Fluid Dynamics Lab Manual

1

EXPERIMENT No.1

FLOW MEASUREMENT BY ORIFICEMETER

1.1 AIM: To determine the co-efficient of discharge of the orifice meter

1.2 APPARATUS REQUIRED: Orifice meter test rig, Stopwatch

1.3 PREPARATION

1.3.1 THEORY

An orifice plate is a device used for measuring the volumetric flow rate. It uses the

same principle as a Venturi nozzle, namely Bernoulli's principle which states that there is a

relationship between the pressure of the fluid and the velocity of the fluid. When the velocity

increases, the pressure decreases and vice versa. An orifice plate is a thin plate with a hole in

the middle. It is usually placed in a pipe in which fluid flows. When the fluid reaches the

orifice plate, with the hole in the middle, the fluid is forced to converge to go through the small

hole; the point of maximum convergence actually occurs shortly downstream of the physical

orifice, at the so-called vena contracta point. As it does so, the velocity and the pressure

changes. Beyond the vena contracta, the fluid expands and the velocity and pressure change

once again. By measuring the difference in fluid pressure between the normal pipe section and

at the vena contracta, the volumetric and mass flow rates can be obtained from Bernoulli's

equation. Orifice plates are most commonly used for continuous measurement of fluid flow in

pipes.

Fig.1. Orifice Plate

1.3.2 PRE-LAB QUESTIONS

1. Write continuity equation for incompressible flow?

Mass flow rate = Density x Flow Area x Velocity of flow ……… kg/s

2. What is meant by flow rate?

Volume flow rate, Q = A V …………. m3/s

3. What is the use of orifice meter?

http://en.wikipedia.org/wiki/Volumetric_flow_rate

http://en.wikipedia.org/wiki/Venturi_effect

http://en.wikipedia.org/wiki/Bernoulli%27s_principle

http://en.wikipedia.org/wiki/Vena_contracta

http://en.wikipedia.org/wiki/Velocity

http://en.wikipedia.org/wiki/Pressure

http://en.wikipedia.org/wiki/Bernoulli%27s_equation



2

To measure the co-efficient of discharge and flow rate

4. What is the energy equation used in orifice meter?

Bernoulli‘s equation. Z1 + P1/ g +V12/2g= Z2 + P2/ g +V2

2/2g (Or)

1.4 PROCEDURE

N.B.: Avoid complete closing of supply valve (nearer to pump) or delivery valve

(nearer to collecting tank)

1. Switch on the power supply to the pump

2. Adjust the delivery flow control valve and note down manometer heads (h1, h2) and

time taken for collecting 10 cm rise of water in collecting tank (t). (i.e. Initially the

delivery side flow control valve to be kept fully open and then gradually closing.)

3. Repeat it for different flow rates.

4. Switch off the pump after completely opening the delivery valve.

1.5 OBSERVATIONS

1.5.1 FORMULAE / CALCULATIONS

The actual rate of flow, Qa = A x h / t (m3/sec)

Where A = Area of the collecting tank = lengh x breadth (m2

)

h = Height of water(10 cm) in collecting tank ( m),

t = Time taken for 10 cm rise of water (sec)

Qa = 0.009 / t ………… after using l, b and h.

The Theoretical discharge through orifice meter,

Qt = (a1 a2 2g H ) / (a12 – a2

2 ) m

3/sec

Where, H = Differential head of manometer in m of water = 12.6 x hm x 10 -2

(m)

g = Acceleration due to gravity (9.81m/sec2)

Inlet Area of orifice meter in m2 , a1 = d1

2/ 4 ,

Area of the throat or orifice in m2

, a2 = d22/ 4

Qt = 14.85 x 10-4

H …….. after using a1, a2 and g values.

3

The co-efficient of discharge, Cd = Actual discharge / Theoretical discharge = Qa/Qt

1.5.2 TABULATION

Size of Orificemeter : Inlet Dia. d1 = 25 mm , Orifice dia d2 = 18.77 mm,

Measuring area in collecting tank A = 0.3 x 0.3 m2

Sl.

No.

Manometer Reading

(cm)

Manomet

er Head

H

Time for

10 cm rise

t

Actual

Discharge

Qa

Theoretical

Discharge

Qt

Co-eff. of

discharge

Cd

h1 h2 hm =

h1 - h2

m sec m3/sec m

3/sec

1. 23 17.5 5.5 0.693 7.6 0.0012 0.0013 0.92

2. 25 15.5 9.5 1.19 8.9 0.0013 0.0016 0.81

3. 26.5 14 12.5 1.5 9.0 0.0015 0.0018 0.83

4. 27.5 13 14.5 1.82 9.2 0.0016 0.0020 0.80

5.

Average Cd value 0.84

1.5.3 GRAPH:

Qa Vs Qt .

Find Cd value from the graph and compare it with calculated Cd

1.6 POST-LAB QUESTIONS

1. How do you find actual discharge?

By calculating the time taken for the volume of water coming to the collecting tank

with the help of formula, Qa = A x h / t

2. How do you find theoretical discharge?

Based on the pressure head difference and the area of pipe and orifice.

3. What do you meant by co-efficient of discharge?

It is the ratio of actual discharge to theoretical discharge.

1.7 INFERENCES

4

Fig. 1. Orifice meter (Qa Vs Qt)

1.8 RESULT

The co-efficient of discharge of orifice meter = 0.84….…. From Calculation

The co-efficient of discharge of orifice meter = 0.60……. From Graph

5

2. FLOW MEASUREMENT BY VENTURIMETER

1.1 AIM: To determine the co-efficient of discharge of the venturimeter

1.2 APPARATUS REQUIRED: Venturimeter test rig, Stopwatch

1.3 PREPARATION

1.3.1 THEORY

Fig.2. Venturimeter

In a Venturi meter there is first a converging section in which the cross sectional area

for flow is reduced. Then there is a short section at the reduced diameter, known as the throat

of the meter. Then there is a diverging section in which the cross sectional area for flow is

gradually increased to the original diameter. The velocity entering the converging section is

where the pressure is P1. In the converging section the velocity increases and the pressure

decreases. The maximum velocity is at the throat of the meter where the minimum pressure P2

is reached. The velocity decreases and the pressure increases in the diverging section. There is

a considerable recovery of pressure in the diverging section. However, because of frictional

effects in the fluid, the pressure leaving the diverging section is always less than P1, the

pressure entering the meter.


1. Differentiate mass and volume flow rate?

Mass flow rate is involving density and volume flow rate is applicable for

incompressible flow.

2. Which property is remains same in the incompressible flow?

Density of the fluid

3. What is meant by discharge?

It is the flow rate. Litres per minute (lpm) or m3/s

4. What is the use of venturimeter?

To measure the flow rate through the pipes.

6

1.4 PROCEDURE:

N.B.: Avoid complete closing of supply valve (nearer to pump) or delivery valve

(nearer to collecting tank).

1. Switch on the power supply to the pump

2. Check any air bubbles inside the manometer tubes connected to the venturimeter.

(If air bubbles present means, open the top levers (cocks) of the manometer

Simultaneously and adjust the delivery valve in order to release the air. After the air

released, close the top levers simultaneously)

3. Adjust the delivery flow control valve and note down manometer heads (h1, h2) and

time taken for collecting 10 cm rise of water in collecting tank (t). (i.e. Initially the

delivery side flow control valve to be kept fully open and then gradually closing.)

4. Repeat it for different flow rates.

5. Switch off the pump after completely opening the delivery valve.

1.5 OBSERVATIONS


The actual rate of flow rate Qa = A x h (m3/sec)

t


)



Qa = 0.009 / t ………… after using l, b and h.

The Theoretical flow rate or discharge through a venturimeter,

Qt = (a1 a2 2g H ) / (a12 – a2

2 ) m

3/sec

Where, H = Differential head of manometer in m of water = 12.6 x hm x 10 -2

(m)

g = Acceleration due to gravity (9.81m/sec2)

Inlet Area of Venture meter in m2 , a1 = d1

2/ 4 ,

Area of the throat in m2

, a2 = d22/ 4

Qt = 14.88 x 10-4

H …….. after using a1, a2 and g values.

The co-efficient of discharge, Cd = Actual discharge / Theoretical discharge = Qa/Qt

7

1.5.2 TABULATION:

Inlet Dia. Of Venturimeter OR Dia of Pipe d1 = 25 mm

Throat diameter of Venturimeter d2 = 18.77 mm

Area of collecting tank , A = Length x Breadth = 0.3 x 0.3m2

Sl.

No.

Manometer Reading

(cm)

Manomet

er Head

H

Time for

10 cm rise

t

Actual

Discharge

Qa

Theoretical

Discharge

Qt

Co-eff.

Of

discharge

Cd h1 h2 hm =

h1 - h2

m sec m3/sec m

3/sec

1. 32.4 26.4 6.0 0.76 7.4 0.00122 0.00130 0.94

2. 32 26.7 5.3 0.67 7.6 0.00118 0.00122 0.96

3. 30 25 5.0 0.63 7.9 0.00114 0.00118 0.96

4. 19 23.8 4.8 0.60 8.2 0.00110 0.00115 0.95

5.

Average Cd value 0.95

1.5.3 GRAPH:

Qa Vs Qt .

Find Cd value from the graph and compare it with calculated Cd


1. How do you find actual and theoretical discharge?

We will find the Actual discharge by volume of tank and time taken and theoretical

flow rate will be by using the pipe diameter,throat diameter and pressure head(

manometer heads).

2. What do you meant by throat of the venturimeter?

It is the minimum cross-section of the meter.

3. List out the practical applications of Bernoulli‘s equation?

Flow measurement in open and closed channels e.g. pipes, tanks, rivers, weirs etc.

4. What is the use of U-tube manometer?

To find the pressure difference between the two sections of same pipe.

8

Fig.2. Venturimeter (Qa Vs Qt)

1.7 INFERENCES

1.8 RESULT

The co-efficient of discharge of Venturi meter = 0.95 From Calculation

The co-efficient of discharge of Venturi meter = 0.75 From Graph

9

3.VERIFICATION OF BERNOULLIS THEOREM

1.1 AIM: To verify the Bernoulli‘s theorem

1.2 APPARATUS REQUIRED: Bernoulli‘s Theorem test set-up, Stopwatch

1.3 PREPARATION

1.3.1 THEORY

Bernoulli’s Theorem

According to Bernoulli‘s Theorem, in a continuous fluid flow, the total head at any

point along the flow is the same. Z1 + P1/ g +V12/2g= Z2 + P2/ g +V2

2/2g , Since Z1 –Z2 = 0

for Horizontal flow, h1 +V12/2g= h2 +V2

2/2g ( Pr. Head, h = P1/ g ). Z is ignored for adding

in both sides of the equations due to same datum for all the positions. Bernoulli‘s equation is

based on Euler‘s equation of motion. It is applicable to flow of fluid through pipe and channel.

In Euler‘s equation the force of viscosity is neglected. Bernoulli‘s equation is required to be

modified if the flow is compressible and unsteady.

Apparatus

The apparatus is fitted with piezometer tubes and scales at 8 cross sectional points,

along the experimental duct at suitable intervals for measurement of pressure head. The area of

flow section (a) is written on each one of these 8 sections. The velocity of flow (V) can be

calculated at each of these sections from the flow rate(Q) obtained from the measuring tank

that is V = Q/a from this velocity head V2/2g can be calculated for each section.

For the verification of Bernoulli‘s theorem, the velocity head when superposed over the

hydraulic gradient gives the energy gradient must be a level line. However, in the flow of need

fluid, contain losses of energy is inevitable and this can be readily seen by plating energy

gradient.


1. State Bernoulli‘s theorem?

Z1 + P1/ g +V12/2g= Z2 + P2/ g +V2

2/2g

2. What is continuity equation?

It is mass balance equation. M = ρ A V = ρ Q

3. What do you meant by potential head?

The head of energy due to position (height) from a reference level

1.4 PROCEDURE

1. Switch on the pump

2. Fix a steady flow rate by operating the appropriate supply and drain valves.

3. Note down the pressure heads (h1 – h8)

4. Note down the time taken for 10 cm rise of water in measuring (collecting) tank.

5. Switch off the power supply.

10

1.5 OBSERVATIONS


Rate of flow Q = Ah /t.

Where A: Area of measuring tank = Length x Breadth (m2)

h: Rise of water in collecting tank (m) .. (i.e. h = 10 cm )

t: Time taken for 10 cm rise of water in collecting tank (sec)

Velocity of flow, V = Q/a ,

Where a – Cross section area of the duct at respective peizometer positions (a1 – a8)

Hydraulic Gradient Line (HGL) : It is the sum of datum and pressure at any point

Total Energy Line (TEL): It is the sum of Pressure head and velocity head

Total Head = Datum + TEL

1.5.2 TABULATIONS

Area of measuring tank = 0.3 x 0.3 m2 ,

Datum head Z = 0

Diameter at the

sections of the

channel

d

Cross –

Section

Area

a = d2/ 4

Time

for 10

cm rise

t

Dischar

ge

Q=Ah/t

x 10-3

Velocity

V=Q/a Velocity

Head

V2/2g

x 10-3

Piezometer

Reading i.e.

Pr. Head

(h=P/g )

Total Head

Z +h+

V2/2g

m x10-3

m2 sec m

3/sec m/sec m m m

d1 = 0.04295

1.448

36.8

0.2445

0.168 1.44 0.296 0.297

d2 = 0.03925

1.209 0.202 2.08 0.294 0.296

d3= 0.03555

0.992 0.246 0.08 0.286 0.289

d4= 0.03185

0.796 0.307 4.8 0.284 0.288

d5 = 0.02815

0.622 0.393 7.9 0.280 0.287

d6= 0.02445

0.469 0.521 13.8 0.272 0.286

d7= 0.02075

0.338 0.724 26.68 0.248 0.275

d8= 0.01705

0.228 1.071 58.46 0.206 0.256

1.5.3 GRAPH

Draw the graph : Distance (x1- x8) Vs Piezometric head (HGL), Kinetic Head (TEL)

11

Fig.3. Bernoulli’s Theorem (Distance Vs TEL, HGL)

12


1. What do you meant by velocity head?

The head of energy due to pressure of the fluid in m

2. What do you meant by pressure head?

The head of energy due to K.E. (velocity) of the fluid in m

3. What do you meant by datum head?

The head of energy due to position (height) from a reference level

4. What is the use of piezometer? The tube used to show the pressure head in m. Its one

end is connected to the point where the pressure is to be measured and other end is

open to atmosphere.

5. Practically the total head of liquid at a point does not remain constant during the flow,

why? The total energy remains constant due to Bernoulli‘s theorem.

6. The liquid level in the piezometric tube connected to minimum c/s area is lowest,

Why? The pressure head is converted into kinetic or velocity head.

7. Why the water levels in the various piezometric tubes are different?

The pressure is decreasing due to the reduction in the cross section and the pressure

head is converted into KE (i.e. the velocity is increasing)

8. What do you mean by piezometric head?

It is the sum of the pressure head and datum head of the flow. (h+Z)

1.7 INFERENCES

The differences in the total head values are due to the loss of head due to friction,

fittings etc.

1.7 RESULT

The Bernoulli‘s theorem is verified.

13

4.DETERMINATION OF PIPE FRICTION FACTOR

1.1 AIM: To determine the friction factor for the given pipe

1.2 APPARATUS REQUIRED: Pipe friction apparatus, Stop watch

1.3 PREPARATION

1.3.1 THEORY

The major loss in the pipe is due to the inner surface roughness of the pipe. There

are three pipes (diameter 25 mm, 20 mm and 15 mm ) available in the experimental set up. The

loss of pressure head is calculated by using the manometer. The apparatus is primarily designed

for conducting experiments on the frictional losses in pipes of different sizes. Three different

sizes of pipes are provided for a wide range of experiments. Each individual pipe can be

connected to the manometer through the pressure feed pipes opening the corresponding cocks.

While taking reading close all the valves in the pressure feed pipe except the two (upstream and

downstream) valves cocks which directly connects the manometer to the required pipe, for which

the loss in head has to be determined. (Make sure while taking readings that the manometer is

properly primed. Priming is the operation of filling the manometer upper parts and the

connecting pipes with water and venting the air from the pipes).


1. What do you meant by friction and list out its effects?

The friction is the wall shear force acting on the fluid by the metal surface.

Effects of friction are energy loss, pressure drop in the fluid.

2. What do you meant by major loss in pipe?

The major energy loss in the pipe is due to friction only.

3. Write down the Darcy-Weisbach equation?

The frictional loss of head in pipes is given by the Darcy-Weisbach formula.

hf = f L V2 / (2 g d )

4. What are the types of losses in pipe flow?

Major loss and Minor losses due to pipe fittings like bend, joints etc.

14

1.4 PROCEDURE

1. Switch on the pump and choose any one of the pipe and open its corresponding

valves to the manometer.

2. Adjust the delivery control valve to a desired flow rate. (i.e. fully opened

Delivery valve position initially)

2. Take manometer readings and time taken for 10 cm rise of water in collecting

tank

3. Repeat the readings for various flow rates by adjusting the delivery valve. (i.e.

Gradually closing the delivery valve from complete opening)

4. Switch of the power supply after opening the valve completely at the end.

1.5 OBSERVATIONS


The actual rate of flow Q = A x h (m3/sec)

t


)



The frictional loss of head in pipes is given by the formula.

hf = 4 f L V2

2 g d

Where f = Co-efficient of friction for the pipe (to be found)

L = Distance between two sections for which loss of head is measured = 3 m

V = Av. Velocity of flow = Q/a (m/s),

Area of pipe a= d2/ 4 (m

2),

d = Pipe dia = 0.015 m

g = Acceleration due to gravity = 9.81 m/sec2

hf = Loss of head in metres

= hm ( Sm – Sf)/ (Sf x 100) in m

= hm (13.6 – 1 ) x 10 -2

(m)

Where Sm = Sp. Gr. of manometric liquid , Hg =13.6 ,

Sf = Sp. Gr. of flowing liquid, H2O = 1

hm = Difference in manometric reading = (h1-h2) in cm

hf can be found by the above formula (data from the manometer). The rest of the factors except

‗hf‘ being known, the valve of ‗f‘ can be determined.

15

1.5.2 TABULATION

Length between Pressure tapping, L = 3 m

Pipe Diameter, d = 0.015 m,

Height of water rise in the collecting tank, h = 0.10 m

Measuring tank area, A= 0.6 x 0.3 m2 ,

Sl.No. Pipe

Dia

Manometer Reading Head

loss

Time for

10 cm

rise

Discharge Velocity Frictional

factor

f d h1 h2 hm =

(h1-h2)

hf t Q V=Q/a

m cm m sec m3/s m/s

1

0.015

11 20.0 9 1.13 21.7 0.00083 4.7 0.0050

2 11.5 19.5 8 1.01 23.3 0.00077 4.35 0.0052

3 12.5 18.5 6 0.76 26 0.00069 3.92 0.0048

4 14.5 16.5 2 0.25 59 0.00031 1.73 0.0083

5

Average friction factor, f 0.0058

1.5.3 GRAPH

Draw the graph: Q Vs hf


2. What is the relationship between friction head loss and pipe diameter?

The friction head loss is inversely proportional to the pipe diameter.

3. What is the relationship between friction head loss and flow velocity?

The friction head loss is square of the flow velocity. hf V2

4. What is the relationship between friction head loss and pipe length?

The friction head loss is directly proportional to the pipe length.

16

Fig.4. Major loss in pipes (Friction loss) (Q Vs hf)

1.7 INFERENCES

1.8 RESULT

The friction factor for the given pipe diameter of 0.015 m is = 0.0058

17

5. PERFORMANCE TEST ON GEAR PUMP

1.1 AIM: To study the performance of gear oil pump.

1.2 APPARATUS REQUIRED: Gear pump test rig, Stopwatch

1.3 PREPARATION

1.3.1 THEORY

A gear pump uses the meshing of gears to pump fluid by displacement. They are

one of the most common types of pumps for hydraulic fluid power applications. Gear

pumps are also widely used in chemical installations to pump fluid with a certain

viscosity. There are two main variations; external gear pumps which use two external

spur gears, and internal gear pumps which use an external and an internal spur gear. Gear

pumps are positive displacement (or fixed displacement), meaning they pump a constant

amount of fluid for each revolution. Some gear pumps are designed to function as either a

motor or a pump. The gear oil pump is works based on the squeezing action of the two

meshing gears (internal or external gears). The gear pump is one of the positive

displacement pump and the reduction in volume inside the pump results in increase in

pressure of fluid.

As the gears rotate they separate on the intake side of the

pump, creating a void and suction which is filled by fluid. The

fluid is carried by the gears to the discharge side of the pump,

where the meshing of the gears displaces the fluid. The

mechanical clearances are small— in the order of 10 μm. The

tight clearances, along with the speed of rotation, effectively

prevent the fluid from leaking backwards. The rigid design of

the gears and houses allow for very high pressures and the

ability to pump highly viscous fluids.

Fig.3. External Gear pump


1. What is the purpose of gear pump?

Gear pump is a positive displacement pump and it is used to increase the pressure of high

viscous liquids.

2. What do you meant by internal and external gears?

The external gears the meshing teeth are only outer side of the driver and follower

whereas in the internal gears, one gear is having external teeth and other one is having

external teeth.

3. What are the applications of gear pump?

To pump the lubricating oil to a higher head ( to increase the pressure of oil)

http://en.wikipedia.org/wiki/Pump

http://en.wikipedia.org/wiki/Hydraulic_machinery

http://en.wikipedia.org/wiki/Gear

http://en.wikipedia.org/wiki/Positive_displacement_pump

http://en.wikipedia.org/wiki/Hydraulic_motor

http://en.wikipedia.org/wiki/Fluid

http://en.wikipedia.org/wiki/Viscosity

18

4. What is known as viscosity?

The property of a fluid whidh offers resistance to the movement of one

layer of fluid over adjacent layers of fluids is called viscosity.

1.4 PROCEDURE

N.B. : NEVER operate the pump with closed delivery valve. The pumping action is

continuous in this positive displacement pump. Gear Pump works (pumps) irrespective of the

output or delivery. The violation leads to damage of the pipe line and the pump.

1. Ensure the complete opened position of delivery valve.

2. Measure height of the pressure gauge above the vacuum gauge.

3. Switch on the pump.

4. Vary the flow rate (discharge) by closing the delivery valve.

5. Adjust the delivery valve accordingly the pressure gauge reading of 0.5 kg/cm2.

6. Note down vacuum gauges reading.

7. Note down time taken for ‗h‘ cm rise of oil (10 cm) in collecting tank.

8. Note down the time taken for ‗n‘ revolutions for energy meter disc (3 rev).

9. Repeat the procedure for 0.5 kg/cm2 incremental by closing the delivery valve gradually,

(i.e. 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg/cm2 ).

10. Switch off the power supply after opening the delivery valve completely.

1.5 OBSERVATIONS


Total head H = P x 105/ ( g) + (V x 10

5/(760 g) ) +Z (m)

Where P - kg/cm2, V- mm Hg,

N.B.: For V, 1 mm Hg/ 760 = 1 bar & for P, 1 bar = 1 kg/ cm2

.

Density of oil , = 860 kg/m3

Discharge, Q = (A x h ) / t (m3/s) ,

Where A = Area of tank in m2

,

h = Rise oil level in collecting tank (m),

t = Time taken for the rise of oil 10 cm in collecting tank (sec)

Output in Watts, OP = g Q H / 1000 (kW)

Input in Watts , IP = (n x 3600 x m ) / (Ec x T) (kW)

Where Ec = Energy meter constant in Rev /kWh = 1200 Rev / kWh

n = Number of revolution taken in energy meter = 3

T = Time required to complete ‗n‘ revolution in sec

m = Efficiency of motor = 0.80

Efficiency, = Output / Input x 100%

19

1.5.2 TABULATION

Measuring Area in collecting tank = 0.3x0.3m2

Datum head Z = 0.3 m

Sl.

No.

P

V

Z

H

Time

for

10cm

rise

(t)

Flow

rate

Q

Time for

3 rev of

Energy

meter

(T)

Input

IP

Output

OP

Effici

- ency

kg/cm2 mm

Hg

m m Sec m3/sec sec kW kW %

1 1.0 140

0.3

14.33 16.71 0.00054 32 0.23 0.065 28.31

2 1.5 140 20.26 17.13 0.00053 26 0.28 0.091 32.50

3 2.0 130 26.03 18.81 0.00048 22 0.33 0.105 31.82

4 2.5 110 31.64 19.13 0.00047 19 0.38 0.126 33.16

5 3.0 110 37.57 19.78 0.00046 17 0.42 0.146 34.76

6

1.5.3 GRAPH

Draw the graph: Discharge Vs Head, Output and Efficiency.


1. What is the squeezing in gear pumps?

The pressuring of fluid by passing through the reduced flow area and the

volume is reduced due to meshing of the gears.

2. What is the type of gears used in gear pumps? Spur gears

3. List out the different pressure heads used in gear pump?

Static head, Pressure and vacuum heads

4. What is mechanical efficiency of pump?

It is the ratio of hydraulic output power to motor shaft input power.

20

Fig.5. Performance of Gear oil pump ( Q vs H, OP, Efficiency)

1.7 INFERENCES

1.8 RESULT

The performance characteristics of the given gear oil pump are studied.

21

6. PERFORMANCE TEST ON SUBMERSIBLE PUMP

1.1 AIM: To study the performance of submersible pump at constant speed.

1.2 APPARATUS REQUIRED: Submersible pump test rig, Stop watch

1.3 PREPARATION

1.3.1 THEORY

A submersible pump (or electric submersible pump (ESP)) 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. Submersible pumps push fluid to the surface as opposed to jet pumps having to pull

fluids. Submersibles are more efficient than jet pumps


1. What is the submersible pump?

2. What is the working principle of submersible pump?

3. What are applications of submersible pump?

1.4 PROCEDURE

1. Start the pump and run it at particular head on it.

2. Ensure the complete opening of the delivery valve provided.

3. The pressure gauge reading to be noted for the pressure of 0.5 kg/cm2.

4. The time is to be noted for collecting 10 cm rise of water in the collecting tank.

5. The time is to be noted for 3 revolution of Energy meter disc.

6. Repeat the procedure for 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 kg/cm2 delivery pressures.

by closing the delivery valve.

7. Open the delivery valve completely and then Switch off the power supply.

1.5 OBSERVATIONS


Total Head, H = P x 105/ ( g) …… in m

Where P – Pressure gauge reading in kg/cm2,

g = Gravitational acceleration = 9.81 m2/s

= Density of fluid (water) = 1000 kg/m3

Discharge, Q = (A x h ) / t (m3/sec)

Where A = Area of tank in m2 A = l x b

h = Rise of water level in collecting tank = 0.10 m

t = Time taken for 10 cm rise of water in the collecting tank

http://en.wikipedia.org/wiki/Hermetic_seal

http://en.wikipedia.org/wiki/Electric_motor

http://en.wikipedia.org/wiki/Cavitation



http://en.wikipedia.org/wiki/Eductor-jet_pump

22

Output in kW, OP = g QH / 1000

Input in kW, IP = (n x 3600 m ) / (N x T)

Where N = Energy meter constant in Rev /kWh = 1200 rev / kWh

n = Number of revolution taken in energy meter



Efficiency, = Output / Input x 100%

1.5.2 TABULATION

Measuring tank of size = 0.5 x 0.5 m2

1.5.3 GRAPH: Draw the graph Q Vs H, OP and


1. How do you measure actual flow rate?

2. What is the output power of the pump?

3. List out the different heads used in submersible pump?

4. What is advantage of submersible pump?

5. What is mechanical efficiency?

Sl.

No.

Pressure

gauge

P

Total

Head

H

Time for 10

cm rise of

water

t

Discharge

Q

Time for 3 rev

of Energy

Meter Disc

T

Input

IP

Output

OP

Efficiency

kg/cm2 m sec x 10

-3 m

3/sec sec kW kW %

1 0.5 5.10 7.18 3.428 5.30 1.36 0.174 12.80

2 1.0 10.19 8.26 3.027 6.00 1.20 0.301 25.08

3 1.5 15.29 8.53 3.930 6.27 1.15 0.440 38.33

4 2.0 20.38 8.90 2.809 6.37 1.13 0.562 49.73

5 2.5 25.48 12.00 2.080 6.54 1.10 0.520 47.27

6 3.0 30.57 21.10 1.185 7.52 0.96 0.356 37.00

23

1.7 INFERENCES

1.8 RESULT

The performance characteristics of the given submersible pump are studied.

24

7.PERFORMANCE TEST ON RECIPROCATING PUMP

1.1 AIM: To study the performance of Reciprocating pump at constant speed.

1.2 APPARATUS REQUIRED: Reciprocating pump test rig, Stop watch

1.3 PREPARATION

1.3.1 THEORY


1. What is the working principle of reciprocating pump?

2. What is type of suction and delivery valves in reciprocating pump?

3. What do you meant by slip in reciprocating pump?

4. What do you meant by single and double acting pump?

1.4 PROCEDURE

N.B. : NEVER operate the pump with closed delivery valve. The pumping action is

continuous in this positive displacement pump. Reciprocating Pump works (pumps)

irrespective of the output or delivery. The violation leads to damage of the pipe line and

the pump. Never operate the pump above the gauge pressure of 3 kg/cm2.

1. Start the pump and run it at particular head on it.


3. Vary the flow rate (discharge) by closing the delivery valve in order to maintain certain

pressure gauge reading i.e.0.5 kg/cm2.

4. Note down pressure gauge reading (0.5 kg/cm2) and vacuum gauges readings.

5. Measure height of the pressure gauge above the vacuum gauge (Datum level)

6. Note down time taken (t) for ‗h‘ cm rise of water (10 cm) in collecting tank.

7. Note down the time taken (T) for ‗n‘ revolutions for energy meter (3 rev) disc.

8. Repeat the procedure for 0.5, 1.0, 1.5, 2.0, 2.5 kg/cm2 in the Pressure gauge reading by

closing the delivery valve.


1.5 OBSERVATIONS


1. Total head, H = [ P + (V/760) ] x 105 / ( g ) + Z (m)


V- Vacuum gauge reading in mm Hg,

Z – Datum level between Pressure gauge and Vacuum gauge



25


2. Discharge, Q = (A h )/ t (m3/sec)

Where A- Collecting tank area = l x b in m2,

t - time for 10 cm rise of water level in the collecting tank (sec)

h – Rise of water level in the collecting tank = 0.10 m

3. Output in kW, OP = g QH / 1000

4. Input in kW, IP = (‗n‘ rev of energy meter x 3600 x Efficiency of motor) / (Energy

meter constant in Rev/kW-hr x Time for n revolutions)

= (n x 3600 x m ) / (Ec x T)

Where Ec = Energymeter constant in Rev /kW – hr = 1200 rev / kWh

n = Number of revolution taken in energymeter



5. Efficiency of Pump, = (Output / Input) x 100 %

1.5.3 TABULATION:

Area of Measuring tank A : 0.3 x 0.3 m2 , Motor Efficiency m : 0.8

Energymeter Constant : 1200 Rev/kW-hr Datum, Z =0.75 m

Sl.

No.

Pressure

Gauge

reading

P

Vacuum

Gauge

reading

V

Total

Head

H

Time

for

10 cm

rise

T

Discha

rge

Q

10-4

Time for

‗n‘ rev

of EM

disc

T

Input

Power

IP

Output

Power

OP

Efficie

ncy

kg/cm2 mm Hg metres Sec m

3/sec sec kW kW %

1. 0.5 170 8.13 31.88 2.82 23.24 0.23 0.023 10.00

2. 1 170 13.22 31.10 2.90 27.90 0.26 0.038 14.62

3. 1.5 165 18.25 37.08 2.43 24.93 0.29 0.044 15.17

4. 2 160 23.28 36.46 2.47 22.40 0.32 0.056 17.50

5. 2.5 160 28.37 33.56 2.68 19.50 0.37 0.075 20.27

6 3 160 33.47 33.38 2.70 17.09 0.42 0.089 21.20

1.5.3 GRAPH: Disharge Vs head, Output, Efficiency.


1. List out the different heads used in reciprocating pump?

26

2. What is the use of air vessel?

3. Why the delivery valve should be kept open always?

4. What do you meant by indicator diagram and its use?

5. What do you meant by percentage slip and negative slip?

1.7 INFERENCES

1.8 RESULT

The performance test on reciprocating pump is completed and the performance

characteristics are studied.

27

8.PERFORMANCE TEST ON CENTRIFUGAL PUMP

1.1 Aim: To study the performance of centrifugal pump at constant speed.

1.2 Apparatus Required: Centrifugal pump test rig, Stop watch

1.3 PREPARATION

1.3.1 THEORY


1. What is the purpose of pump?

2. What do you meant by centrifugal force?

3. What is type of flow in centrifugal pump?

4. What is the use of volute casing?

5. What do you meant by priming?

1.4 PROCEDURE

N.B.: If the pump is not delivering water output , prime the pump and then start the

motor.


2. Vary the flow rate (discharge) by closing the delivery valve.

3. Note down pressure gauge reading for 0.5 kg/cm2 and vacuum gauges readings.

4. Measure height of the pressure gauge above the vacuum gauge. (Z)

5. Note down time taken (t) for ‗h‘ cm rise of water (10 cm) in collecting tank.

6. Note down the time taken (T) for ‗n‘ revolutions for energy meter(3 rev) disc.

7. Repeat the procedure for 0.5, 1.0, 1.5, 2.0, 2.5 kg/cm2 in the pressure gauge reading by

gradual closing of delivery valve.


1.5 OBSERVATIONS


1. Total head, H = [ P + (V/760) ] x 105 / ( g ) + Z (m)


V- Vacuum gauge reading in mm Hg,

Z – Datum level between Pressure gauge and Vacuum gauge



28


2. Discharge, Q = (A h )/ t (m3/sec)

Where A- Collecting tank area = l x b in m2,

t - time for 10 cm rise of water level in the collecting tank (sec)

h – Rise of water level in the collecting tank = 0.10 m

3. Output in kW, OP = g QH / 1000

4. Input in kW, IP = (‗n‘ rev of energy meter x 3600 x Efficiency of motor) / (Energy

meter constant in Rev/kW-hr x Time for n revolutions)

= (n x 3600 x m ) / (Ec x T)

Where Ec = Energymeter constant in Rev /kW – hr = 1200 rev / kWh

n = Number of revolution taken in energymeter



5. Efficiency of Pump, = (Output / Input) x 100 %

1.5.2 TABULATION

Motor Efficiency m : 0.8

Energy meter Constant = 200 rev/kWh,

Hight between the pressure gauges, Z = 500mm,

Collecting tank Area, A = 0.5 x 0.5 m2

Sl.

No.

Pressure

gauge

reading

P

Vacuum

gauge

reading

V

Time for

10cm

rise of

water

t

Time for 3

rev of

energy

meter disc

T

Head

H

Discharge

Q

x10-3

Input

power

IP

Output

power

OP

Efficie

ncy

kg/cm2 mm of hg Sec Sec m m

3/sec kW kW %

1. 0.5 560 5.5 16.50 11.5 4.5 2.62 0.51 19.50

2 1 540 5.93 15.32 18.0 4.2 2.82 0.74 26.30

3. 1.5 450 6.52 15.15 21.8 3.8 2.85 0.82 28.80

4 2 225 9.7 17.27 23.9 2.6 2.50 0.61 24.30

5 2.5 60 39 20.85 26.8 0.64 2.10 0.17 8.20

1.5.3 GRAPH: Disharge Vs head, Output, Efficiency


1. What is the energy conversion across the impeller?

29

2. List out the different heads used in centrifugal pump?

3. What do you meant by manometric head?

4. What is the pressure inside the pump casing?

5. What do you meant by manometric efficiency?

6. What do you meant by cavitation, its effects and its prevention?

1.7 INFERENCES:

1.8 RESULT

The performance test on centrifugal pump is completed and the performance

characteristics are studied.

30

9.DETERMINATION OF MINOR LOSSES DUE TO PIPE FITTINGS

1.1 AIM: To study the various losses due to the pipe fittings

1.2 APPARATUS REQUIRED: Minor losses test rig, Stopwatch

1.3 PREPARATION

1.3.2 THEORY

The various pipe fittings used in the piping applications are joints, bends, elbows,

entry, exit and sudden flow area changes (enlargement and contraction) etc. The energy

losses associated with these types of pipe fittings are termed as the minor losses due its

lesser values compared to the major loss (pipe friction) in the pipe. The loss of head is

indicated by the manometer connected across the respective pipe fitting.


1. List out the various types of pipe fittings?

2. What do you meant by minor losses?

3. What are the types of losses in pipe flow?

1.4 PROCEDURE

1. Switch on the pump. Adjust the delivery valve to a desired steady flow rate.

2. Note down the time taken for 10 cm rise of water level in the collecting tank.

3. Choose any one of the pipe fittings (4 bends, one enlargement and one contraction). e.g.

Bend-1

4. Open the levers (cocks) of respective pipe fitting to the manometer. Ensure other fitting

levers should be closed. e.g. Open the entry and exit levers of Bend-1

5. Note down the manometer head levels (e.g. h1 & h2 for bend-1)

6. Now open the other two entry and exit levers of next pipe fitting. Then close the levers of

first chosen pipe fitting. (e.g. Open the levers for Bend-2 and close the levers of Bend-1)

7. Note down the manometer for the second pipe fitting. (e.g. h1 & h2 for bend-2)

8. Repeat this procedure by opening the respective levers of a particular fitting after closing

other levers.

9. Ensure the readings taken for all pipe fittings and then switch off the pump.

1.5 OBSERVATIONS


1. Discharge, Q = (A x h ) / t ….. (m3/s)

A = Area of tank in m2

,

h = 0.10 m // Rise water level in collecting tank (m),

t = Time taken for the 10 cm rise of water in collecting tank (sec)

31

2. Velocity, V = Discharge / Area of pipe = Q/A… (m/s)

A

Where A = d2/4 , d – Dia of pipe in m

3. Actual loss of head, hf = ( h1 – h2 ) x 12.6 x 10-2

… (m)

4. Velocity loss heads for pipe fittings

Velocity head for bend and elbow hv = V2

(2g)

Velocity head for sudden enlargement hv = ( V1 – V2 )2 / (2g)

Velocity head for sudden contraction hv = 0.5 (V2)2 / (2g)

Where V2= velocity of smaller pipe

5. Loss co-efficient K = Actual loss of head / Theoretical Velocity head = hf / hv

1.5.2 TABULATION

Collecting Tank area, A = 0.6 m x 0.3 m , Pipe dia , d = 0.02 m

Pipe

fittings

Manometer

Reading

(cm)

Time for

10 cm

rise

(sec)

Discharge

(m3/s)

Velocity

(m/s)

Actual

Loss of

head, hf

(m)

Loss of head

(Theoretical)

hv

(m)

Loss co-

efficient

K = hf / hv

h1 h2 hm t Q V

Bend-1

Bend-2

Bend-3

Bend-4

Sudden

Enlarge

(20-40

mm)

Sudden

Contraction

(40-20

mm)


32

1. What is the equation for head loss due to sudden enlargement?

2. What is the equation for head loss due to sudden contraction?

3. What is the equation for head loss due to bend?

4. What is the equation for head loss at entry of pipe?

5. What is the equation for head loss at exit of pipe?

1.7 INFERENCES

1.8. RESULT

The various losses in pipe fittings are determined.

33

10. PERFORMANCE TEST ON PELTON TURBINE

1.1 Aim: To study the performance of Pelton turbine.

1.2 Apparatus Required: Pelton Turbine test rig, Stop watch, Weights & Tachometer

1.3 PREPARATION

1.3.1 THEORY


1. What are the types of hydraulic turbines?

2. What is the purpose of turbine?

3. What is the use of nozzle?

4. What is water hammer?

5. What is the purpose of surge tank?

1.4 PROCEDURE

1.4.1 SAFETY PRECAUTIONS

1. Remove any weights (loads) on the turbine shaft.

2. Ensure the closed position of the delivery valve.

3. After starting, check the functioning of cooling water supply to the turbine

4. Avoid running of turbine without cooling water to the brake drum on the shaft.

5. Keep away from the rotating shaft and avoid touching the shaft by hand or

Tachometer

6. Avoid pressure more than 2.5 kg/cm2 to the turbine for stability reasons.

7. Avoid any disturbances to the manometer tubes.

1.4.2 OPERATIONAL (PROCEDURAL) STEPS

1. Prime the pump and start it with closed gate valve. The spear in the turbine inlet and should

also be in the closed position while starting the pump in order to avoid sudden falling of water

and its impact on the turbine blades.

2. After starting the pump, Run the turbine at full spear opening by opening the spear gradually.

3. Load the turbine with the given 5 kg weights.

4. Vary the delivery pressure or pressure head acting on the turbine from 0.5 kg/cm2 to 2.5

kg/cm2 by gradual opening of the valve nearer to turbine. The incremental pressure is 0.5 kg/cm

2.

34

5. Note the following for the first Discharge pressures (P = 0.5 kg/cm2 ): Venturimeter pressure

heads (p1,p2), Turbine shaft speed (N) by torching on the turbine shaft sensor strip with the non

contact digital tachometer, Brake weight (Dead Weights plus hanger and rope weight) (W1 ) and

Spring balance reading(W2).

6. Increase the Discharge pressure by adjusting the delivery valve to 1 kg/cm2 and note down

(repeat the step-5)

7. First remove all the dead weights on the hanger. Close the delivery valve and stop the turbine.

Now switch off the power supply.

1.5 OBSERVATIONS


Input Power, IP = g Q H (W)

Where g = Specific weight of water = 9.81 kN/m3

Q = Discharge in m3/sec

Q = K √h = 3.183 x 10-3

√h (h in m )

Size of Venturimeter : 50mm and Throat Diameter : 29.58mm

Where ‗K‘ Value = (a1 a2 2g ) / (a12 – a2

2 = 3.183 x 10

-3

Where h = Venturimeter head in m of water

h = p x105/ g = (p1 – p2) x10

5/ (g) (m)

H = Supply head in m = Input total head in m

H = P x105/ (g )

Output (Brake) Power, OP = 2 N T / 60 (W)

Efficiency = (OP/IP ) x 100%

Where N = Turbine speed in RPM.,

T = W Re g = Torque in N-m

Brake drum dia D =0.2m ,

Rope dia d =0.015m

Effective radius of Brake Drum, Re = (D/2 )+d) = 0.115m

Weight of rope & hanger = 1kg.

Brake drum Net load W =(W1 + weight of rope hanger) –W2 kg = ( 5+1) – 2 = 4 kg

35

1.5.2 TABULATION

Sl

N

Pressure

gauge

reading

P

Pressure Gauge reading Venturi

-meter

Head

h

Discharg

e

Q

Weight

on

hanger

W1

Spring

balance

reading

W2

Net

Load

W

Speed

N

Inpu

t

IP

Output

OP

Effici

ency

p1

p2

P = p1-

p2

kg/cm2 kg/cm

2 m m

3/sec kg kg kg rpm W W %

1. 0.5 1.5 0.85 0.65 6.26 0.065 6 2 4 151 151 409 37

2. 1 1.4 0.8 0.6 6.12 0.062 6 2 4 487 487 787 62

3. 1.5 1.4 0.85 0.55 5.61 0.060 6 2 4 591 591 1130 52

4. 2 1.3 0.8 0.5 5.10 0.057 6 2 4 851 851 1436 59

5. 2.5 1.2 1.1 0.1 1.02 0.026 6 2 4 491 491 803 61

6.

1.5.3 GRAPH: Discharge Vs Speed, Output, Efficiency


1. What do you meant by impulse turbine?

2. How do you regulate the flow of water to the turbine?

3. What is the energy conversion from nozzle to turbine?

4. Why is braking jet used?

5. What is the spear and nozzle?

6. What is the pressure inside the turbine casing?


8. What do you meant by volumetric efficiency?

36

1.7 INFERENCES

1.8 RESULT: The performance of Pelton turbine is studied.

37

11.PERFORMANCE TEST ON FRANCIS TURBINE

Aim: To study the performance of Francis turbine.

Apparatus Required: Stop watch, Weights, tachometer

PROCEDURE

1. Prime the pump and start it with closed gate valve. The spear in the turbine inlet and should

also be in the closed position while starting the pump.

2. After starting and running the turbine at normal speed for some time, load the turbine and take

readings. Note the following: Net supply head, Discharge (pressure gauge readings), Turbine

shaft speed, Brake weight (Dead Weights plus hanger and rope weight) (1kg) and Spring balance

reading.

3. Before switching off the supply pump set, first remove all the dead weights on the hanger.

FORMULA

Input Power = g QH in kW

Where = Density of water = 1000 kg/m3

g = Acceleration due to gravity (9.81m/sec

2)

Q = Discharge in m

3/sec.

H = Supply head in meters.

2 NReW x 9.81

Brake Power =------------------- kW

60000

Output

Efficiency = ------------- x 100%

Input

Where N = Turbine speed in RPM.

T= Torque in kgm, (effective radius of the brake drum in meters (0.165m)

x The net brake load in kg.

38

FRANCIS TUBRINE

Orificemeter Head h in m of water h=(p1-p2)x 10m of water

Effective Radius of = (D/2 + t) Discharge Q = Kh (h in m of water)

Input power IP = x H x Q kW (H in m of water) Brake drum Re = 0.115m

Brake Drum net load W = (W1 + weight of rope & hanger) – W2 kg

Weight of rope & hanger = 1kg

Turbine output OP =(2 NWRe x 9.81)/ 60000 kW

Guide Vane opening = 0.5 Efficiency = (output / Input) x 100%

―K‖ value : 9.11 x10-3

Inlet diameter of Orificemeter: 80mm , Orificemeter diameter : 60 mm

Meter constant for Orificemeter: K=9.11 x10-3

h , h in m of water

Brake drum dia D=0.23m Rope Dia t = 0.015m

Input total head H in m of water = Pressure gauge reading in kg/cm2x 10

GRAPH: Discharge Vs Speed, output, Input, Efficiency

RESULT: The performance of Francis turbine is studied.

Sl.

No.

Pressu

re

gauge

readin

g

Pressure

Gauge

Reading

Orifice

meter

head

Disc

harg

e

Speed Wei

ght

on

hang

er

Sprin

g

balanc

e

readin

g

Net

load

Output

Input

Efficien

cy

P.S kg/cm2 h Q N W1 W2 W OP IP

kg/cm

2

P

1

p2 P m of

water

m3/s

ec

RPM kg kg kg kW kW %

39

FRANCIS TURBINE

Pre-Lab Questions

1. What are the types of hydraulic turbines?

2. What is the use of draft tube?

3. What is type of flow in reaction turbine?

4. What is the use of guide vanes?

Post-Lab Questions

1. What is the energy conversion across the turbine?

2. Differentiate stator and rotor vanes or blades?

3. What do you meant by runner?

4. What is the pressure inside the turbine casing?

5. What do you meant by reaction turbine?

6. List out different types of efficiency used?

7. What do you meant by brake power?

8. What do you meant by cavitation?

9. What are the methods to avoid cavitation?

40

12. PERFORMANCE TEST ON JET PUMP

Aim: To study the performance test on the jet pump at constant speed condition

Apparatus Required: Stop watch, tachometer

PROCEDURE

1. First prime the pump and start the jet pump set. While starting close the pressure gauge valve.

Then slowly open the delivery valve and adjust it to the required total head.

2. Discharge is the amount of water the pump delivers over a definite period of time. It is usually

expressed in m3/sec. The actual discharge is measured with the help of the measuring tank.

3. The power input is measured with the help of the energy meter connected in line.

4. Efficiency is the relation between the power input into the pump and the power output from

the pump. The pump output from the pump is directly proportional to the total head and

discharge. As the power input into the pump cannot be measured the power input into the motor

only is taken into account and the over all efficiency of the motor pump set is calculated.

5. If the total head (H) is measured in metres and the discharge (Q) in m3/sec, then QH gives the

output in kW. The Kilowatt input to the motor is measured with the help of the motor constant

stamped on the energy meter. Then the efficiency is calculated by dividing the output by input.

FORMULAE

Output Power = g QH in kW

Where = Density of water = 1000 kg/m3

g = Acceleration due to gravity (9.81m/sec

2)

Q = Discharge in m

3/sec.

H = Supply head in meters.

Input in kW = n x 3600

41

----------- x m

N x T

Where N = Energy meter constant = 1200 Rev /kW - hr

n = Number of revolution taken in energy meter


m= Efficiency of motor = 0.8

Efficiency = Output / Input x 100%

--------------------------------------------------------------------------------------------

Note: 1kg/cm2 = 10 meters of water.

JET PUMP TEST RIG

Size of the Pump = 32 x 25 Total head H =Pressure gauge reading in kg/cm2 x 10m

Energy meter constant N = 1200 Rev/kW-hr Measuring Area in collecting tank=0.3 x0.3m2

Discharge Q = Ah / t m3/sec Output Power = IP = QH in kW

Input in kW = n x 3600 x m Efficiency = Output / Input x 100%

N x T

TABULATION & MODEL CALCULATION:

GRAPH: Q Vs H, OP and

Sl.

No.

Pressure

gauge

Total

Head

Time for 10

cm rise

Discharge Time for 3

rev of EM

Input Output Efficiency

P H t Q T IP OP

kg/cm2 m sec x10

-4 m

3/sec sec kW kW %

1 0.5 5.10 26.5 3.396 11.81 0.610 0.0170 2.786

2 1 10.19 27.4 3.285 11.5 0.626 0.0328 5.23

3 1.5 15.29 27.8 3.237 11.0 0.655 0.0486 7.42

4 2.0 20.38 28.0 3.214 10.0 0.720 0.642 8.92

5 2.5 25.48 27.0 3.191 10.0 0.720 0.080 11.1

42

RESULT: The performance of the given jet pump is studied.

JET PUMP

Pre-Lab Questions

1. What is the purpose of jet pump?

2. What is the working principle of jet pump?

3. What are applications of jet pump?

Post-Lab Questions


2. What is the output power of the pump?

3. List out the different pressure heads used in jet pump?


5. What is overall efficiency?

43

13. IMPACT OF JET OF WATER ON VANES

Aim: To determine the coefficient of impact of water jet on different vanes

Apparatus Required: Weighing machine, Flat vane, Flat vane with oblique impact, Conical vane,

stop watch

PROCEDURE

1. Switch on the power supply.

2. Open the gate valve and note down the reading from the spring balance.

3. Then note the time for ‗H‘ metre rise in collecting tank.

4. Repeat the procedure for different gate valve openings.

5. Take readings for different vanes and nozzles.

FORMULAE

Actual discharge = Volume of collecting tank/ time taken

Area of nozzle, A = d2/4

Gravity, g = 9.81 m/s2

Theoretical force Ft = ( A V 2)/ g

Velocity V = Q/ [Cc. A]

Co-efficient of Impact = Fa / Ft

Where Fa = Actual force acting on the Disc shown from Dial Gauge.

OBSERVATIONS AND TABULATION

Measuring area in tank = 0.5 x 0.4 m2

Dia of jet = 15mm

Type of vane = Flat vane Co-efficient of Contraction, Cc = 0.97

44

Sl.

No.

Type of Vane Time for 10 cm

rise of water

(sec)

Actual

force, Fa in

kg

Theoretical

Force, Ft in

kg

Co-efficient

of impact

1

2

3

RESULT: The co-efficient of impact of the given vane = ___________

JET ON VANE APPARATUS

Pre-Lab Questions

1. What is the water jet?

2. What is the effect of water jet on vanes?

3. What do you meant by impact?

4. List out different types of vanes?

Post-Lab Questions

1. How do you compare different vanes?

2. What do you meant by co-efficient of impact?

3. How do you measure the force of the jet?


45

5. How do you measure theoretical flow rate?

14.FLOW VISUALIZATION - REYNOLDS APPARATUS

Aim: To demonstrate the flow visualization – laminar or turbulent flow.

Apparatus Required: Stop watch

THEORY

There are two different types of fluid flows laminar flow and Turbulent flow. The

velocity at which the flow changes laminar to Turbulent is called the ‗Critical Velocity‘.

REYNOLDS NUMBER(Re)

Reynolds number for pipe flow, Re = ( V D)/

Where V= Velocity of the fluid (m/s),

D= diameter of the pipe (m)

= Kinetic viscosity of the fluid (m2/s)

For water, = 1.01 x 10-6

m2/sec

Reynolds number determines whether any flow is laminar or Turbulent. Reynolds number

corresponding to transition from laminar to Turbulent flow is about 2,300.

PROCEDURE

1. Switch on the power supply. Adjust the water inflow slow by flow control valve.

2. Inject a filament of dye into the water stream by opening the value from dye tank.

3. When the flow is laminar, the colored stream of dye does not mix with the stream of water and

is apparent long the whole length of the pipe. Increase the velocity of the stream gradually by

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opening the flow control valve, to see the turbulent flow. The stream of dye begins to oscillate

and then diffused. This velocity of water in the pipe is ‗Critical Velocity‘.

REYNOLDS APPARATUS- TABULATIONS

Internal plan area of collecting tank = 0.3 x 0.3m2; Diameter of pipe d =32mm , Kinematics

viscosity of fluid (water) = 1.01 x 10-6

m2/sec

REYNOLDS APPARATUS

Sl.No. Time taken for 50mm

rise

Discharge Velocity Reynolds

number

Remarks

(Laminar/

Turbulent

flow)

t Q V Re

sec m3/sec m/s

1.

2.

3.

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Pre-Lab Questions

1. What do you meant by fluid?

2. What are the types of flow?

3. Define Reynolds number?

4. What is laminar flow?

5. What is turbulent flow?

Post-Lab Questions

1. What do you meant by stream and streak lines?

2. Mention the Reynolds no for laminar and turbulent flow?

3. What do you meant by steady and unsteady flow?

4. What do you meant by path line?

5. What do you meant by uniform and non-uniform flow?

RESULT : The flow visualization test is conducted.

Fluid Dynamics Lab Manual

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Transcript of Fluid Dynamics Lab Manual