels in the two limbs of manometer, connected to
manometer taps, take the manometer readings and measure the time for collecting certain amount
of water leaving the duct. Repeat the experiment by gradually increasing the flow rate.
For each flow rate, take the reading of the mercury manometer for each annular arrangement.
Tabulate the Data as follows:
Concentric Pipe:
Unit 1:
I.D. of outer pipe Di1 =
O.D. of inner pipe d o1 =
Length of pipe L1 =
Unit 1:
I.D. of outer pipe Di 2 =
O.D. of inner pipe d o 2 =
Length of pipe L2 =

Calculations and Results:

1. Pressure drop due to flow in annulus 1
P1  h1   m   w  g
Pressure drop due to flow in annulus 2
P2  h2   m   w  g
2. Cross sectional area of annulus 1
A1   / 4  Di2  d o2  m2
 Velocity of water through annulus
V 1  Q / A1 m/s
De1  Di1  do1
Reynolds Number Re  De1V 1  / 
Pressue drop in cm of water
 LV 2 
h1   4 f1 1 1 100
 De1 

Where f1 is read from chart of f vs Re (Fig. 24 process heat transfer by D.Q. Kern)
Compare the calculated pr. Drop with experimentally obtained values.
Similar calculation is done for annulus 2.
Plot on the same graph, pressure drop due to friction, in cm of water, vs volumetric flow rate,
liter/s, for both units.
Questions:
Water is to be conveyed over a distance of 100m at the rate of 1 litre/sec. The outlet end of
the pipe should be 12.5 mm ID. Two alternative are proposed.
1. to have the pipe of the same diameter for the entire distance.
2. to have a pipe of inside diameter 25 cm for the first 50m and then 12.5 mm ID pipe for
the rest of the 50m.
What will be the ratio of pressure drop due to friction in the two cases?
References:
1. Kern, D.Q., 'Process Heat Transfer,' McGraw Hill Internet. Book Co.
2. McCabe and Smith, 'Unit Operations in Chemical Engg.', 4th Ed. McGraw Hall Book Co.
(1986).
3. Bird, Stewart and Lightfoot, 'Transport Phenomena', John Wiley and Sons Inc. (1960).
Title of Experiment: Capillary Flow Viscometer
Objective:
To determine whether a given fluid is Newtonian, if not, whether it follows the power law, if yes,
then to determine the values of o and n.
Scope of Experiment:
Most of the fluids of industrial importance such as thick solutions, slurries, oil, paints, emulsion,
polymers etc. do not posses a linear relationship between shear stress and the shear rate
developed within the fluid. Analysis of transport processes in such fluid thus requires a
knowledge of relationship between the shear stress and the shear rates. The experimental set-up
used here is helpful in determining the nature of fluid.
Theory:
Some of the non-Newtonian fluid follows the power law relationship between shear stress and
shear rate as given below:
dv
rz =  rz   z (1)
dr
n 1
dvz
where   0
dr
 rz = shear stress
dvz / dr = shear rate
 = non--Newtonian viscosity
0 and n = Parameter for power law fluid
If such fluid flows at a volumetric flow rate Q through a circular tube of diameter d and causes a
pressure difference of P between two points at a distance L then under fully developed laminar
and steady condition the following relationship can be obtained:
1/ n 1/ n
32Q  P d  4n  1 
    (2)
d3  4 L  3 n  1  0 
Thus for a power law fluid, a log-log plot of 32Q /  d 3 vs P d / 4 L will be a straight line. The
slope of the straight line gives the value of n , and 0 can obtained by its intercept on ordinate. If
value of n equals to 1, then the fluid will be a Newtonian fluid.
Experimental Set-up:
The experimental set-up consists of six capillaries of different lengths and diameters which
constitute 3 pairs of attached to the bottom of a tank vertically. Three different levels of water are
provided to create different pressure head in the capillaries.
Experimental Procedure:
1. Make a clean sketch of the set-up.
2. Keep all the capillaries closed and the value for the first constant level open.
3. Fill the tank and maintain a constant over flow.
 4. Open the capillaries one by one and measure the flow rate through each capillary.
5. Repeat the experiment for second and third constant level of water.
Observations and Calculations:
P can be calculated for each capillary flow and constant water level by P   gh
where h = hc  ht  hl
hc = height of the capillary
ht = height of the tank
hl = height of the liquid level from top of the tank
From plot Q vs P for each set of capillary obtain P at the same flow rate for both the
length. The difference of these pressure drops will give the actual pressure drop for the length of
the tube equal to the difference of the two lengths of the capillaries. From these data of Q vs P
plot a curve 32Q /  d 3 vs P d / 4 L on a log-log graph paper.
Results and Discussion:
1. Plot P vs Q for each set of capillary (3 plots)
2. Plot 32Q /  d 3 vs P d / 4 L on log-log graph paper (one plot)
3. Find the value of n and 0 from the plot in (2)
Answer the following questions:
a. Why two capillaries of two different lengths but same diameter are used in the set-up?
b. Derive the equation (2)
c. What are the sources of error in this experiment?
d. Name few Newtonian and non-Newtonian fluids.
Title of Experiment: Flow Through Helical Tube Coils
Objectives:
a. To obtain the coiling effect factor vs Reynolds number plot.
b. To obtain the critical Reynols number of flow for the given coil.
c. To compare the experimental data with the available correlations.
Introduction:
This experiment is just like the experiment on ‘Flow through straight tube’ and differs only in
that the tube is helically curved instead being straight. Due to curvature in the tube, the fluid
particle no longer flow parralel to the tube axis but flow in a pattern called ‘Double Helical
Flow’ or ‘Secondary Flow’. The important effects of the secondary flow in curved tubes as
compared to the straight tube flow are:
i. Changed frictional loss
ii. Changed critical Reynolds number
iii. Increased heat transfer coefficient and
iv. Decreased axial dispersion.
For the advantages of high degree of compactness (requirement of less space and weight) and
above mentioned transport characteristics, coils are extensively used as heat exchangers,
chemical reactors, precision, viscometers, blood oxygenators, etc.
Pipe bends, turns and helical coils fall in the category of constant curvature curved tubes,
whereas specially curved tubes coils have varying curvature. Flow through curved tubes, occurs
in a number of heat transfer applications. Usually such coils are immersed in a second fluid.
In curved tubes, the momentum of the fluid rounding the curve causes the velocity profile to be
distorted. The maximum velocity no longer occurs at the tube centre line but nearer the wall at
the outside of the coils bends. Visual studies have indicated the presence of secondary flow
patterns in which the fluid flows out-wart from the centre of the tube to the top of the bend and
then around the outside in a pair of loops. The secondary flow pattern, often called the double-
eddy or Dean effect, stabilizes laminar flow and increases the transition Reynolds number.
The effect of coil curvature is substantially greater in laminar flow than in turbulent flow. For
sufficiently large curvature and just before the transition, a given length of coiled pipe or tubing
may required five time the pressure drop of a straight length at the same flow rate. Thus the
correlation for curved tubes can be highly significant.
Scope of the Experiment:
The main aim of this experiment is to acquaint the students with the hydrodynamics of helical
coil tube flow. This will help in understanding the phenomena of increased pressure drop and
stability of flow.
Helical coils have constant curvature. As contrast to spiral coils, leaving only a small entrance
region, the velocity profile is fully developed. As found by earlier researchers, the flow in helical
coils is weakly characterized by a dimensionless number.
De  Rs d/D
Known as Dean number, named after Dean who was first to theoretically analysis flow in curved
tubes. Here d, is the inside diameter of he tube and D is the coil diameter.
Prandtl has given the following correlation for laminar flow.
P
C  f c / f s  c  0.37De 0.53
Ps
Where C is called coiling effect factor, which is the ratio of the pressure drop in the coil to the
pressure drop in the straight tube of the same diameter and length at the same flow rate. fc and
fs are fanning friction factor for the coiled and the corresponding straight tube.
Shaukat Ali (2001) has listed the various other available correlations for pressure drop in helical
coils, and from the analysis of their own data has arived at the following set correlations:
Eu  G rhc =38 Re-1 Re < Recritll
Eu  G rhc =5.25Re-2/3 Recritll < Re < Recritl
-1/3
Eu  G rhc =0.31Re Recritl < Re < Recritm
-1/8
Eu  G rhc =0.045Re Re> Recritm
Where Recritll , Recritl , and Recritm are critical Reynolds number for transition from low laminar to
laminar flow, critical Reynolds number for transition from laminar to mixed flow, and critical
Reynolds number for transition from the mixed to the turbulent flow, respectively, G rhc is the
 
geometrical number for regular helical coil flow given by d 0.85 Deq0.15 / Lc , d is the inside
diameter of the tube, Lc is the length of the coiled portion of the tube, Deq is the equivalent

 2

diameter of the coil defined by p 2 +  D  / , p is the distance between the two consecutive
turns of the coil and D is the diameter of the coil.
Thus there are three critical values of Reynolds number at which the helical coil flow changes
nature, and the flow has four requires of flow. The first regime is up to the first critical Reynolds
number, Recritll , and is termed as low laminar flow regime. The second regime lies between the
first critical Reynolds. Number and the second critical Reynolds number, Recritl , and is termed as
laminar flow regime. The third regime lies between the second critical Reynolds number and the
third critical Reynolds number, Recritm , and is termed as mixed flow regime. The fourth and last
regime is that of turbulent flow and lies beyond the third critical Reynolds number.
Experimental Procedure:
1. Sketch the experimental setup. Note down all the important dimensions mentioned on the
panel board. Measure the diameter of the tube by a traveling microscope.
2. Fill the tank with fresh water. Open the bypass line. See that the valves feeding the straight
and coil pipes are closed.
3. Start the pump. Note down the temperature of the water in the tank.
4. Slowly open one of the needle valve and the water outlet valve. Check that nowhere in the
line, there is air bubble present. If present, get the same removed.
5. Measure the flow rate and note the critical Reynolds number and check that you have
obtained enough readings in the laminar flow regime. For the measurements in the turbulent
flow regimes, note that you are required to obtained log-log plot between coiling effect factor
and Reynolds number, and hence to insure that data points are uniformly spread, take
readings at smaller intervals at lower flow rates, but interval can be increased at higher flow
rates.
6. Repeat the experiment for the straight tube.
Calculation Procedure:
1. Obtain smooth curves for pressure drop versus flow rate both for the straight tube and the
helical coil.
2. Note that helical coil has straight tube attached at its two ends. In order to get the pressure
drop for only the coiled portion of the coil, subtract from the total pressure drop in the
coil, the pressure drop in the straight tube portion as follows:
3. At a fixed flow rate, obtain the pressure drop in the straight tube ∆Pst. Calculate pressure drop
per unit lengths by dividing it by the length of the straight tube, Lst and then multiply by the
length of the straight tubes attached with the coil Lstc to get pressure drop in the straight tube
attached to the coil,
Pstc  Pst . Lstc / Lst
4. Subtract this form the pressure drop in the total coil, ∆Pct to get pressur drop in the helical
coil portion only ∆Pc at that fixed flow rate
Pc  Pct  Pstc
If the coiled length Lc is instead stretched to straight tube, then the pressure drop would be
instead,
Ps =Pst . Lc /Lst
5. Now calculate the coiling effect factor by
C  Pc / Ps
at that fixed flow rate.
6. Repeat the calculation at other flow rates and obtain a plot of log C vs log Re . Sudden break
in the slope of this curve indicates the change of flow regime from laminar flow to turbulent.
7. Also obtain log C vs log Re plot from the given correlations. Compare the experimental
values of Recrit and C from those predicted by the given correlations.
Reference:
1. Notes on ‘Flow through Curved Channels’, kept in the laboratory.
2. Goldstein, ‘Modern Development in Fluid Mechanics Vol. 1’, available in Seminar of
Mechanical Engg. Department.
3. Brodkey and Hershey, ‘Transport Phenomena a Unified Approach’ available in the
Departmental Seminar Library.
4. Shaukat Ali, ‘Pressure drop correlations for flow through regular helical coil tubes’ Fluid
Dynamics Research, 28, 295-310, 2001.
Title of Experiment: Flow Through Spiral Tube Coil
Objectives:
a. To obtain the coiling effect factor versus Reynolds number plot.
b. To obtain the critical Reynolds number for the given spiral coil.
c. To obtain the Eu  G . versus Re plot to verify the Shaukat and Shadhadri correlations.
Introduction:
This experiment is just like the experiment on 'Flow through Helical Tube Coil'. Unlike the
helical coil, spiral coil has varying curvature, maximum at the innermost turn and minimum at
the outermost turn. Due to this, the intensity of the secondary flow continuously decreases along
the tube axial direction from the innermost turn to the outermost turn.
Since the stability of coil flow depends on the intensity of the secondary flow, this is also
responsible for the presence of two critical Reynolds number of flow. One, when the turbulence
just appears at the outmost turn and secondly when the complete coil gets filled with turbulent
flow.
Spiral coil heat exchangers are particularly useful in situation where the available space is a
plane. These coils differ the way pitch, the distance between the consecutive turns of the coil
changes along with the length. Ali has classified them in the following well-defined
configurations:
1. Archimedean Spiral
2. Ascending Equiangular Spiral
3. Negative Logarithmic Spiral Coil
The Archimedean spiral coils have the property of constant pitch and the pitch of the ascending
equiangular increases while that of the negative logarithmic spiral decreases as the spiral recedes
away from the pole, the centre of the coil.
The polar equation of the Archimedean spiral curve which the axis of the tube of the
Archimedean spiral coil makes is given by
r  a
Where a  p / 2 and p is pitch, the d instance between consecutive turns a constant for the
Archimedean spiral coils. If Rmin and Rmax are the minimum and maximum radius of the coil, the
length of the Archimedean spiral is given by
Rmax 2
2 d 
Las   r    1dr
Rmin dr
 a   2  1 d

  R 2 
 Rmax  
2
a  Rmax  Rmax  max
 1    log e   1   
2 a  a   a  a  
  
   R 2 
 Rmax  
2
a  Rmax  Rmax  max
 1    log e   1   
2 a  a   a  a  
  

a  Rmin  R 2 
 Rmin  
2
 Rmin  min
 1    log e   1   
2 a  a   a  a  
  
Scope of the Experiment:
The aim of this experiment is to educate the students about the difference in
hydrodynamics of straight tube, constant curvature and varying curvature tube flows. It
will also help students to appreciate the procedure of the development of correlation
and verification of the developed correlations.
By performing the dimensional analysis
P  P V ,  ,  , d , Rmax , Rmin , p  it can be shown that the pressure drop across coil can
be correlated as
Eu.G as  a Reb


Where Eu =P/ 2 V 2  is the Euler number of flow and Gas is a geometrical number, a
combination of geometrical parameters for the Archimedean spiral coils.
Shaukat (2000) has obtained the following correlations, based on their experimental data:
Eu G as  230 Re0.9 for low laminar flow Re  800
Eu G as  46.52 Re 2 / 3 for laminar flow 800  Re  6300
Eu.G as  1.23 Re1/ 4 for mixed flow 6300  Re  10, 000
Eu.G as  0.78 Re 1/ 5 for turbulent flow Re > 10, 000
pd 1/ 2
Where Eu.G as 
( Rmax )3/ 4 ( Rmax  Rmin )3/ 4
The flow in an Archimedean spiral coil remains quite stable up to a Reynolds number of
800 called low laminar critical Reynolds number, the flow up to Reynolds number of
6300 remains laminar called laminar critical Reynolds number, above this Reynolds
number there will be mixed flow in the coil up to a Reynolds number of 10,000 called
mixed flow critical Reynolds number. Above this Reynolds number, the coil will be
fully filled with turbulent flow. Thus there are four regimes of flow. The first regime is
that of low laminar flow, the second regime is that of laminar flow, the third regime is
that of mixed flow, and the final and last regime is that of turbulent flow.
Experimental Procedure:
1. Sketch the experimental setup. Note down all the important dimensions mentioned on the
panel board. Measure the diameter of the tube by a traveling microscope.
2. Fill the tank with fresh water. Open the bypass line. See that the valves feeding the straight
and coil pipes are closed.
3. Start the pump. Note down the temperature of the water in the tank.
4. Slowly open one of the needle valve and the water outlet valve. Check that nowhere in the
line, there is air bubble present. If present, get the same removed.
5. Measure the flow rate and note the critical Reynolds number and check that you have
obtained enough readings in the laminar flow regime. For the measurements in the turbulent
flow regimes, note that you are required to obtained log-log plot between coiling effect factor
and Reynolds number, and hence to insure that data points are uniformly spread, take
readings at smaller intervals at lower flow rates, but interval can be increased at higher flow
rates.
6. Repeat the experiment for the straight tube.
Calculation Procedure:
1. Obtain smooth curves for pressure drop versus flow rate both for the straight tube and the
helical coil.
2. Note that helical coil has straight tube attached at its two ends. In order to get the pressure
drop for only the coiled portion of the coil, subtract from the total pressure drop in the
coil, the pressure drop in the straight tube portion as follows:
3. At a fixed flow rate, obtain the pressure drop in the straight tube ∆Pst. Calculate pressure
drop per unit lengths by dividing it by the length of the straight tube, Lst and then
multiply by the length of the straight tubes attached with the coil Lstc to get pressure drop
in the straight tube attached to the coil,
Pstc  Pst . Lstc / Lst
4. Substract this form the pressure drop in the total coil, ∆Pct to get pressur drop in the
helical coil portion only ∆Pc at that fixed flow rate
Pc  Pct  Pstc
If the coiled length Lc is instead stretched to straight tube, then the pressure drop would be
instead,
Ps =Pst . Lc /Lst
5. Now you get
C  Pc / Ps
at that fixed flow rate Repeat the calculation at other flow rates and obtain a plot of log C vs
log Re . Sudden break in the slope of this curve indicates the change of flow regime from
laminar flow to turbulent.
6. Also obtain log C vs log Re plot from the given correlations. Compare the experimental
values of Recrit and C from those predicted by the given correlations.
7. For this experiment, also verify the Shaukat correlations by plotting log  Eu.G as  vs
log Re obtained from the experimental data and those from the correlations.
8. Also note that for the determination of pitch, in this case, the outer diameter of the
tube is also to be determined.
Questions:
1. Perform the dimensional analysis suggested above.
2. Discuss the sources of error in the experiment.
Additional Reference:
1. Shaukat and Sheshadri, 'Pressure Drop in Archimedean Spiral Tubes', I and EC
Process Design and Development, 10(3), 328, 71.
2. Ali, S. 'Pressure Drop Performance of Coiled Tubes', Chem. Engg. Res. Des., 67,
428, 1989, Institution of Chemical Engineers, London.
3. Ali, S., 'Pressure drop characteristics of coiled tube flow, Proceedings of the
International Symposium on Recent Advances in Experimental Fluid Mechanics',
IIT, Kanpur, 2000.
Title of Experiment: Verification of Bernoulli's Theorem
Objective:
To investigate the validity of Bernoulli's theorem as applied to the flow of water in a
tube of varying cross section.
Theory:
When an inviscid incompressible fluid is flowing through a duct under steady state then
according to Bernoulli's theorem its total mechanical energy remain conserved. The
mechanical energy constitutes Kinetic energy, pressure energy and potential energy of
the fluid. If the fluid of density  is moving with cross-sectionally average velocity V
at an attitude Z and a pressure P then the total mechanical energy at a cross section per
unit volume of the fluid is given by (without friction loss and pump work).
1 2 1 2
1 V 1  P1   gz1   2 V 2  P2   gz2
2 2
Where a is the kinetic energy correction factor equal to      ds  /(V ) S
s
3 3
and S is

cross sectional area and V    ds  / S

Considering the balance between any two section of the duct 1 and 2, the Bernoulli's
theorem can be written as
1 2 1 2
1 V 1  P1   gz1   2 V 2  P2   gz2
2 2
For a horizontal setup z1 =z 2 and thus the above equation can be written as
2
V P
   constant
2g g
The above equation is known as Bernoulli's Equation. Each expression of the above
equation represents various heads. The first term is the velocity head and the second
term is the pressure head. The sum of these two heads equals to total head which
remains constant.
Experimental Setup:
The experimental setup consists of a tapering tube (test section) made of Perspex
to provide varying cross section. Pressure tapings are provided at various sections of
the tube to measure the pressure head. The two ends of the tube are provided with
union, which may be connected directly to the hydraulic bench and outlet to pass the
liquid through tube. A hypodermic with a pressure taping is also provided to measure
the total head at any cross section of the tube. An additional taping is provided to
facilitate setting up. All the pressure tapings are connected to a bank of pressurized
manometer tubes. Pressurization of manometer tube is facilitated by the coupling it to a
hand pump, provided with the setup. The outlet of the tube is provided with a control
valve, which is used to regulate the flow rate of liquid through the tube. The whole
apparatus is kept and attached to a hydraulic bench which is provided with the pump
etc. to cause a flow through tube.
Experimental Procedure:
1. Make a clean sketch of the setup and note on it the dimensions of various
sections.
2. Level the apparatus on hydraulic bench using the adjustable screws.
3. Fill the apparatus manometer tube with liquid to discharge all pocket of air from
the system and ensure all connecting pipe are free from air.
a. Conversion flow.
b. Divergent flow.
4. Adjust the inlet feed and flow control valve to combine the flow rate and system
pressure in order to get the highest and lowest manometer level. Use hand pump
at the air inlet to raise the air pressure above the liquid columns.
5. Measure the flow rate and reading of each manometer tube.
6. Insert the hypodermic probe to the end parallel position of duct and move it into
tapered portion 1cm at a time and note its distance from parallel portion. Also
note the reading of the manometer tube attached to it.
7. Repeat from step 5 for different flow rates.
8. Stop the feed, drain off the apparatus, withdraw the probe fully, undo the
coupling, reverse the test section and replace the coupling.
9. Repeat from Step 2.
Observations and Calculations:
Flow rate can e computed by collecting a volume of liquid from tube for a known time.
The velocity at any cross section can be determined by dividing the flow rate by its
cross section area. The pressure head can directly read from manometer readings. For
calculations of total head plot a curve total head vs probe position. Obtain total head at
various positions from this graph.
Results and Discussion:
1. Find velocity head and pressure head for each cross section. Check whether the
summation of these two heads is constant, if not, why?
2. Check whether the summation of the two heads is equal to the total head measure
by the probe-manometer, if not, explain the reasons.
3. Comment on the validity of Bernoulli's equation for the system tested.
4. Established the mathematical form of Bernoulli's theorem by applying a
mechanical energy balance between any two sections of the tube.
Zakir Husain college of Engineering & Technology

Characteristics of Centrifugal Pump

OBJECTIVE:
To study the characteristics of centrifugal pump in series and parallel mode.

THEORY:
The Hydraulic machines, which convert the mechanical energy into hydraulic
energy, are called pumps. The hydraulic energy is in the form of pressure
energy. If the mechanical energy is converted into pressure energy by means of
centrifugal force acting on the fluid, the hydraulic machine is called centrifugal
pump.
The flow in centrifugal pump works on the principle of forced vortex flow, which
means that when an external torque rotates a certain mass of liquid, the rise
in pressure head of the rotating liquid takes place. The rise in pressure head
at any point of the rotating liquid is proportional to the square of tangential
v2 ω 2 r2
velocity of (i.e. rise in pressure head= 2g or 2g ) the liquid at that point. Thus
at the outlet of the impeller where radius is more, the rise in pressure head will
be more and the liquid will be discharged at the outlet with a high pressure
head. Due to this high pressure head, the liquid can be lifted to a high level.
Centrifugal pump is a mechanical device, which consists of a body, impeller
and a rotating mean i.e. motor, engine etc. Impeller rotates in a stationary
body and sucks the fluid through its axes and delivers through its periphery.
Impeller has an inlet angle, outlet angle and peripheral speed, which affect the
head and discharge. Impeller is rotated by motor or I.C. engine or any other
device.
Multistage Centrifugal Pump: A centrifugal pump consisting of two or
more impellers; the pump is called a multistage centrifugal pump. A multistage
pump is having the following two important functions:

• To produce a high head.

• To discharge a large quantity of liquid.

If a high head is to be developed, the impellers are connected in series while for

Fluid Mechanics Lab, December 2010 1 Chemical Engineering

Zakir Husain college of Engineering & Technology

discharging large quantity of liquid; the impellers are connected in parallel.

P 3600
Power input can be calculated by, Ei = P
× EM C , kW
Shaft output is, ES = Ei × ηm , kW
R1 −R2
Level of liquid collected in tank is, R = 100 ,m
using the value of A and R and time of rise in liquid level ’t’ the discharge from
A×R
the pump can be calculated as, Q = t , m3 /sec
ρ×g×Q×H
Therefore the pump output can be calculated as, E0 = 1000 , kW
H = Hd + HS + Hpg , m of water
where, For Single Stage, HS = HS1 , m of water
HS1 +HS2
For Two Stage Parallel Arrangement, HS = 2 , m of water
For Two Stage Series Arrangement, HS = HS1 + HS2 , m of water
where Hd , HS , HS1 , HS2 are the measured pressure Pd , PS , PS1 , PS2 respectively
in m of water.
Various efficiency can be obtained as
E0
η0 = Ei × 100%
ηP = EES0 × 100%

For the above three arrangements of pump, determine Power Input, Shaft Out-
put, Discharge, Total Head, Pump Output, Overall Efficiency, and Pump Effi-
ciency. Plot the performance characteristics curve for Head vs Discharge, Speed
vs Discharge, and Pump Efficiency vs Discharge.

NOMENCLATURE:
A = Area of measuring tank, m2 .
EM C = Energy Meter Constant, Pulses/kWhr.
Ei = Power input, kW.
ES = Shaft output, kW.
E0 = Pump output, kW.
g = Acceleration due to gravity, m/sec2 .
H = Total Head, m.
Hρg = Height of pressure gauge from suction of the pump, m.

Fluid Mechanics Lab, December 2010 2 Chemical Engineering

Zakir Husain college of Engineering & Technology

N = Speed of Pump, RPM.

P = Pulses of energy meter.
Pd = Delivery pressure, kg/cm2 .
PS1 = Suction pressure of pump 1, mmHg.
PS2 = Suction pressure of pump 2, mmHg, kg/cm2 .
Q = Discharge, m3 /sec.
R = Rise of water level in measuring tank, m.
R1 = Final level of water in measuring tank, cm.
R2 = Initial level of water in measuring tank, cm.
t = Time taken for rise of water level in measuring tank (R), sec.
tP = Time taken for P pulses of energy meter, sec.
ρ = Density of fluid. kg/m3 .
ηP = Pump eficiency, %.
η0 = Overall eficiency, %.
ηm = Motor eficiency, %.

DESCRIPTION:
The present Centrifugal Pump Test Rig is a self-contained unit operated on
closed circuit basis containing a sump tank. The set-up consists of two Cen-
trifugal pumps. Both pumps are coupled with individual DC Motors. Power
input to these motors is varied by means of Thyristor controlled DC Drives to
vary the RPM of motor. Two RPM indicators with Proximity sensors indi-
cates the RPM of each pump separately. Flow of water is measured by using
measuring tank and stop watch. Vacuum gauges are fitted on suction line and
pressure gauges are fitted on delivery line of each pump to measure the pressure.

EXPERIMENTAL PROCEDURE:

1. Clean the apparatus and make all Tanks free from Dust.

2. Close the drain valves provided.

Fluid Mechanics Lab, December 2010 3 Chemical Engineering

Zakir Husain college of Engineering & Technology

3
3. Fill sump tank 4 with clean water and ensure that no foreign particles are
there.

4. Open Flow Control Valve given on the water discharge line and Control
valve given on suction line.

5. Ensure that all On/Off Switches given on the panel are at OFF position.

6. Now switch on the main power supply(220 V AC, 50 Hz) and switch on
the pump.

7. Set the desired RPM of motor/pump.

8. Operate the Flow Control Valve to regulate the flow of water discharged
by the pump.

9. Operate the Control Valve to regulate the suction of the pump.

10. Record Discharge pressure and Suction pressure.

11. Record the Power consumption and Discharge.

12. Repeat the same procedure for different speeds of pump.

13. Repeat the same procedure for different discharge with constant speed.

14. Repeat the above procedure for Series and Parallel combination of Pump.

15. When experiment is over, gate valve provided on the discharge line is to
be properly opened.

16. Reduce the RPM of the pump with the help of DC Drive.

17. Switch OFF the pump first.

18. Switch OFF Power Supply to Panel.

Fluid Mechanics Lab, December 2010 4 Chemical Engineering

Zakir Husain college of Engineering & Technology

OBSERVATION TABLE:
1: Centrifugal Pump (Single Stage)

S.No. N1 , PS1 , Pd , R1 , cm R2 , t, P tP ,
RPM mmHg kg/cm2 cm sec sec
1.
2.
3.
Note: For Two Stages - Series and Parallel Setup add columns for readings of N2 and PS2

Data:
EM C = 3200 pulses/kWhr
A = 0.252 m2
Hρg = 1 m
ηm = 0.8 (assumed)

PRECAUTIONS & MAINTENANCE INSTRUCTIONS:

1. Never run the apparatus if power supply is less than 180 volts and above
230 volts.

2. Never fully close the delivery line and By-Pass line Valves simultaneously.

3. Always keep apparatus free from dust.

4. Always use clean water.

5. If Apparatus will not be in use for more than half month, drain the appa-
ratus completely.

TROUBLESHOOTING:

1. If pump does not lift the water, open the air vent provided on the pump
to remove the air from pump.

2. If still water is not lifting, the revolution of the DC motor may be reversed.
Change the electric connection of the motor to change the revolutions.

3. If panel is not showing input, check the fuse and main supply.

Fluid Mechanics Lab, December 2010 5 Chemical Engineering

Zakir Husain college of Engineering & Technology

4. If field failure (FF) indicates on the control panel and the motor is not
moving, check the fuses if burnt, change it.

5. If overload (OL) indicates on the panel and motor stops moving, reduce
the load.

6. If RPM indicator is not displaying the RPM, check the distance of prox-
imity switch and adjust it to 2-3 mm.

REFERENCES:

1. R.S. Khurmi,”Hydraulics, Fluid Mechanics and Hydraulic Machines”, 11th

edition., S.Chand and Company LTD., 2008, page 582-585,587,590.

2. P.N. Modi and S.M. Seth,”Hydraulics and Fluid mechanics”,15th ed. Stan-
dard Book House, 2005, page 1081-1083.

Fluid Mechanics Lab, December 2010 6 Chemical Engineering

 2
= __________________(1)
Where, = mass (Kg)
G= Acceleration of gravity (m/sec2)
= Velocity of Particle (m/sec)
D= Diameter of Trommel (m)
= __________________(2)
60
N= Number of Trommel revolutions/minute.
Put the value of equation (2) in equation (1), we get:
2
= _________________(3)
60
60
= _________________(4)
2
Separation Efficiency is calculated as:
ℎ
= × 100
ℎ
The best operation speed is usually 0.33 to 0.45 times of the critical speed.
Experimental Procedure:
1. Prepare the feed mixture of three different sizes.
2. Note down the size of the desired material.
3. Switch ON the power supply.
4. Start the Trommel and also set the RPM.
5. Start pouring the feed slowly into the hopper.
6. Place the receiver at the outlet.
7. Repeat the experiment for different RPM.
8. Repeat the experiment for different angle of inclination.
9. When experiment is over, switch OFF the power supply.
Observations:
Feed size: ...................
Size of desired material: .........
N = …….....................RPM
D = ………..............m
WF =………..........kg
Mesh No. Mass retained(gm) Mass retained(gm) Mass retained(gm)
Screen1 Screen2 Screen3
 Wt of desired Wp1 =....... gm Wp2 =.......gm Wp3 =.......gm
material in pdt

Calculations:
= × 100%
Nomenclature:

Nom Column Heading Units Type

D Diameter of particle of desired material m Measured
N Number of revolutions of trommel per minute RPM Measured
S Separation efficiency % Calculated
WF Weight of desired material in feed Kg Measured
WP Weight of desired material in product Kg Measured
ϴ Angle of inclination of Trommel with horizontal degree Measured
 ~~ ~V~
Engine erin g Gro~ h Connection

VENTURIMETER, ORIFICEMETER & ROTAMETER

TEST RIG

1. OBJECTIVE:

To demonstrate venturimeter, orificemeter and rotameter.

2. AIM:

2.1 To determine the co-efficient of discharge for venturimeter & orificemeter.

2.2 To calibrate the rotameter.

3. INTRODUCTION:

If a constriction is placed in a closed channel carrying a stream of fluid, there will be

increase in velocity, and hence increase in kinetic energy, at the constriction, from an
.
I

energy balance, as given by Bernoulli's .Theorem, there~~must be a corresponding

reduction in pressure. Rate of discharge .from the const@ion can be calculated by ~.: ·
knowing this pressure reduction, the area available for !"wat the constriction, the
"""'- .
density of fluid, and the co-efficient of discharge. The last -i fmed is defined as ratio of
;.
actual flow to the theoretical flow. .1 ..

~ ...
4. THEORY:

4.1 VENTURIMETER:

A Venturimeter consists of:

4.1.1 An inlet section followed by a convergent cone.
4.1.2 A cylindrical throat.
4.1.3 A gradually divergent cone.
The inlet section of venturimeter is of the same diameter as that of the pipe,
which is followed by a convergent cone. The convergent cone is a short pipe,
which tapers from the original size of the pipe to that of the throat of the
venturimeter. The Throat of the venturimeter is a short parallel side tube having
its cross-sectional area smaller than that of the pipe. The divergent cone of the
venturimeter is gradually diverging pipe with its cross-sectional area in~reasing

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 .s /..£."P
Eng lfl(JOnng Growt~ Connection

from that of the Th t t th . . .

roa a e anginal size of the pipe. At inlet section & throat of
the venturimeter, pressure taps are provided.

4.2 ORIFICEMETER:

An orifice meter consists of a flat circular plate with a circular hole called Orifice,
which is concentric with the pipe axis.
.,
I

4.2 ROTAMETER:
j
1

The rotameter is a variable - area meter that consists of an enlarging transparent

tube and a metering "float" (actually heavier than the liquid) that is displaced
upward by the upward flow fluid through the tube. The tube is graduated to read
the flow directly, Notches in the float cause it to rotate and thus maintain a central
position in the tube.

I 5. DESCRIPTION:
J

I The apparatus consists of a venturi meter, orifice meter and Rota meter, fitted in
I _ ....:...-

separate pipe. All pipes consist of separate flow control valves and common inlet and
f
dr~;~ fded for wat~~irculation through
II outlet. Sump tank with centrifugal pump is
....
. -
~"::::'
pipes.
The pressure tapings are provided at inlet antJ throat of ventt.Ji [gleter and inlet and outlet ~ .
conne~ted to a differeffj!~ 1 manometer. Discharge . .
r
J of orifice meter. Pressure tapings are
i . ~;,

is measured with the help of measuring tank .& stop watch. ~

i l. ~
6. UTILITIES REQUIRED:
,i .1
~ -.
l -:?

6.1 Electricity Supply: Single Phase, 220 V 'AC, 50 Hz, 5-1~~mp, combined socket
with earth connection.

6.2 Water Supply (Initial Fill).

6.3 Floor Drain Required. '

6.4 Floor Area Required: 1.5 m x 0.75 m.

7. EXPERIMENTAL PROCEDURE:

7.1 STARTING PROCEDURE:

FOR VENTURIMETER & ORIFICEMETER

7.1.1 Close all the drain valves.

K. C Engineers P vt. Limited, Ambal8

VENTURIMETER, ORIFICEMETER & ROTAMETER TEST RIG
Page No. 2 0'8 (Rev. 1)

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 ~~
~11.t-
Engineering Gro~tD Connection

7.1.2 Fill sump tank:X 'th I

4 WI C ean water and ensure that no foreign particles are
there .

7.1 .3 Open by-pass valve V1.

7.1.4 Ensure that OnlOff switch given on the panel is at OFF position.

7.1.5 Switch ON the main power supply and then switch on the pump.

7.1.6 Open flow control valve of desired test section (V2 for venturi meter or V3
for orifice meter).

7.1 .7 Connect the PU pipe from manometer to test section (Venturimeterl

Orifice meter)

7.1 .8 Open the air release valve V7 provided on the manometer, slowly to
release the air from manometer.

7.1.9 When there is no air in the manometer, close the air release valves.

7.1.10 Adjust water flow rate in desired section with t~~ help of control valve V2 or ~~.
V3 and by pass valve V1• /: I.: ~ ~~
. 1':. .. :~ . .:=:.
:~. 7..', ~

7.1.11 Record the manometer reading : in case of pr! ssure above scale in any :.:
f - -=:!'" ~.

tube, apply air pressure by hand l pump to get r~dable reading . ~

~ - .
"»
-:.:.

I 1;,
7.1 .12 Measure the flow of water, disc~arged throug@ esired test section, using ~.
stop watch and measuring tan~. j : ;;. . .:
I.' ! ~ ' 4 '~ ~ - - _ -11
.iiI - -~
7.1.13 Repeat Experiment for different flow rates
; I
ciE-water, operating Control :":
: i!
Valve V2 or V3 and by-pass valve V 1.

7.1.14 When experiment is over for one desired test section, open the by-pass
valve V1 fully.

7.1 .15 Then close the flow control valve V2 or V3 of running test section and open
the control valve V3 or V2 of another test section. (Orificemeter I
Venturimeter)

7.1.16 Connect the PU pipe from manometer to another test section.

(Orificemeter/ Venturimeter)

7.'\. '17 Repeat the experiment for 5.;. ie(;t~c1 test section.

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 !J,
Cng1rr(Joring G r~~ !h Con neelio n

FOR ROTAMETER

7.1.1 Close all the drain valves.

7.1 .2 Fill sump tank ~ with clean water and ensure that no foreign particles are
there.

7.1.3 Open by-pass valve V1 ·

7.1.4 Ensure that On/Off switch given on the panel is at OFF position .

7 .1.5 Switch ON the main power supply and then switch on the pump.

7.1.6 Open flow control valve V4 .

7 .1.7 Adjust water flow rate with the help of control valve V4 and by pass valve

V 1•

7.1.8 Measure the flow of water, discharged through desired test section, using

and measuring tank & stop watch .

7.1.9 Record the rotameter reading. I

, I ~ ~
7.1.10 Repeat the experiment for diffe're~' t flow rates 'o~water, operating control ~
valve V4 and by-pass valve V 1 .1 T h
.r~

7.2 CLOSING PROCEDURE:

7.2.1 Switch off the pump. I ,~ .

j .
7.2.2 Switch off the power supply to 'panel. .. .,..
•:J.

7.2 .3 Drain the sump tank & measuring tank.

8. OBSERVATION & CALCULATIONS:

8.1 DATA:

Acceleration due to gravity g 9.81 m/sec 2 Area of measuring tank A = 0.077 rri2
Diameter at throat d2 0.014 m Diameter at inlet d1 = 0.028 m

K. C. Engineers Pvt. Limited, Ambala

VEN TURIME TER, ORIFICEMETER & ROTAMETER TEST RIG
. P"m' No 4 of R (R",v 11
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 II~
-~~t-
Engineering Growth Connection

8.2 OBSERVATION TABLE:

I ,
I :'
I
I '
I
Test Section: Venturimeter 1 .'
Test Section: Orificemeter I'
I '
Sr. h1 h2 I'
R1 R2 t h1 h2 R1 t
R2 II
No (cm) (em) (em) (cm) (sec) (cm) (cm) (em) (cm) (sec) I
I
1 i
2
3
4
5

Test Section: Rotameter

Sr. FL R1 R2 t ,
I .

'No. '(LPH) (cm) (cm) (sec) f ' l

1 ,
2 I

3 I
I
4
5

_~..3 CALCULATIONS:

FOR VENTURIMETER & ORIFICEMETER

H = hi - h2 (m)
100

R = R1 -R2 (m)
100

Q = A x R (m 3/sec)
a t
7r d2
8, =- 1 (m )
2
4

7r d 22 (m 2)
8 2 =-
4

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 - .---~ . i f

Ill,
~,~
Engin~9rlng C!~~ Connection
Q _ 8,8 2 J2iH
I - .[ci2
a, -8
"2 (m%ec)
2

Cd == Oa
- Ot .
FOR ROTAMETER

R=
R 1 -R2 (m)
100
AxR
{

.~
t X 3600 X 1000 (LPH)
}

Error = (Ot - Qa) (LPH)

j 9. NOMENCLATURE:
J
i Nom Type
I
}
1
A Area of measuring tank
Column Headings Units
m' Given
a1 Area at inlet of venturimeter and orifice meter --.- m' Calculated
, -.
t a2 Area at throat of venturimeter and area 'of orifice ~-m' Calculated
f{ Cd Co-efficient of discharge , "-"
-- Calculated
-
d, Dia at inlet of venturimeter & orifice meter _;; m Given
d2 Dia at throat of venturimeter & dia of orifice '::: m Given
f ._-
-I
H
g Acceleration due to gravity
Loss of head, m of water
II
.,
i:
m/secL
m.'o fwater
Given
Calculated
-
h1 ,h2 Manometer reading at both paints, cm . , ~ cm Measured
j Oa Actual discharge (for Venturi, Orifice)
,
m:J/sec Calculated
Oa Actual discharge (for Rota meter) LPH Calculated
I
~

i at Theoretical discharge for venturi, orifice m.l/sec Calculated

t
; at Theoretical discharge for rotameter LPH Calculated

I,
I
R Rise of water level in measuring tank m Calculated
Measured
R, Final level of water in measuring tank em
R2 Initial level of water in measuring tank cm Measured
t Time taken for rise of water level in measuring sec Measured
' \
\
tank

K.C. Engineers Pvt. Limited, Amba/a VENTURIMETER, ORIFICEMETER & ROTAMETER TEST RIG
Page No _ 6 of 8.(Rev. 1)

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 Vl
~1,t."JI
Engineering Growth Connection
10. PRECAUTION &M
AINTENANCE INSTRUCTIONS:
10.1 Never run th
e apparatus if power supply is less than 200 Volts and
230 Volts above

10.2 Never fully close th fI

e ow control valve and by pass valve simultaneously.

10.3 To prevent clogging of moving parts, run pump at least once in a fortnight.

10.4 Always keep apparatus free from dust.

11. TROUBLESHOOTING:

11.1 If pump gets jammed, open the back cover of pump and rotate the shaft
manually.

11.2 If pump gets heated up, switch off the main power for 30 minutes and avoid
closing flow control valve and by-pass valve at a time, during operation.
_ ' . i

12.. REFERENCES:
1
1 / '

12.1 Streeter, Victor L. Wylie, E. Benjamin (1983). Fluid Mechanics.

. I
1st Ed.
McGraw Hill. pp 347-349,351-353,356'. ' .
I
.' I ' _ . .~

12.2 Bansal, R.K. (2008). Fluid Mechanics la nd Hydraulic Machines. 9 th Ed. NO: Laxmi i£.
I ~
Publications (p) Ltd. pp 265-266, 276-f80. j:
I ~
:~:.-

I I

K.C. Engineers P vt. Limited, Ambala \I~"'T/ ~~ /flACTr::O r'\~r:: I""':: "' :- """""" : ~
.....
-
~ ..-- - . -
~--- - _.
- .. - - -
~--.

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 ,~ .---- - - . ..- . _. . . . .,loo•• __ ..'~'- . .~
- .- - - -- ............. ~"",.,..- .. , ......" .,_ .........._ _ ....._ • • ' .. < I ..... _ - ' - " ....... _ _ _ ~_~i..,--.-... . :. ......"'·--·. . ---~
'-
Q)
C
C
13. BLOCK DIAGRAM:
co
U
(f)
E
co
/ r _____________________
u
vr ...c
:!:::
~
"'0
Q)
C
PRESSURETAPANG --------------____~~_, C
~-------------------MANOMETER co
v~~~~ __________________~ u

"0
(f)

.~,w""~~" 8
QRIFlCE METER
TEST SECTKlN
I '0' s~¥
~ :::J .
E 11..1~ (
~
..:
: UJI
~
v.
~I ~ B~ Ili.~~
-++-h
CONlROLPANEl. ,(i
I[}J
iF =::=u ~
V
v.

FLOW DiVERTER
ROTAMETER II II I If MEASURiNG TANK
) c: I

Ii;:( LEV El iNOiCATOR

.' ' ~ ..i
MEASURING SCAlE

OftlERGENT CHANNEL

~~;J .~ J=L.~
PUMP II ;' ,.)

VALVES

FRONT VIEW BLOCK DIAGRAM

V3 • fLOW C;ONTROL VALVE FOR ORIFtCE METER
J.
4.
••
;,
V6 _ DRAIN VA~VE
V4 • FLOW CONTROL VALVE fOR ROTAMETER
FOR SUMP TANK
V7. AIR RELEASE VALVE O.MANOMETER
NAME -VENTURiMETER & ORIFICEMET
CODE -HD·l0a Ell. & ROTAMI!TER T EST R IG

VENTURIMETER. ORIFICEMETER & ROTAMETER TEST RIG

. Page NO. 8 of 8 (Rev. 1)
K.C. EngineJfS Pvt. Limited. Ambala ! ~J l l l \i't~. II,I.~~·J
I
.C~ti~'II:lJi~!tI~\;';I'lj.iI~tli
•
"
 PITOT TUBE APPARATUS

1 OBJECTIVE:

To measure the velocity of flow at different points along the crosS section in a pipe.

2 AIM:
2.1 To find the Point velocity at the Centre of a tube for different flow rates.

2.2 To find the co-efficient of Pi tot tube.

2.3 To plot velocity profile across section of pipe.

3 INTRODUCTION:

It is a device used for measuring the velocity of flow at any point in a pipe. It is based
OJ) the principle that if the velocity of flow at points becomes zero, there is increase in
pressure due to theConversion of the kinetic energy into pressure energy. The pitot tube
consist of a capillary hlbe, bend at right angle .The lower end is directed in the upstream
direction. The liquid rises up in the tube due to conversion of kinetic energy into
press ure energy. Th e velocity is determined by measuring the rise ofliquid in the tube.

4 THEORY:

When a pitot is used for measuring the velocity of flow in a pipe or other closed conduit
the Pilot tube may be inserted in the pipe. Since a Pitot tube measures the stagnation
pressure head (or the total head) at its dipped end. The pressure head may be determined
directly by connecting a differential manometer between the Pitot tube and Pressure
taping at the pipe surface . Consider two points I and 2 at the same level in such 'a way
that point I is at the inlet of the pitot tube and point 2 is at the outlet. At point 1 the________
pressure is Pland the velocity of the stream vl .However, at point 2 the fluid is brought to
rest and the energy has been converted to pressure energy. Therefore the pressure at 2 is
P2, the velocity V2 is zero and I & 2 are in the same horizontal plane,
So zl =z2Appl yingBemoulli ' s equation at point (1) and (2).

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 --------~~~~-.

5 Description:_

The apparatus consists f t nk . h .

. 0 a Wlt centnfugal pump. A pitot tube made of copper provided
m .the test section made of acrylic connected to pipe line with flow control valve. The
pomter gauge is provided to measure the verticle position of pitot tube in test section. A
manometer is provided to determine the pressure difference. Discharge is measured with the
help of measuring tank and stopwatch.

6 UTILITIES REQUIRED:-

6.1 Electricity Supply:Single Phase,220 V AC,50 Hz,5-15 Amp. Combined

socket with earth connection.

6.2 Water Supply (initial fill).

6.3 Floor Drain Required.

6.4 Floor Area Required: 1.5 m x .75 m.

7 EXPE~ENTALPROCEDURE

7.1 STARTING PROCEDURE:

7.1.1 Close all the drain valves.

7.1.2 Fill sump tank :Y4 with clean water and ensure that no foreign paricJesare There.

7.1.3 Open by pass valve V2·

7.1.4 Ensure that On/Off switch given on the panel is at OFF position.

7.1 .5 Switch ON the main power supply and then switch on the pump.

7.1.6 Open flow control valve V I and allow water to flow through test section by partially
closing valve V2.

7.1.7 Open the air release valve V5 provided on the manometer,slowly to release the air from
manometer.

7.1.8 When there is no air in the manometer,c\ose the air release valve.

7.1.9 set the position of pitot tube at the centreof the centre of the test section by adjusting the
pointer to zero by knob provided.

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 7.1.10 Adjust water flow rat . d . d . .
e In eSlre section \vlth the help of with help of control valve VI
and bypass valve V 2•

7.1.11 Record the manometer readillg,in case of pressure above scale in any tube, Apply air
pressure by hand pump to get readable reading.
7.1.12 Measure the flow ofwater,discharged,lIsing stop watch and measuring tank.
7.1.13 Repeat Experiment for different flow rates of water ,operating control valve VI and by
pass -valve V2.

7.1.14 Record the manometer reading for different position of pitot tube (change by knob) at
particular discharge for determination of velocity profile.

7.2 CLOSING PROCEDURE

7.2.1 Switch off the pump.

7.2.2 Switch off the power supply to panel.

7.2.3 Drain the apparatus completely by drain valve VF and V4·

8. OBSERVATION & CALCULATIONS:

8.1 Data:

Acceleration due to gravity g"" 9.81 m/see z Area of measuring tank A -

0.077 m 2
Diameter of pipe d = 0.028 mt.

8.2.1 Observation Table:

Sr.No hl(cm) h2 (cm) RI (cm) R2 (em) tl (sec)

-- --.--- --~-~ - --- --

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 ..-
8.2.2 Observaf
Ion Table:
I-
Sr.No bl(em)
h2 (em)
r- RI (em) R2 (cm) tl (sec)
l-

I--

l-

f-

8.3 Caleulation:_

For Co-efficien t of velocity

R_Rl-R z
100

A*R
Qa=-t-
a = rrr2
Q
Va =-
a
hI-liz
H =- - (mt)
100 .

V = J2gH (m/sec)

For Velocity ProfiJe-

R 1 -R 2
R = - - (mt)
100
A·R J
Qa = -t (m /sec)
H = hl-h2 (mt) V = Cv.j2gH (m/sec)
100
Position

8
4
0
-4
-8
Use average of co-efficient of velocity calculated as Cv for velocity calculation.

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 Plot Graph: P vs'y

9 Nomenclature.

Nom
Column Heading Unit Type
A
Area of measuring tank m" Given
A
Cross section area of pipe m" Calculated
Cv
Co-efficient of pitot tub Calculated
D
Diameter of pipe m Given
G
Acceleration due to gravity m/sec" Given
h),h 2 Manometer reading at both pipe cm Measured
H Loss of head m of water Calculated
p
Position of pitot tube mm Measured
Q Discharge mJ/sec Calculated
R Rise of water level in measuring tank m Calculated
RI Final level of water in measuring tank cm Measured
R2 Initial level of water in measuring tank cm Measured
T Time for rise in water level in measuring tank sec Measured
V Velocity at any point m/sec Calculated
Va Actual velocity offluid m/sec Calculated
Vlh Theoretical velocity of fluid m/sec Calculated

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 1
i
10-Precaution and .
maIntenance Instruction'_
10.1 Never ru th .
n e apparatus if ow .
p er supply IS less than 200 V and above 230 Volts.
10.2 Never fully close the contr I
o valve VI and by pass valve V2 simultaneously.
10.3 To prevent clo in .
gg g of movmg parts,run pump at least once in a fortnight
10.4 always keep apparatus free from dust.

11 Troubleshooting:_

11.1 if pump gets jam, open the back cover of pump and rotate the shaft manually.

11.2 If the pump gets heated up ,switch off the main power for 30 min and avoids closing
the flow control valve V 1 and by-pass valve V2 at a time, during operation.

12 References:-

12.1 Modi, P. N. Seth, P.N. (2005)." Hydraulics and Fluid Mechanics including Hydraulic
Machines "15 th Ed. NO Rajinder Kumar Jain pp 293-295

12.2 Streeter, Victor L. Wylie, E. Benjamin (2007) "Fluid Mechanics" 9th Ed. NY:
McGraw Hill pp 337-339.

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 - ~\Vl..

E"r~ lne?ri llg Growl.ll Conn EC"JIC'lf\

~3.
)'1 '( \ I'
r' .
' .,

B LOCK D IAGRAM;

- - --.-- ---------------~---.- - ----~ -- ---------- ------- ---- ~---------- --

:~~---------v,

___ _ _ _ .__ .____. - -- - M ...N<......METER

PRE5SURE T....P?INQ - - - -_ _ __ _ _ _---,--

TE~~T~C~~; - - -- - - -- -- - ,
~-\
CONTRCLPANEl ~---_
--7\:-+-JHffi-t - - -- - - - - - KNOB
/ '- ----

FLOW OIVE RT ER

----++----+1---- - - -- \ L EVEL INOIC ....T OR

FRONT VIEW
B LOCI< DIAGRAIVr
~ NAl\olE:-:P""jTOp· TUi3-ESETUP
CODE - HO ."T11

K C. Engineers Pvt. Limited. Ambala PITOT TUBE APPAFlA TUS

Page No. 7 of 7 {Rev. 1J

-=------

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..
REYNOLD'S APPARATUS
1. OBJECTIVE:

To study different types of flow.

2. AIM:

2.1 To determine the Reynold's Number & hence the type of flow.

2.2 To study transition zone.

3. INTRODUCTION:

From an engineering viewpoint, many variables that affect velocity profile cannot be
evaluated for all possible flow meters and for all pipe conditions. For this reason,
steady flow and a fully developed flow profile as defined by a Newtonian,
homogeneous fluid are initially assumed. Co-efficient variation can then be predicted
with the dimensionless Reynolds number. This number has been found to be an
acceptable correlating parameter that combines the effects of viscosity, density and
pipeline velocity.

4. THEORY:

In Reynolds experiments, the ratio of inertia to viscous forces was observed to be

dimensionless and related to viscosity, average pipeline velocity, and geometrically
similar boundary conditions. For a homogeneous Newtonian fluid, this dimensionless
ratio is Re, is expressed as

Where, v = ~p
Re =
i
Dv :::
d?Rj
A
ci!,J-
~
,J

Re=-
v V-
Where,

p = Density of fluid in Kg/m 3

v = Average velocity of fluid flow in m/sec
D = Diameter of glass tube in m
f1 = Viscosity of fluid in N-sec/m 2
v = Kinematic viscosity of fluid,m 2/sec
Re < 2100 for laminar flow
Re > 4000 for turbulent flow
Re = 2100-4000 in transition zone
 When the dye filament flows in the Reynolds experiment, it indicates critical state of
flow and the corresponding Reynolds number is called the critical Reynolds number
Re~ 2000, beyond which the flow is in transition state and then becomes turbulent.

Depending upon the relative magnitudes of viscous and inertial forces, flow can occur
in two different manners. Laminar flow is defined as a line, which lies in the direction
of flow at every point at a given instant. Transition flow is defined as a flow in which
the streamlines needs not be straight as the flow steady as long as this criterion is
fulfilled. Eddies generated in the initial zone of instability spread rapidly throughout
the fluid thereby producing a disruption of the entire flow pattern. The result is fluid
turbulence superimposed upon the primary motion of translation, producing what is
called turbulent flow.

5. DESCRIPTION:

The apparatus consists of sump tank with centrifugal pump, a glass tube with one end
having bell mouth entrance connected to a constant head tank. At the other end of the
glass tube a valve is provided to regulate flow. Flow rate of water can be measured
with the help of measuring cylinder and stop watch, supplied with the set-up. A needle
is introduced centrally in the bell mouth. Dye is fed to the needle from a small
container, placed at the top of constant head tank, through polythene tubing.

6. UTILITIES REQUIRED:

6.1 Electricity Supply: Single Phase 220 V AC, 50Hz, 5-15 Amp. Combined socket with
earth connection. Earth voltage should be less than 5 volts.

6.2 Water Supply: Initial Fill.

6.3 Floor Drained required.

6.4 Floor area required: l.5m X 0.75m.

6.5 Chemical required: Dye (KMn04) - 10 gm

=='

7. EXPERIMENTAL PROCEDURE:

7.1 STARTING PROCEDURE:

7.1.1 Close all the valve Vi to Vs.

7.1.2 Fill sump tank 3/4 with clean water and ensure that no foreign particles are
there.

7.1.3 Prepare dye solution (KMn04, in water) in a beaker. Put this solution in Dye
vessel after ensuring that there are no solid particles in solution.

7.1.4 Open by pass valve Vz.

 7.1.5 Ensure that On/Off switch given on the panel is at OFF position.

7.1.6 Switch ON the main power supply and then switch on the pump.

7.1.7 Open control valve Vl, for water supply to constant head tank, partially
close by pass valve Vz and wait till overflow occurs.

7.1.8 Regulate minimum flow of water through glass tube by partial opening of
control valve V3 provided at the end of tube.

7.1.9 Then adjust the flow of dye through needle by knob, so that a fine colour
thread is observed.

7.1.10 Note the flow pattern observed (laminar, transition or turbulent).

7.1.11 Measure flow Rate using measuring cylinder and stop watch.

7.1.12 Repeat the experiment for different flow rate.

7.2 CLOSING PROCEDURE:

7.2.1 Switch off the pump.

7.2.2 Switch off power supply to panel.

7.2.3 Drain the apparatus completely by drain valves V4& Vs.

8. OBSERVATIONS AND CALCULATIONS:

8.1 DATA:
Kinematic viscosity of water at ambient temp. v -1.01E-06 mZ/s
Diameter of glass tube - 0.014 m

8.2 OBSERVATION TABLE

S.NO Vo(ml) t(s) Observed Flow Type
(Laminar /Transition/Turbulent)
1.
2.
3.
4.
5.
 8.3 CALCULATIONS:

Re=-
tiJ
v

9. NOMENCLATURE:

Nom Column Headings Units Type

a Cross sectional area of glass tube m2 Calculated
d Diameter of glass tube m Given
Q Discharge m 3 js Calculated
Re Reynold's Number * Calculated
t Time taken for Vo s Measured
V Average velocity of fluid flow mjs Calculated
Vo Volume of water collected in ml Measured
measuring cylinder
v Kinematic viscosity of water m 2 js Given

* Symbol represent unit-less quantity

10.PRECAUTIONS AND MAINTENANCE INSTRUCTIONS:

10.1 Never run the apparatus ifpower supply is less than 200 Volts and above 230 V.
10.2 Conduct the experiment when water gets stable.
10.3 Always use clean water.
10.4 To prevent clogging of moving parts, run pump at least once in a fortnight.

11. TROUBLESHOOTING:

If dye blocks the needle, remove the needle by disconnecting it from constant head
tank and pass air at some pressure through it.

12. REFERENCES:

Streeter, Victor L. Wylie, E. Benjamin (1983) Fluid Mechanics 1 Ed. NY: McGraw
Hill pp 195-198.
Modi, P. N. Seth, P.N. (2005). Hydraulics and Fluid Mechanics including
Hydraulic Machines 15 Ed. ND Rajinder Kumar Jain pp 454-455.
 Experiment
Efflux Time for a Tank with Exit Pipe

Objective:
To show the dependence of the efflux time for a tank with exit pipe on pipe length and
diameter.

Equipment:
The equipment consists of cylindrical tank, in a vertical position, the bottom outlet
being designed to carry one of a number of pipes having a range of internal diameters
and lengths. The tank is fitted with a spherical plug valve and a constant level pointer.

Specification:

The dimension, (H), (the depth of liquid in the tank) refers to the height of liquid
above the bottom (inside) of the tank.

The dimension, (L), is the distance from the inside bottom of the tank to the lower
extremity of the pipe. The construction of equipment is such that the dimension, (L),
for a particular pipe is the length of that pipe.

Figure : Efflux apparatus .

Theory:
A cylindrical tank, in a vertical position is to be drained through a pipe which is
vertically attached to the bottom of the tank. Assuming a quasi steady state
momentum balance and ignoring the head loss due to the entrance and exit of the pipe,
the pressure drop through the pipe is: \
L p.13 2
t1P = 4f·
d ·-2- .. · .. · .. · (1 )
Where:

~P: Pressure drop (N .m· 2 ) .

 f: Fanning friction factor, djmensionless,
L: Pipe length, (m). d: Pipe diameter, (m). p:
Liquid density, (Kg.m,3).

Time-average velocity through the pipe, (m.s'I).

Since the pressure drop, (~P), equals (~h.p.g) , where (~h), is the total head on the
system (i.e. H+L, where (H) is the depth of liquid in the tank), then :
L p.v 2
(L + H).p.g = 4[. d '-2-

or
-2 _ (L + H)g.d
v - ......... (2)
2.[ . L

when laminar flow occurs in the pipe, (f= 16/Re) and equation (2) becomes:

or
(L + H)p . g. d 2
V = 32.j.l.L
... ...... (3)

when turbulent flow occurs in the pipe, the Blasius equation: (f = O.079Re-O•25) is
applicable and equation (2) becomes:

or
_ (L + H)4/7. p1/7. g4/7. d S/ 7
v= (0.079 x 2)4/7.j.l1/7.L4f7 ......... (4)

where (Il) is the fluid viscosity (N.s.m,2).

For an incompressible fluid, flowing under isothermal conditions through a pipe of

length (L), equation (4) may be written:
4
V = (L + H)7. C ......... (4a)
where
g. d S / 4p1/4
C = [(0.079 x 2). L. j.ll/4] 4/7 ......... (5)

when fluid flows through the pipe in the system under consideration the liquid level in
the tank decreases and a mass balance gives:
dH _ d 2 _
dj"--(D ) .v ......... (6)
r
where:

t: time (s).
DT : tank diameter (m).
Substitution of equation (3) or (4) into equation into equation (6) and subsequent
integration gives the efflux time, (tefl), for laminar flow:
32.!1- L. Dr z [L + Hi]
t eff = 4 . in ......... (7)
p.g.d L+Hz

where:

HI : initial depth of liquid in the tank (m).

Hz: final depth of liquid in the tank (m).

For turbulent flow through the pipe, the efflux time is given by substituting and
integration:

teff -
_ 7 D/ 1 [ (L + Hi) 3/7 -
3·-;tz·C· (L + Hz) 3/7] ......... (8 )

Procedure:
1. Note the room temperature at the beginning and end of the investigation.
2. A mixture of glycerol and water is to be used as the fluid.
3. Use of viscometer to measure the fluid viscosity, and use a 50ml density bottle
to determine the density of the fluid.
4. Calculate the drop in liquid level in the tank corresponding to the removal of I
liter from the tank and hence calculate, (Hz).
5. Connect pipe 1 to the tank base.
6. Insert the plug valve in the base of the tank and fill the tank to about lOmm
above the constant level pointer with the mixture.
7. Hold a 1 liter beaker under the end of the pipe, remove the plug valve from its
seat and allow the mixture to run into the beaker until the constant level
pointer is just uncovered, this establishes full bore pipe flow. Immediately and
simultaneously, start a stop watch. When the mixture reaches the 1 liter mark,
stop the watch and simultaneously insert the plug valve in its seat.
8. Read the stop watch and record the result.
9. When the mixture has stopped dripping from the pipe, pour the contents of the
1 liter beaker into the tank; check that the tank level is about 10mm above the
constant level pointer and if necessary top up with the mixture.
10. Repeat steps 7 to 9 until two results agree to within 1%.
11. Remove pipe 1 and replace with pipe 2.
12. Repeat steps 7 to 10.
-.-

]3 . Repeat steps 11 and 12 for the remaining five pipes.

14. Take ofrepresentative sample of the mixture and determine its viscosity.
15. Collect the mixture in the stock bottle.

Calculation:
Remember to show specimen calculations:

1. List; in tabular form the three actual times and their averaged for each pipe.
2. Calculate the time-averaged velocity and hence time-averaged pipe Reynolds
number for each combination of pipe and liquid-list in tabular form.
3. Calculate the theoretical efflux time for each combination-list in tabular form.
4. Plot the ratio of experimental efflux time to the calculated efflux time (tEl'tc)
against (L) (i.e. tube length) for constant pipe diameter.
5. Plot the ratio of experimental efflux time to the calculated efflux time (tEl'tc)
against the ratio of tank diameter to tube diameter (DT/d) for constant pipe
length.
6. Confirm the dimensionality of equations (7) and (8) .

Reference:
F. A. Holland. "Fluid Flow for Chemical Engineers". Published by Edward Arnold,
1980.

Efflux Time for a Tank with Exit Pipe Data Sheet

Pipe dimensions Time (s) Trial Time (s) Trial

number 1 number 2
D=
L=
....
.....OJ
Q) D=
E
C\:l
-0
Q)
L=
E
C\:l
r/J

D=
..s::
......
b!l
C
L=
~
Q)

E
C\:l
D=
r/J