Fluid

Laboratory
Report

Student Name: ‫فلوباتير سمير بدرى‬

Student Number: 278
Section number: 7
 A. Valves and Measuring devices
I. Valves

Introduction
A valve is a device or natural object that regulates, directs or controls the flow of a
fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially
obstructing various passageways. Valves are technically fittings, but are usually
discussed as a separate category. In an open valve, fluid flows in a direction from
higher pressure to lower pressure. The word is derived from the Latin valva, the
moving part of a door, in turn from volvere, to turn, roll.

Valves have many uses, including controlling water for irrigation, industrial uses for
controlling processes, residential uses such as on/off and pressure control to dish and
clothes washers and taps in the home. Even aerosols have a tiny valve built in. Valves
are also used in the military and transport sectors. In HVAC ductwork and other near-
atmospheric air flows, valves are instead called dampers. In compressed air systems,
however, valves are used with the most common type being ball valves.

Applications
Valves are found in virtually every industrial process, including water and sewage
processing, mining, power generation, processing of oil, gas and petroleum, food
manufacturing, chemical and plastic manufacturing and many other fields.
People in developed nations use valves in their daily lives, including plumbing valves,
such as taps for tap water, gas control valves on cookers, small valves fitted to
washing machines and dishwashers, safety devices fitted to hot water systems, and
poppet valves in car engines. In nature there are valves, for example one-way valves in
veins controlling the blood circulation, and heart valves controlling the flow of blood
in the chambers of the heart and maintaining the correct pumping action.

Valves may be operated manually, either by a handle, lever, pedal or wheel. Valves
may also be automatic, driven by changes in pressure, temperature, or flow. These
changes may act upon a diaphragm or a piston which in turn activates the valve,
examples of this type of valve found commonly are safety valves fitted to hot water
systems or boilers. More complex control systems using valves requiring automatic
control based on an external input (i.e., regulating flow through a pipe to a changing
set point) require an actuator. An actuator will stroke the valve depending on its input

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and set-up, allowing the valve to be positioned accurately, and allowing control over a
variety of requirements.

Types
1. Ball Valve
A ball valve is a form of quarter-turn valve which uses a hollow, perforated and
pivoting ball to control flow through it. It is open when the ball's hole is in line with
the flow and closed when it is pivoted 90-degrees by the valve handle. The handle lies
flat in alignment with the flow when open, and is perpendicular to it when closed,
making for easy visual confirmation of the valve's status.

Ball valves are durable, performing well after many cycles, and reliable, closing
securely even after long periods of disuse. These qualities make them an excellent
choice for shutoff and control applications, where they are often preferred to gates and
globe valves, but they lack their fine control in throttling applications.

2. Butterfly Valve
A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing
mechanism is a disk that rotates.

Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly
valves are generally favored because they cost less than other valve designs, and are
lighter weight so they need less support. The disc is positioned in the center of the
pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating
the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball

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valve, the disc is always present within the flow, so it induces a pressure drop, even
when open.

3. Diaphragm Valve
Diaphragm valves (or membrane valves) consists of a valve body with two or more
ports, an elastomeric diaphragm, and a "weir or saddle" or seat upon which the
diaphragm closes the valve. The valve body may be constructed from plastic, metal,
wood or other materials depending on the intended use.

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 4. Gate Valve
A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier
(gate) out of the path of the fluid. Gate valves require very little space along the pipe
axis and hardly restrict the flow of fluid when the gate is fully opened. The gate faces
can be parallel but are most commonly wedge-shaped (in order to be able to apply
pressure on the sealing surface).

5. Globe Valve
A globe valve, different from ball valve, is a type of valve used for regulating flow in
a pipeline, consisting of a movable plug or disc element and a stationary ring seat in a
generally spherical body.
Globe valves are named for their spherical body shape with the two halves of the body
being separated by an internal baffle. This has an opening that forms a seat onto which

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a movable plug can be screwed in to close (or shut) the valve. The plug is also called a
disc or disk. In globe valves, the plug is connected to a stem which is operated by
screw action using a hand-wheel in manual valves. Typically, automated globe valves
use smooth stems rather than threaded and are opened and closed by an actuator
assembly.

6. Needle Valve
A needle valve is a type of valve with a small port and a threaded, needle-shaped
plunger. It allows precise regulation of flow, although it is generally only capable of
relatively low flow rates.

An instrument needle valve uses a tapered pin to gradually open a space for fine
control of flow. The flow can be controlled and regulated with the use of a spindle. A
needle valve has a relatively small orifice with a long, tapered seat, and a needle-
shaped plunger on the end of a screw, which exactly fits the seat.

7. Check Valve
A check valve, clack valve, non-return valve, reflux valve, retention valve or one-way
valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one
direction.
Check valves are two-port valves, meaning they have two openings in the body, one
for fluid to enter and the other for fluid to leave. There are various types of check

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valves used in a wide variety of applications. Check valves are often part of common
household items. Although they are available in a wide range of sizes and costs, check
valves generally are very small, simple, or inexpensive. Check valves work
automatically and most are not controlled by a person or any external control;
accordingly, most do not have any valve handle or stem. The bodies (external shells)
of most check valves are made of plastic or metal.

8. Relief Valve
A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or
limit the pressure in a system; pressure might otherwise build up and create a process
disturbance, instrument or equipment failure, or fire.

The pressure is relieved by allowing the pressurized fluid to flow from an auxiliary
passage out of the system. The relief valve is designed or set to open at a
predetermined set pressure to protect pressure vessels and other equipment from being
subjected to pressures that exceed their design limits.

When the set pressure is exceeded, the relief valve becomes the "path of least
resistance" as the valve is forced open and a portion of the fluid is diverted through the
auxiliary route. The diverted fluid (liquid, gas or liquid–gas mixture) is usually routed
through a piping system known as a flare header or relief header to a central, elevated
gas flare where it is usually burned and the resulting combustion gases are released to
the atmosphere. As the fluid is diverted, the pressure inside the vessel will stop rising.
Once it reaches the valve's reseating pressure, the valve will close.

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 9. Directional Control Valve
Directional control valves (DCVs) are one of the most fundamental parts of hydraulic
and pneumatic systems. DCVs allow fluid flow (hydraulic oil, water or air) into
different paths from one or more sources. DCVs will usually consist of a spool inside
a cylinder which is mechanically or electrically actuated. The position of the spool
restricts or permits flow, thus it controls the fluid flow.

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 10. Solenoid Valve
A solenoid valve is an electromechanically operated valve. Solenoid valves differ in
the characteristics of the electric current they use, the strength of the magnetic field
they generate, the mechanism they use to regulate the fluid, and the type and
characteristics of fluid they control. The mechanism varies from linear action, plunger-
type actuators to pivoted-armature actuators and rocker actuators. The valve can use a
two-port design to regulate a flow or use a three or more port design to switch flows
between ports. Multiple solenoid valves can be placed together on a manifold.

Solenoid valves are the most frequently used control elements. Their tasks are to shut
off, release, dose, distribute or mix fluids. They are found in many application areas.
Solenoids offer fast and safe switching, high reliability, long service life, good
medium compatibility of the materials used, low control power and compact design.

II. Measuring Devices

1. Liquid Column (Manometer)

Liquid-column gauges consist of a column of liquid in a tube whose ends are exposed
to different pressures. The column will rise or fall until its weight (a force applied due
to gravity) is in equilibrium with the pressure differential between the two ends of the
tube (a force applied due to fluid pressure). A very simple version is a U-shaped tube
half-full of liquid, one side of which is connected to the region of interest while the
reference pressure (which might be the atmospheric pressure or a vacuum) is applied
to the other. The difference in liquid levels represents the applied pressure. The
pressure exerted by a column of fluid of height h and density ρ is given by the
hydrostatic pressure equation, P = hgρ. Therefore, the pressure difference between the
applied pressure Pa and the reference pressure P0 in a U-tube manometer can be found
by solving Pa − P0 = hgρ. In other words, the pressure on either end of the liquid must
be balanced (since the liquid is static), and so Pa = P0 + ρgh.

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In most liquid-column measurements, the result of the measurement is the height h,
expressed typically in mm, cm, or inches. The h is also known as the pressure head.
When expressed as a pressure head, pressure is specified in units of length and the
measurement fluid must be specified. When accuracy is critical, the temperature of the
measurement fluid must likewise be specified, because liquid density is a function of
temperature. So, for example, pressure head might be written "742.2 mmHg" or
"4.2 inH2O at 59 °F" for measurements taken with mercury or water as the manometric
fluid respectively. The word "gauge" or "vacuum" may be added to such a
measurement to distinguish between a pressure above or below the atmospheric
pressure. Both mm of mercury and inches of water are common pressure heads, which
can be converted to S.I. units of pressure using unit conversion and the above
formulas.

2. Bourdon Gauge
The Bourdon pressure gauge uses the principle that a flattened tube tends to straighten
or regain its circular form in cross-section when pressurized. This change in cross-
section may be hardly noticeable, involving moderate stresses within the elastic range
of easily workable materials. The strain of the material of the tube is magnified by
forming the tube into a C shape or even a helix, such that the entire tube tends to
straighten out or uncoil elastically as it is pressurized. Eugène Bourdon patented his
gauge in France in 1849, and it was widely adopted because of its superior sensitivity,
linearity, and accuracy; Edward Ashcroft purchased Bourdon's American patent rights
in 1852 and became a major manufacturer of gauges. Also in 1849, Bernard Schaeffer
in Magdeburg, Germany patented a successful diaphragm (see below) pressure gauge,
which, together with the Bourdon gauge, revolutionized pressure measurement in
industry. But in 1875 after Bourdon's patents expired, his company Schaeffer and
Budenberg also manufactured Bourdon tube gauges.

In practice, a flattened thin-wall, closed-end tube is connected at the hollow end to a

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fixed pipe containing the fluid pressure to be measured. As the pressure increases, the
closed end moves in an arc, and this motion is converted into the rotation of a
(segment of a) gear by a connecting link that is usually adjustable. A small-diameter
pinion gear is on the pointer shaft, so the motion is magnified further by the gear ratio.
The positioning of the indicator card behind the pointer, the initial pointer shaft
position, the linkage length and initial position all provide means to calibrate the
pointer to indicate the desired range of pressure for variations in the behavior of the
Bourdon tube itself. Differential pressure can be measured by gauges containing two
different Bourdon tubes, with connecting linkages.

3. Venturi-Meter
A Venturi meter is basically a type of flow meter with a specially designed tube, used
to measure the flow velocity of liquids especially highly viscous liquids. It is one of
the most accurate means of measuring the flow. Just like Electromagnetic Flow meter,
it has no pressure drop (head loss) hence is very useful in places where pressure drop
should be minimal and where a greater emphasis is laid on the highest accuracy
achievable.

When a fluid, whose flow rate is to be determined, is passed through a Venturi meter,
there is a drop in the pressure between the Inlet section and Cylindrical Throat of
Venturi meter. The drop in pressure can be measured using a differential pressure
measuring instrument. Since this differential pressure is in direct proportion to the
flow rate as per the Bernoulli's Equation hence the differential pressure instrument can
be configured to display flow rate instead of showing differential pressure.

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 4. Orifice Plate
An orifice plate is a device used for measuring flow rate, for reducing pressure or for
restricting flow (in the latter two cases it is often called a restriction plate).
An orifice plate is a thin plate with a hole in it, which is usually placed in a pipe.
When a fluid (whether liquid or gaseous) passes through the orifice, its pressure builds
up slightly upstream of the orifice but as the fluid is forced to converge to pass
through the hole, the velocity increases and the fluid pressure decreases. A little
downstream of the orifice the flow reaches its point of maximum convergence, the
vena contracta where the velocity reaches its maximum and the pressure reaches its
minimum. Beyond that, the flow expands, the velocity falls and the pressure increases.
By measuring the difference in fluid pressure across tappings upstream and
downstream of the plate, the flow rate can be obtained from Bernoulli's equation using
coefficients established from extensive research.

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 5. Weir
A weir or low head dam is a barrier across the width of a river that alters the flow
characteristics of water and usually results in a change in the height of the river level.
There are many designs of weir, but commonly water flows freely over the top of the
weir crest before cascading down to a lower level.

Weir allows hydrologists and engineers a simple method of measuring the volumetric
flow rate in small to medium-sized streams/rivers or in industrial discharge locations.
Since the geometry of the top of the weir is known and all water flows over the weir,
the depth of water behind the weir can be converted to a rate of flow. However, this
can only be achieved in locations where all water flows over the top of the weir crest
(as opposed to around the sides or through sluices) and at locations where the water
that flows over the crest is carried away from the structure. If these conditions are not
met, it can make flow measurement complicated, inaccurate or even impossible.

6. Rotameter
A rotameter is a device that measures the volumetric flow rate of fluid in a closed
tube. It belongs to a class of meters called variable area meters, which measure flow
rate by allowing the cross-sectional area the fluid travels through to vary, causing a
measurable effect.

A rotameter consists of a tapered tube, typically made of glass with a 'float' (a shaped
weight, made either of anodized aluminum or a ceramic), inside that is pushed up by
the drag force of the flow and pulled down by gravity. The drag force for a given fluid
and float cross section is a function of flow speed squared only, see drag equation.
A higher volumetric flow rate through a given area increases flow speed and drag
force, so the float will be pushed upwards. However, as the inside of the rotameter is
cone shaped (widens), the area around the float through which the medium flows
increases, the flow speed and drag force decrease until there is mechanical equilibrium
with the float's weight.

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 7. Ultrasonic flow meter
An ultrasonic flow meter is a type of flow meter that measures the velocity of a fluid
with ultrasound to calculate volume flow. Using ultrasonic transducers, the flow meter
can measure the average velocity along the path of an emitted beam of ultrasound, by
averaging the difference in measured transit time between the pulses of ultrasound
propagating into and against the direction of the flow or by measuring the frequency
shift from the Doppler Effect. Ultrasonic flow meters are affected by the acoustic
properties of the fluid and can be impacted by temperature, density, viscosity and
suspended particulates depending on the exact flow meter.

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 B. Experiments Report

I. Centrifugal Pumps (Series and parallel)

Introduction
There may be many reasons to use parallel or series pumps instead of a single, larger
pump. These may include:
 Lower initial cost
 Lower installation cost
 Increased redundancy
 Easier maintenance

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  Lower operating cost
 Significant energy savings
The designer must possess clear knowledge of system design fundamentals in order to
achieve these benefits.

1. Parallel Pumping
Pumps are described as operating in parallel when they receive liquid from the same
suction manifold, and discharge into a common discharge manifold.
When two or more pumps are arranged in parallel their resulting performance curve is
obtained by adding the pumps flow rates at the same head as indicated in the figure
below.

Centrifugal pumps in parallel are used to overcome larger volume flows than one
pump can handle alone.

2. Series Pumping
Centrifugal pumps are connected in series if the discharge of one pump is connected to
the suction side of a second pump. Two similar pumps, in series, operate in the same
manner as a two-stage centrifugal pump.
When two (or more) pumps are arranged in serial their resulting pump performance
curve is obtained by adding their heads at the same flow rate as indicated in the figure
below.

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Centrifugal pumps in series are used to overcome larger system head loss than one
pump can handle alone.

II. Submersible Pump

Definition
A submersible pump is a device which has a hermetically sealed motor close-coupled to the
pump body. The whole assembly is submerged in the fluid to be pumped. The main
advantage of this type of pump is that it prevents pump Cavitation, a problem associated
with a high elevation difference between pump and the fluid surface. Submersibles are
more efficient than jet pumps. Hydraulic submersible pumps (HSP's) use pressurized fluid
from the surface to drive a hydraulic motor down hole, rather than an electric motor, and

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are used in heavy oil applications with heated water as the motive fluid.

Applications
Submersible pumps are found in many applications. Single stage pumps are used for
drainage, sewage pumping, general industrial pumping and slurry pumping. They are also
popular with pond filters. Multiple stage submersible pumps are typically lowered down a
borehole and most typically used for residential, commercial, municipal and industrial
water extraction (abstraction), water wells and in oil wells.

Other uses for submersible pumps include sewage treatment plants, seawater handling, fire
fighting (since it is flame retardant cable), water well and deep well drilling, offshore
drilling rigs, artificial lifts, mine dewatering, and irrigation systems.

Pumps in electrical hazardous locations used for combustible liquids or for water that may
be contaminated with combustible liquids must be designed not to ignite the liquid or
vapors.

Submersible pumps are most often used in the home for pumping water out of a basement.
However, they are used for many applications in industry.
 Sewage pumping
 Industrial Pumping
 Oil Industry
 Deep Well Drilling / Borehole Pumps
 Irrigation systems

III. Water Turbines

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Introduction
A water turbine is a rotary machine that converts kinetic energy and potential energy
of water into mechanical work.
Water turbines were developed in the 19th century and were widely used for industrial
power prior to electrical grids. Now they are mostly used for electric power
generation. Water turbines are mostly found in dams to generate electric power from
water potential energy.

Water wheels have been used for hundreds of years for industrial power. Their main
shortcoming is size, which limits the flow rate and head that can be harnessed. The
migration from water wheels to modern turbines took about one hundred years.
Development occurred during the Industrial revolution, using scientific principles and
methods. They also made extensive use of new materials and manufacturing methods
developed at the time.

Flowing water is directed on to the blades of a turbine runner, creating a force on the
blades. Since the runner is spinning, the force acts through a distance (force acting
through a distance is the definition of work). In this way, energy is transferred from
the water flow to the turbine.
Water turbines are divided into two groups: reaction turbines and impulse turbines.
Types
1. Francis turbine
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The Francis turbine is a type of water turbine that was developed by James B. Francis
in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial
and axial flow concepts.

Francis turbines are the most common water turbine in use today. They operate in a
water head from 40 to 600 m (130 to 2,000 ft) and are used primarily for electrical
power production. The electric generators that most often use this type of turbine have
a power output that generally ranges from just a few kilowatts up to 800 MW, though
mini-hydro installations may be lower. Penstock (input pipes) diameters are between 3
and 33 ft (0.91 and 10 m). The speed range of the turbine is from 75 to 1000 rpm. A
wicket gate around the outside of the turbine's rotating runner controls the rate of
water flow through the turbine for different power production rates. Francis turbines
are almost always mounted with the shaft vertical so as to isolate water from the
generator. This also facilitates installation and maintenance.

Applications
Francis turbines may be designed for a wide range of heads and flows. This versatility,
along with their high efficiency, has made them the most widely used turbine in the

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world. Francis type units cover a head range from 40 to 600 m (130 to 2,000 ft), and
their connected generator output power varies from just a few kilowatts up to 800
MW. Large Francis turbines are individually designed for each site to operate with the
given water supply and water head at the highest possible efficiency, typically over
90%.

In contrast to the Pelton turbine, the Francis turbine operates at its best completely
filled with water at all times. The turbine and the outlet channel may be placed lower
than the lake or sea level outside, reducing the tendency for cavitation.

In addition to electrical production, they may also be used for pumped storage, where
a reservoir is filled by the turbine (acting as a pump) driven by the generator acting as
a large electrical motor during periods of low power demand, and then reversed and
used to generate power during peak demand. These pump storage reservoirs act as
large energy storage sources to store "excess" electrical energy in the form of water in
elevated reservoirs. This is one of a few methods that allow temporary excess
electrical capacity to be stored for later utilization.

2. Kaplan turbine

The Kaplan turbine is a propeller-type water turbine which has adjustable blades. It
was developed in 1913 by Austrian professor Viktor Kaplan, who combined
automatically adjusted propeller blades with automatically adjusted wicket gates to

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achieve efficiency over a wide range of flow and water level.
The Kaplan turbine was an evolution of the Francis turbine. Its invention allowed
efficient power production in low-head applications which was not possible with
Francis turbines. The head ranges from 10–70 meters and the output ranges from 5 to
200 MW. Runner diameters are between 2 and 11 meters. Turbines rotate at a constant
rate, which varies from facility to facility. That rate ranges from as low as 54.5 rpm
(Albeni Falls Dam) to 450 rpm.
Kaplan turbines are now widely used throughout the world in high-flow, low-head
power production.

Applications
Kaplan turbines are widely used throughout the world for electrical power production.
They cover the lowest head hydro sites and are especially suited for high flow
conditions.

Inexpensive micro turbines on the Kaplan turbine model are manufactured for
individual power production designed for 3 m of head which can work with as little as
0.3 m of head at a highly reduced performance provided sufficient water flow.

Large Kaplan turbines are individually designed for each site to operate at the highest
possible efficiency, typically over 90%. They are very expensive to design,
manufacture and install, but operate for decades.

3. Pelton wheel

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A Pelton wheel is an impulse-type water turbine invented by Lester Allan Pelton in the
1870s. The Pelton wheel extracts energy from the impulse of moving water, as
opposed to water's dead weight like the traditional overshot water wheel. Many earlier
variations of impulse turbines existed, but they were less efficient than Pelton's design.

Water leaving those wheels typically still had high speed, carrying away much of the
dynamic energy brought to the wheels. Pelton's paddle geometry was designed so that
when the rim ran at half the speed of the water jet, the water left the wheel with very
little speed; thus his design extracted almost all of the water's impulse energy—which
allowed for a very efficient turbine.

Applications
Pelton wheels are the preferred turbine for hydro-power where the available water
source has relatively high hydraulic head at low flow rates. Pelton wheels are made in
all sizes. There exist multi-ton Pelton wheels mounted on vertical oil pad bearings in
hydroelectric plants. The largest units – the Bieudron Hydroelectric Power Station at
the Grande Dixence Dam complex in Switzerland – are over 400 megawatts.

The smallest Pelton wheels are only a few inches across, and can be used to tap power
from mountain streams having flows of a few gallons per minute. Some of these
systems use household plumbing fixtures for water delivery. These small units are
recommended for use with 30 meters (100 ft) or more of head, in order to generate
significant power levels. Depending on water flow and design, Pelton wheels operate
best with heads from 15–1,800 meters (50–5,910 ft), although there is no theoretical
limit.
The High Dam

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IV. Positive Displacement Pumps
Positive displacement pump (PDP) is a type of pump in which a moving fluid is
captured in a cavity and then discharges that fixed amount of fluid. The displacement

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of fluid takes place by some parts like plunger, piston, diaphragm etc. some of these
pumps have expanding cavity at the suction side and a decreasing cavity at the
discharge side. The liquid is sucked at the inlet side when the cavity expands and
discharges it when the cavity decreases.

In order to understand it more clearly, let’s take a syringe which has a piston inside it.
When the piston is drawn outward the cavity starts expanding and water starts to enter
into the syringe cylinder. As the piston is pressed inward the cavity keeps on
decreasing and the liquid inside the syringe experiences a force that makes the water
to escape out of the syringe. So what is the conclusion of the illustration? We have
seen in that the water is displaced from the syringe during suction and discharge stroke
of the piston.

Types

1. Rotary-Type Positive Displacement Pump

In this pump the fluid is moved by the use of a rotary part. It is the rotation which

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displaces the fluid from reservoir to the discharge pipe. The common examples of
these types of pumps are: internal gear, screw pump, flexible vane or sliding vane,
flexible impeller, circumferential pump, helical twisted roots etc.

The rotary type positive displacement pumps can be classified again into three main
types
 Gear pumps
In this pump, the fluid is moved in between two rotating gears. The liquid is
pushed between these two gears as it rotates.
 Screw pumps
These pumps consist of two screw type rotor turning against each other. When the two
screws rotate it sucks the water from the inlet and pumps it to the outlet.
 Rotary vane pumps
It is similar to scroll compressors. It consist of cylindrical rotor having vanes on it
which is encased in a similar (i.e. cylindrical type) shaped housing. When it rotates the
vanes on the rotor traps the fluid in between the rotor and casing and discharges it
through outlet.

2. Reciprocating Types Positive Displacement Pump

In these pumps, there is a reciprocating part (which moves backward and forward) to
pump the fluid. The reciprocating parts may be of plunger, piston or diaphragm type.
It contains valves, inlet valves and outlet valves. The inlet valves open and outlet
valves remain closed during suction of liquid. And inlet valves remain closed and
outlet valves get open during discharge of the liquid.

As shown in the diagram above, as the piston moves to the right, the cavity expands
and the water is sucked into it. And when the plunger moves to the left, it pushes the
liquid which makes the discharge valve opens and water starts discharging through the

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cavity.

Typically reciprocating pumps can be classified as

 Plunger pumps
A plunger is used for pumping water.
 Piston pumps
It has piston for pumping fluid.
 Diaphragm pumps
It works same as plunger pump but it has diaphragm for suction and discharge of
liquid.

V. Wind tunnel
Wind tunnels are large tubes with air blowing through them. The tunnels are used to
replicate the actions of an object flying through the air or moving along the ground.
Researchers use wind tunnels to learn more about how an aircraft will fly. NASA uses
wind tunnels to test scale models of aircraft and spacecraft. Some wind tunnels are
large enough to contain full-size versions of vehicles. The wind tunnel moves air
around an object, making it seem as if the object is really flying.

Most of the time, large powerful fans blow air through the tube. The object being
tested is held securely inside the tunnel so that it remains stationary and does not
move. The object can be a small model of a vehicle, or it can be just any part of a
vehicle. It can be a full-size aircraft or spacecraft. It can even be a common object like
a tennis ball. The air moving around the stationary object shows what would happen if
the object was moving through the air. The motion of the air can be studied in
different ways; smoke or dye can be placed in the air and can be seen as it moves
around the object. Colored threads can also be attached to the object to show how the
air moves around it. Special instruments can often be used to measure the force of the
air exerted against the object.

The development of wind tunnels accompanied the development of the airplane. Large
wind tunnels were built during World War II. Wind tunnel testing was considered of
strategic importance during the Cold War development of supersonic aircraft and
missiles.

The advances in computational fluid dynamics (CFD) modeling on high-speed digital

computers has reduced the demand for wind tunnel testing. However, CFD results are
still not completely reliable and wind tunnels are used to verify CFD predictions.
Classification

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 Low-speed wind tunnel
 High-speed wind tunnel
 Subsonic and transonic wind tunnel
 Supersonic wind tunnel
 Hypersonic wind tunnel
 High-enthalpy wind tunnel

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