fluid mechanics and machines laboratory manual v … · 2016-08-25 · manual v semester (10mel57)...

FLUID MECHANICS AND MACHINES LABORATORY

MANUAL

V Semester (10MEL57)

DAYANANDA SAGAR COLLEGE OF ENGINEERING

Accredited by National Assessment & Accreditation Council (NAAC) with ’A’ Grade (An Autonomous Institution affiliated to Visvesvaraya Technological University, Belagavi

& ISO 9001:2008 Certified)

MECHANICAL ENGINEERING DEPARTMENT SHAVIGE MALLESWARA HILLS , KUMARASWAMY LAYOUT

BENGALURU-560078

Name of the Student : Semester /Section : USN : Batch :

Fluid Mechanics and machines Lab 2016

ME Dept., Dayananda Sagar College of Engineering Bengaluru

Vision of the Institute

To impart quality technical education with a focus on Research and Innovation emphasizing on Development of Sustainable and Inclusive Technology for the benefit of society.

Mission of the Institute

To provide an environment that enhances creativity and Innovation in pursuit of Excellence.

To nurture teamwork in order to transform individuals as responsible leaders and entrepreneurs.

To train the students to the changing technical scenario and make them to understand the importance of Sustainable and Inclusive technologies.



FLUID MECHANICS AND MACHINES LABORATORY

MANUAL

V Semester (10MEL57)

DAYANANDA SAGAR COLLEGE OF ENGINEERING (An Autonomous Institution affiliated to Visvesvaraya Technological University, Belagavi)

MECHANICAL ENGINEERING DEPARTMENT SHAVIGE MALLESWARA HILLS

KUMARASWAMY LAYOUT BENGALURU-560078

Name of the Student : Semester /Section : USN : Batch :



VISION OF THE DEPARTMENT

To prepare world class mechanical engineers having technical competency and managerial skills driven by human values and ignite the young minds capable of addressing ever-changing global issues by research and innovation.

MISSION OF THE DEPARTMENT

To provide a platform that imparts scientific knowledge and technical

skills.

To train students to demonstrate their technical and managerial skills.

To engage students in professional activities through research, higher

education and lifelong learning.

PROGRAMME EDUCATIONAL OBJECTIVES [PEOs]

PEO1 - Graduates shall exhibit the knowledge and competency for careers in and

related to Mechanical Engineering.

PEO2 – Graduates shall exhibit the necessary skills to lead and manage

professional teams.

PEO3 - Graduates shall demonstrate their Engineering Profession by addressing

Scientific and Social challenges.

PEO4 - Graduates shall engage in Professional and Intellectual Development

through Higher Education, Research and Lifelong learning in Engineering or

related fields.

PROGRAMME SPECIFIC OUTCOMES [PSOs]

Student should practice Mechanical Engineering and apply same by the contextual

knowledge to assess societal, health, safety, legal, and cultural issues and the

consequent responsibilities relevant to the professional engineering practice.

Student should recognize, investigate, formulate and use the suitable techniques in

Mechanical Engineering to obtain solution for various problems.

Student should understand the impact of the professional engineering solutions in

societal and environmental contexts, and demonstrate the knowledge of, and need

for sustainable development.


(An Autonomous Institution affiliated to Visvesvaraya Technological University, Belagavi)

DEPARTMENT OF MECHANICAL ENGINEERING, BENGALURU-560078



FLUID MECHANICS AND MACHINES LABORATORY (SYLLABUS)

V SEMESTER B. E (ME)

Sub. Code:10MEL57 IA Marks :25

Hrs/Week :03 Exam Hrs :03

Total Hrs:42 Exam Marks :50

Course Objectives: C507.1 Shall acquire knowledge of conducting experiments in energy losses in flow

through pipes. C507.2 Hands on experience in conducting test on various flow measuring devices in

pipes flow as well as channels and its calibration. C507.3 Acquire the knowledge of conducting the performance test on various

hydraulic turbine and pumps. C507.4 Execution of the performance test on two stage reciprocating pump and air

blower.

PART - A

1. Determination of coefficient of friction of flow in a pipe. 2. Determination of minor losses in flow through pipes. 3. Determination of force developed by impact of jets on vanes. 4. Calibration of flow measuring devices a. Orifice Plate meter b. Nozzle c. Venturimeter d. V-notch 18 Hours

PART - B

5. Performance testing of Turbines a. Pelton wheel b. Francis Turbine c. Kaplan Turbines 6. Performance testing of Pumps a. Single stage / Multi stage centrifugal pumps b. Reciprocating pump 7. Performance test of a two stage Reciprocating Air Compressor 8. Performance test on an Air Blower 24 Hours



Scheme for Examination: One Question from Part A - 15 Marks (05 Write up + 10) One Question from Part B - 25 Marks (05 Write up + 20) Viva-Voce - 10 Marks

Course Outcomes:

CO1 Possible to demonstrate various energy losses in pipe flow. CO2 Possible to identify the various flow measuring devices in pipe as well as

channel flow and can demonstrate the importance of calibration. CO3 Possible to identify and demonstrate various hydraulic turbine and pumps. CO4 Possible to carry out the performance test on two stage reciprocating pump

and air blower.



DAYANANDA SAGAR COLLEGE OF ENGINEERING (An Autonomous Institution affiliated to Visvesvaraya Technological University, Belagavi)

DEPARTMENT OF MECHANICAL ENGINEERING

FLUID MECHANICS AND MACHINES LABORATORY (10MEL57)

I - CYCLE

1. Determination of coefficient of friction of flow in a pipe. 2. Determination of force developed by impact of jets on vanes. 3. Calibration of orifice plate meter. 4. Calibration of venturimeter. 5. Calibration of V-Notch.

II - CYCLE

5. Performance test on Pelton Turbine. 6. Performance test on Francis Turbine. 7. Performance test on Kaplan Turbine. 8. Performance test on Single stage centrifugal pump. 9. Performance test on Reciprocating pump.




DEPARTMENT OF MECHANICAL ENGINEERING BENGALURU – 560078

Experiment No:________ Date:____________

DO’s

Adhere and follow timings, proper dress code with appropriate foot wear.

Bags, and other personal items must be kept in designated place.

Come prepare with the viva, procedure, and other details of the experiment.

Secure long hair, loose clothing & know safety and emergency procedures.

Inspect all equipment/meters for damage prior to use.

Conduct the experiments accurately as directed by the teacher.

Immediately report any sparks/ accidents/ injuries/ any other untoward incident to the

faculty /instructor.

Handle the apparatus/meters/computers gently and with care.

In case of an emergency or accident, follow the safety procedure.

Switch OFF the power supply after completion of experiment.

DONT’s

The use of mobile/ any other personal electronic gadgets is prohibited in the laboratory.

Do not make noise in the Laboratory & do not sit on experiment table.

Do not make loose connections and avoid overlapping of wires.

Don’t switch on power supply without prior permission from the concerned staff.

Never leave the experiments while in progress.

Do not leave the Laboratory without the signature of the concerned staff in observation book.



CONTENTS

1. Determination of co-efficient of friction of flow in a pipe 10

2. Determination of minor losses in pipes 15

3. Determination of force developed by impact of jets on vanes 19

4. Calibration of orifice plate meter 24

5. Calibration of venturimeter 28

6. Calibration of v-notch 33

7. Performance testing of peloton wheel (mechanically loaded) 37

8. Performance testing of Francis turbine (mechanically loaded) 43

9. Performance testing of Kaplan turbine (mechanically loaded) 49

10. Performance testing of peloton wheel [electrically loaded] 53

11. Performance testing of Francis turbine [electrically loaded] 62

12. Performance testing of Kaplan turbine [electrically loaded] 72

13. Performance testing of centrifugal pump 83

14. Performance testing of reciprocating pump 89

15. Performance test of reciprocating air compressor [multi stage] 95

16. Performance test on air blower 100



Experiment No: 1 Date: ____________

DETERMINATION OF CO-EFFICIENT OF FRICTION OF FLOW IN A PIPE

AIM

To find the co-efficient of friction for the flow of water through the given pipes

APPARATUS

1. Pipes of different diameter

2. Stopwatch

3. Differential manometer

THEORY

A closed conduit of any cross-section used for flow of liquid is known as a pipe. In

hydraulics, generally, pipes are assumed to be running full and of circular cross-section.

Liquids flowing through pipes are connected with resistance resulting in loss of head of

energy of liquids. This resistance is of two types depending upon the velocity of flow as

viscous resistance and frictional resistance.

The viscous resistance is due to the molecular attraction between the molecules of the fluid.

At low velocities, the fluid appears to move in layers or lamina, and hence the nature of

this flow is termed laminar flow or streamline. If the velocity of the liquid is steadily

increased, at certain velocity termed the lower critical velocity the parallel bends of liquid will

become wavy. On further increasing the velocity these instabilities will increase in intensity

until a velocity corresponding to the upper critical velocity is termed transition zone. For all

further increase in velocity of flow the streamline remains in diffused state and the nature of

this type of flow is termed as turbulent. In this case the flow is restricted by the friction

between the liquid and the pipe inner surface which is known as friction resistance refer figure

1.1.

PROCEDURE

1. Open the inlet valve fully.

2. Connect the two end hoses of the differential manometer to the two ends of the pipe

0.3 meter apart of the selected diameter pipe.



3. Open the discharge control valve of the pipe by one revolution, note down the

difference in mercury level of the differential manometer

4. Note the time in seconds required to raise the level of water in the measuring tank by

10 cm.

5. Repeat the experiments for various openings of discharge control valve. Tabulate the

readings and calculate the co efficient of friction for various discharges.

Fig. 1.1 Sketch of Frictional Resistance in pipe

OBSERVATION AND CALCULATION

L = Length of the tank = 60 cm = 0.6 m

B = Breadth of the tank =50 cm=0.5 m

H =Increase of water level in measuring tank by 10 cm in‘t’ seconds

Specific gravity of mercury = 13.6

f = Co efficient of friction



L = Length of the pipe in meter

V = Velocity of water flowing through

pipe d = diameter of pipe in meter

A = area of cross section of pipe πd2

/ 4 m2

g = Acceleration due to gravity = 9.81 m/sec2

Manometer Head H = ∆ h (Sg / So – 1) *10-2

meter of water

Co- efficient of friction from Darcey-Weisbach equation is given by

Friction head hf = 4flv2

/ 2gd f = (hf * 2gd)/ 4lv2

Actual Velocity of water flowing through pipe Vact = Qact / A m/s

TABULATION

Sl.No

Dia

met

er o

f pip

e

No. o

f r

ota

tions

of

dis

char

ge

contr

ol

Manometer reading in cm of

mercury

Man

om

eter

hea

d,

H

=

∆h

(Sg/S

o

-1

)

*10

-2 m

Tim

e t

aken

fo

r r

ise

of

10 c

m o

f w

ater

‘t’

sec

h1 cm

h2 cm

∆h =

(h1-h2) cm

1

1

inch

1R

2 2R

3 3R

1

1½

inch

1R

2 2R

3 3R

1

2

inch

1R

2 2R

3 3R

Sl.No.

Qactual = (l*b*h)/t

m3/sec

Diameter of

the pipe

Vact = Qact/A

m/sec

Co–efficient of

friction

f=hf2gd /4lv2



1

1 inch

2

3

1

1½

Inch

2

3

1

2 inch

2

3

GRAPH

Draw two graphs with

1. hf vs Vact

2. f vs Qact

RESULT

Thus the Darcey-Weisbach coefficient of friction is tabulated in table below.

Tabulation of calculated values

PRECAUTIONS

1. Ensure that there is no air bubbles in the manometer.

2. Keep the time for discharge measurement sufficiently large capacity for low flows.

3. Use a sensitive manometer.

4. Ensure that there is no leakage from any pipe fittings.



VIVA QUESTIONS

1. What is meant by fluid boundary?

2. What are the practical types of flows?

3. Differentiate between Laminar and Turbulent flow. How is the type of flow is related to

Reynolds number.

4. Why there is loss of head when fluid passes through a pipeline .On what factors is

depend.

5. Explain water Hammer in pipes.




DETRMINATION OF MINOR LOSSES IN PIPES

[SUDDEN EXPANSION AND CONTRACTION]

AIM

To find the minor loss through the given pipes

APPARUTUS

The set up consists of a pipe 25mm diameter; the pipe may be about 4m long and fitted with

1. A right –angled bed or an elbow

2. A sudden expansion

3. A sudden contraction

PROCEDURE

1. Open the inlet valve, keeping the outlet valve closed.

2. Connect the manometer rubber turbine and check that there is no air bubbles

entrapped

3. Open partially the outlet valve, keeping the common inlet valve fully open

4. Allow the flow to get stabilized and then take manometer reading.

5. Measure the discharge

6. Take at least 4 readings

7. Repeat step 1 to 6 for different pipe fittings

OBSERVATIONS

Diameter of the main pipe D =

Diameter of the enlarged pipe D1 =

Area of Cross section of main pipe a =

Area of cross section of enlarged pipe a1 =

Length of the main pipe between pressure taping L=



Pip

e /

Pip

e F

itti

ng

Run

no

Discharge

measurement

Velocity of

flow in

K

Hf / hL

Vo

lum

e

of

wate

r

Co

llec

tedV

0=

(l

* b

* h

)

Tim

e t

Dis

char

ge

Q m

3/s

ec

Mai

n P

ipe

v=

Q/a

En

larg

ed p

ipe

v1=

Q/a

1

Cal

cula

ted

Mea

sure

d

Pipe bend

Sudden

enlargement

Sudden

contraction

Fig. 2.1 Sketch of sudden expansion and sudden contraction

TABULATION

Where K = f l/ D (K- is the Loss Co-efficient) K

Value for 90° Elbow is 0.9



Calculation of Co-efficient of friction of pipe

Discharge measurement Manometer reading Co-efficient of

friction

(f)

Sl.No

V0

=

Vo

lum

e of

wat

er

coll

ecte

d

lbh

t

Q =

V0

/ t

m

3 /

sec

h1 in

cm

h2 in

cm

Hf =

h1-h

2 i

n c

m

F =

sdA

2 h

f /

LQ

2

Average

(f)

1.

2.

3.

Co efficient of head loss from the graph of (h1) actual / (h1) Theoretical

Slope = K1= Constant.

Head loss Coefficient from the graph = K1 =

Nature of graph

h1 actual

h1Theoretical

Calculation for Sudden Expansion

Manometer head loss h m =h1-h2 meters.



Actual head loss = (h1) actual = h m (13.6 – 1) = meters of water

Actual Discharge Q actual = (Volume of Water collected for 10 cm rise / Time of collection) m3/

sec

Theoretical head loss = (h1) theoretical = ( V1- V2 )

2 / 2g = meters

Computed head loss Co –efficient = [(h1) actual / (h1) theoretical]

Calculation for Sudden Contraction

Manometer head loss h m =h1-h2 meters.

Actual head loss = (h1) actual = h m (13.6 – 1) = meters of water

Actual Discharge Q actual = (Volume of Water collected for 10 cm rise / Time of

collection) m3

/sec

Velocity of flow in the contracted pipe = V2 = Qa/ a2 = m / sec

Theoretical head loss = (h1) theoretical = 0.5 V2 2

/ 2g = meters Computed

head loss Co –efficient = [(h1) actual / (h1) theoretical]

RESULT

a) For abrupt enlargement of pipe section

Co efficient of head loss by direct computation = By

graphical approach =

b) For abrupt contraction op pipe section

Co efficient of head loss by direct computation = By

graphical approach =

VIVA QUESTIONS

1. What are the losses experienced by pipes, what is minor loss?

2. What is expansion and contraction in this experiment?

3. What is elbow?

4. If air bubble entrapped inside the manometer rubber tunings what will happen?




DETERMINATION OF FORCE DEVELOPED BY IMPACT OF JETS ON

VANES

AIM

To determine the impact of force of jet of water on different vanes and to find the

coefficient of impact

APPARATUS

1. Steady state water supply with provision for varying the flow rates.

2. Flow rate measuring device (collecting tank) stopwatch.

3. A nozzle of known dimension through which the water supply can be directed.

4. A flat plate, an inclined plate, a hemispherical cup and a curved vane to which water jet

can impinge

5. A device for measuring the force of the jet.

THEORY

Whenever a body produces a change in the momentum of a flowing fluid, a dynamic

force is exerted on it; According to the momentum principle the net force acting on the fluid is

equal to the time rate of change of momentum of the fluid and acts in the same direction as

that of the momentum change refer figure 3.1.



Fig 3.1 Impact of jet on vanes

PROCEDURE

1. The vane is installed (say a flat plate) & the supporting bar is leveled carefully by

adjusting the counter weight.

2. A known weight is placed on the hanger (say the least weight first)

3. The gate valve is first opened and flow is regulated till the supporting bar is perfectly

leveled.

4. The time ‘t’ sec taken to collect h cm rise of water levels (say 10 cm) in the

measuring tank is recorded using a stopwatch

5. The experiment is repeated for different loads on the weight hanger

6. The same procedure is repeated for different vanes.



OBSERVATION

Diameter of the nozzle (d) = 10 mm

Cross section area of the nozzle (a) = (π /4) *d2

mm2

Horizontal distance between the center of the vane and fulcrum x1 = 15.5 cm

Horizontal distance between the center of the hanger and the fulcrum x2 = 35.5 + 15.5 = 51cm

Length of the collecting tank 1 = 50 cm

Width of the collecting tank b = 80 cm

Area of measuring tank = 80 * 50 = 4000cm2

= 0.4 m2

Vertical distance between the tip of the nozzle and the vane y = 21 cm

Discharge Q = (l* b* h) / t m3/sec

Velocity (V) = Q / a

Where (a) = Area of the jet in m/sec

Efficiency η = Fact / Ftheory

Fact = w * g * x2/x1 Newton

Theoretical force Ftheory = ρ * a * V2

Newton

Vf = √ (V2

– 2gy)

Small Weight = 50 gms

Big Weight = 100 gms

Coefficient of impact C = Factual / Ftheoretical Efficiency = (Factual / Ftheoretical ) * 100



TABULATION

Note: Equation for F varies with shape of the target as follows:

1. Flat vane perpendicular to flow F= ρ * a * vf2

Newton

2. Flat vane at an angle to flow F= ρ * a * vf2

*sin2 Ǿ Newton

3. Semicircular Vane F = ρ * a * vf2 (1+ cos Ǿ) Newton

Sl.No

Type

of

van

e

Van

e an

gle

Ǿ

Wei

ght

added

to b

alan

ce t

he

support

ing r

od (

W)

in g

ram

s

W i

n N

ewto

n

Ris

e of

wat

er i

n 1

0cm

Tim

e ‘t

’ se

conds

Fac

t = W

* x

2/x

1 N

ewto

n

Q

act =

(l

* b

* h

)/t

m3/s

ec

Vel

oci

ty o

f je

t V

= Q

/a m

/sec

Vel

oci

ty o

f je

t at

van

es

Vf =

√(V

2 –

2gy)

Fth

eor =

ρ*a*

Vf2

New

ton

Coef

fici

ent

of

impac

t C

= F

actu

al /

Fth

eore

tica

l

Eff

icie

ncy

= (F

actu

al /

Fth

eore

tica

l )

* 1

00

1 Flat vane 90 10

2. Flat vane 90 10

3. Flat vane 90 10

4. Curved

vane

0 10

5. Curved

vane

0 10

6. Curved

vane

0 10



Fig 3.2 Line diagram showing Horizontal distances

PRECAUTIONS

1. The discharge should be changed gradually so as to imbalance the vane suddenly.

2. Before taking the readings ensure that the vane is perfectly and freely balanced.

RESULT

Thus the coefficient of impact and efficiency has been determined.

VIVA QUESTIONS

1. What is the effect of vane angle on the force excreted by the jet on the vane?

2. Theoretically, what shape of vane should be used in case of an impulse turbine?

3. What is the utility of vane?

4. What does the vane angle implies?

5. State the momentum principle? And how it works out with this experiment?

6. What is mean by co–efficient of impact of jet?

X2

X1

P Jet W Weight

Fulcrum




CALIBRATION OF ORIFICE PLATE METER

AIM

To determine the coefficient of discharge of orifice meter and to calibrate the same

APPARATUS

1. Orifice meter

2. Regulating valve

3. Measuring scale

THEORY

It is different from the venturimeter in the sense that it provides sudden change in flow

conditions instead of smooth transition provided by the venturimeter .as the liquid passes through

the orifice meter, a lot of eddies are formed and there is loss of energy due to which the

measured value of discharge, is for less and is given by

Q = Cd*a0*a1*√ (2gh)/√ ( a12-a0

2)

In which Cd is the co efficient of discharge of orifice meter, a1 is the cross sectional area of the

pipe, a0 is the cross sectional area of the orifice. The value of Cd varies from 0.6 to 0.62.

Figure shows the orifice meter installed in a pipe line connected to, an over head tank .It consists

of a flat circular plate having a circular sharp-edged hole called an orifice .The plate is fitted

concentrically with the pipe .The diameter of the orifice is half the diameter of the pipes. There

are two gauge points .One gauge point in on the upstream side of the orifice meter and other

gauge point is just near the orifice meter on the downstream side. Piezometric tapping’s leading

from the gauge point are connected to a different manometer, which indicates piezometric head.

Flow through the orifice meter is controlled by a regulating valve and is collected in a collecting

tank having a piezometric tube fixed on a measuring scale.



Fig 4.1 Schematic of streamlines in an orifice meter during fluid flow

EXPERIMENTAL PROCEDURE

1. Open the regulating valve so that the water starts following through the orifice meter. Wait

for some time so that the flow gets stabilized.

2. Remove the air bubbles, if any, entrapped in piezometric tubes.

3. Note differential monometer readings h1 and h2

4. Measure the discharge by collecting a certain volume of water in a predetermined time.

5. Repeat the step 3 and 4 for different flow rates and take at least six different sets of

observation.

6. Take another set of manometer readings foe calculation of discharge of the pipe Line for

constant out flow.

OBSERVATION

1. Diameter of the main pipe, D = 38 mm

2. Diameter of the orifice d0 = 20mm

3. Area of cross section of the pipe line a1= π D2 / 4 m

2



4. Area of cross section of the orifice a0 = π d02 / 4 m

2

5. Specific gravity of mercury S2 = 13.6

6. Specific gravity of water S1 = 1

7. Area of collecting tank A = l*b m2

8. Co – efficient of discharge Cd = 0.6 to 0.62

CALCULATION OF CO EFFICIENT OF DISCHARGE

Head loss through orifice H= h/100 (13.6 – 1) = m of water

Actual discharge through orifice meter Q actual = l*b*h/t m3/sec

Theoretical discharge through orifice meter Qtheory = a0*a1*√ (2gH)/√ (a12-a0

2)

Coefficient of discharge Cd = Qactual / Qtheory

Sl.

No

Dia

met

er o

f pip

e in

met

er

No. of

rota

tion

Manometer

reading

H =

h/1

00 (

13.6

-1

) m

of

wat

er

Tim

e ta

ken

for

10cm

ris

e of

wat

er i

n

the

coll

ecti

ng t

ank i

n ‘

t’ s

ec

Qac

tual m

3/s

econd

Qth

eory

m3/s

econd

Log (

H)

Log (

Qac

tual)

Cd =

Q

actu

al /

Qth

eory

h1

cm

h2

cm

h

cm

1R

2R

3R



GRAPH

Log H vs Log Qactual

DETERMINATION OF CALIBRATION INDEX

Qactual = k Hn where k is a0*a1*√ (2g)/√ (a1

2-a0

2)

Az

Log Qactual = Log k + n*Log H where n is the slope of graph = y/x

n = (Log Qactual - Log k)/Log H

RESULT

The coefficient of discharge of the given orifice meter Cd = ___________.

The given orifice meter has been calibrated.

VIVA QUESTIONS

1. Compare this Orifice meter with other measuring devices.

2. Differentiate orifice and Orifice meter.

3. Say few applications of Orifice- meter in industries.

4. How Orifice- meter differs from other fluid measuring equipment?




CALIBRATION OF VENTURIMETER

AIM

To find out the co-efficient of Discharge of a Venturimeter

APPARATUS

1. Venturimeter of different diameters

2. Stopwatch

3. Measuring tank

4. Differential Mercury Manometer

THEORY

Venturimeter is an instrument for measuring the quantity of fluid flowing through a pipe. The

meter, in its simplest form consists of a short converging section leading to a throat and followed

by a diverging section. The entrance and the exit diameter will be the same as that of the pipeline

to wish it is fitted. The function of the converging portion is to increase the velocity of the liquid

and lower its static pressure .A pressure difference between inlet and throat is thus developed,

which pressure difference is correlated with the flow rate. An U- Tube manometer is connected

to the tapping that are provided at the entrance and at the throat to measure the pressure

differnce.the diverging cone or diffuser serves to change the area of the stream back to the

entrance area and to convert the velocity pressure back into static pressure The co efficient of

discharge Cd lies between 0.96 to 0.98. The cd will not be truly a constant for all velocities, but

the variation is sight .The Venturimeter is not accurate for low velocities on account of the

variation of Cd Shown in figure.



Fig 5.1 Venturimeter

PROCEDURE

1. Open the inlet valve, fully. Connect the hosepipes of the differential manometer to the inlet

and Throat of the Venturimeter.

2. Open the discharge control valve of the pipe by one revolution

3. For this discharge note down the difference in mercury levels of differential manometer in

cm of mercury

4. Find out the time in seconds required to increase level of water in the measuring tank by 10

cms.

5. Repeat the experiment for second and third rotations of the discharge control valve

6. Repeat the experiment for different size Venturimeter

7. Tabulate the readings and calculate the co efficient of discharge



OBSERVATION

l = length of the measuring tank = 100 cm = 1 m

b = Breadth of the measuring tank = 50 cm = 0.5 m

h = 10 cm rise of water level in measuring tank in‘t’ seconds

d1 = Diameter of the pipe (m) = 1” = 0.0254 m

d2 = Diameter of the throat (m) = 0.6 d1 = 0.6*0.0254 m

a1 = π d12 / 4 m

2

a2 = π d22 / 4 m

2

Co efficient of discharge Cd = 0.92 to 0.98

Specific gravity of mercury = 13.6

Qtheoretical = [a1*a2* (2gH) ½

] / [a12- a2

2]1/2

m3/sec

Q actual = [(l*b*h) / t] m

3/sec


Qactual = k Hn where k is a1*a2*√ (2g)/√ (a1

2-a2

2)



From graph, log k = --------------------------



TABULATION

Sl.No

Dia

met

er o

f pip

e

Rota

tion

of

dis

char

ge

contr

ol

val

ve

Manometer reading in cm of

mercury

Man

om

eter

hea

d,

H =

h/1

00 (

13.6

-1)

m o

f w

ater

Tim

e ta

ken

fo

r ri

se

of

10

cms

of

wat

er

‘t’

sec

h1 cm h2 cm h =

(h1-h2) cm

1

I”

1R

2 2R

3 3R

1

2”

1R

2 2R

3 3R

1

3”

1R

2 2R

3 3R

Sl.No. Qactual

m3/sec

Qtheoretical

m3/sec

Log H Log Q actual Cd= Qactual/Qtheoretical

GRAPH

Log H vs Log Qactual



RESULT

Thus the Co- efficient of discharge has been determined and is __________. The given notch has

been calibrated.

VIVA QUESTIONS

1. What is venturimeter?

2. What does the calibration of venturimeter says?

3. Why did you take mercury instead of water column explain?

4. What is the major work of control valve?

5. Say few utilities of venturimeter.

6. What did you observe from this experiment?




CALIBRATION OF V-NOTCH

AIM

To find the co-efficient of Discharge of the given Notch and calibrate the same

APPARATUS

1. V-Notch

2. Stopwatch

3. Measuring tank

THEORY

A notch is a device used for measurement of discharge through an open flume. It is nothing but a

sharp edged vertical obstruction with an open –ended cut at the top, which allows the fluid to

pass through it. Then notch can be classified based on the shape of the fluid passage cut into as

rectangular, triangular, trapezoidal etc. The basic principle on which the measurement of

discharge is based is that the discharge is a function of the height of liquid flowing above the

sharp edge or crest of the notch refer figure.



Fig. 6.1 V- Notch and Rectangular Notch

PROCEDURE

1. Fill the channel with water up to the crest level and note down the initial reading H1 cm of

the hook gauge.

2. Regulate the flow of water to give maximum possible discharge without flooding the notch

&maintain steady flow

3. Note the final reading from the hook gauge H2 cm. The difference between the two gauge

readings gives the head over the notch.

4. Note the time ‘t’ sec for 10 cm rise in level water in the measuring tank



5. Repeat the experiment for various heads over V- notch

OBSERVATIONS

l = length of the tank l = 0.5 m

b=breadth of the tank b = 0.7m

h=rise of water level in measuring tank h = 0.1 m

Qactual = [Volume of water collected for 10 cm rise /Time taken ‘t’sec]

= [l*b*h / t] m3 / sec

Qtheoretical = (8/15)*(2g) 1/2

* tan (θ/2)*H5/2

m3 /sec

Angle of V-Notch θ = 900

TABULATION

Sl.No

Rota

tion o

f dis

char

ge

contr

ol

val

ve

Init

ial

hook r

eadin

g (

H1)

cm

Fin

al h

ook g

auge

read

ing

(H

2)

cm

Hea

d o

ver

notc

h

H=

H2-H

1 *

10

-2 i

n m

eter

Tim

e ta

ken

for

10 c

m r

ise

of

wat

er i

n ‘

t’ s

ec

1 1 ½ R

2 2 R

3 2 ½ R

4 3 R



Sl.No QActual Qtheoretical Log Qactual Log H Cd = [Qactual / Qtheoretical]

1

2

3

GRAPH

Plot the graph of Log H v/s Log Qactual


Qactual = k Hn where k is (8/15)*(2g)

1/2* tan (θ/2)



RESULT

Thus the results were tabulated.

PRECAUTIONS

1. As the correct discharge measurements are very important for this experiment, there should

be no leakage at any of the regulating valves

2. The width of the notch or the angle of the V notch should be carefully recorded.

3. It is very important to establish zero of the notch.

4. For measurement of h, the hook gauge reading should be taken a little distance away from

the crest of the hook.

5. Pointer gauge readings should be taken only when the water level becomes steady

VIVA QUESTIONS

1. What is notch?

2. Why a V-notch is preferred over a rectangular notch for measuring discharge?

3. What is Weir? How it is different from notch?

4. Describe a Hook gauge.

5. What are the assumptions made in arriving at the analytic expression for discharge?




PERFORMANCE TESTING OF PELTON WHEEL (MECHANICALLY LOADED)

AIM

To Study the performance of the Pelton wheel and draw the main characteristic Curves,

Operating Characteristic curves and efficiency Curves.

APPARATUS

1. Stop watch.

2. Differential manometer.

3. Tachometer

4. Pelton wheel test rig

THEORY

A turbine acts as a pump in reverse, to extract energy from a fluid system. In impulse turbine the

fluid energy first in the potential from, is next converted wholly in to the kinetic energy by

means of a free jet in one or two nozzles in the jet, the static pressure is practically that of

atmosphere in which the jet is moving.

Pelton wheel is a parallel flow impulse turbine. It operates under a high headwater and therefore

requires a comparatively less quantity of water. Water is conveyed from the reservoir to the

turbine through penstock pipes. The penstock is connected to a branch pipe fitted with a nozzle

.A powerful jet issues out of the nozzle, impinges on the buckets provided on the periphery of

wheel .in practice these buckets are usually spoon shaped. With a central ridge splitting the

impinging jet into two halves which are deflected backward .As there is no pressure variation in

flow, the fluid party fills the buckets, and the fluid remains in contact with the atmosphere .The

nozzle is provided with a spear mechanism to control the quantity of water .The actual energy

transfer from the jet to wheel is by changing the momentum of the stream. Water after impinging

its energy to the turbine is discharged in to the tailrace as shown in figure.



Fig 7.1 Pelton wheel

Fig. 7.2 Shape of Bucket

PROCEDURE

A. Under Constant speed

1. Keep the nozzle at 25 % open position.



2. Prime the centrifugal pump and start it

3. Adjust the inlet control valve to get the required speed and measure the speed (rpm) using

tachometer.

4. Note the inlet pressure gauge reading .P in Kg/cm2 at no load condition.

5. Take the reading of the manometer connected to the venturimeter. (h1 and h2 in cm of

Hg)

6. Vary the load on the turbine by putting weights in the weight hanger. Maintain the speed

constant.

7. Note down N, p, h1 and h2 for different loads on the tube.

8. Vary the nozzle openings to 50%, 75% and 100% and for each of the gate opening repeat

the experiment from step 1 to step 6.

B. Under Constant Head

1. Keep the guide vanes at 25% open position

2. Adjust the inlet control valve to get required inlet pressure p Kg/cm2 and note down inlet

pressure head H= 10 p in meters at no load condition.

3. Measure the speed, N rpm, using Tachometer.

4. Take the readings of the manometer connected to Venturimeter.

5. Vary the load on the turbine by putting weights in the weight hanger, maintain the head

constant.

6. Note down N, p, h1 and h2 for different loads on the turbine.

7. Vary the gate opening to 50%, 75%, and 100% and for each of the gate opening repeat

the experiment from step 1 to step 6.

OBSERVATIONS

Diameter of pipe d1 = 2.5 inch = 63.5mm = 0.0635 m

Diameter of throat d2 = 0.6, d1 =0.0381 m

Area of pipe a1 = π d12 / 4 m

2 = 3.1669*10

-3 m

2

Area of throat a2 = π d22 / 4 m

2 = 1.14*10

-3 m

2

Discharge through Venturimeter

Q = Cd*a1*a2 * √ (2gH) / √ (a12-a2

2) m

3 / sec



Co- efficient of Venturimeter Cd = 0.98

T= torque on brake drum = (t1+t0+t2) * 9.81*D/2 = W*D/2*9.81 Nm

t1 = Weight in the hanger in Kg

t2 = spring balance reading in Kg

t0 = Weight of the hanger in Kg = 1 Kg

Total Weight W = (t1- t2+ t0) Kg

h1 and h2 = manometer readings in cm of Hg.

Manometer head H = h/100* (13.6 - 1) m of water

D= Mean Diameter of the rope around the brake drum = 0.415 m

Output power = (π D N T * 9.81) / 60 Watts or

Output power = π (D+d) N (W – S) * 9.81) / 1000 *60 kW

Unit speed Nu = N / (H) 0.5

Unit discharge Qu = Q / (H) 0.5

Unit power Pu = P/ (H) 3/2

Specific speed Ns = (N P) 0.5

/ H 5/4

Input power Pinput = ρ g Qact H Watts

TABULATION

Sl.No

Pre

ssure

gau

ge

read

ing (p

),

Kg/

cm2

Hea

d o

f w

ater

H =

p*

10,

in m

Wei

ght

in t

1 K

g

Spri

ng W

eight

( t 2

) K

g

Tota

l W

eight

W =

( t

1- t 2

+ t

0 )

Kg

Manometer reading

of Hg

H =

h/1

00* (

13.6

- 1

) m

of

wat

er

h1

cm

h2

cm

h =

(h

1-h

2)

cm

1.

2.

3.



Qac

t =

K (

H)

0.5

m3/s

ec

Spee

d o

f pum

p N

( r

pm

)

Input

pow

er t

o p

um

p =

( ρ

g Q

act

H )

/1000 kW

Outp

ut

pow

er t

o p

um

p =

( π

DN

W)

9.8

1)

/ 60 W

atts

Eff

icie

ncy

ή =

Outp

ut

/ In

put

Spec

ific

spee

d N

s =

[N

(p)

½ ]

/ (

H)

5/4

Unit

spee

d N

u

Unit

dis

char

ge

Qu

Unit

pow

er P

u

GRAPH

a. The main characteristic cover (constant head) is plotted as follows.

Qu (Y – axis) versus Nu (X axis) for various nozzle opening

(25%, 50%, 75%, 100%)

Pu (Y – axis) versus Nu (X axis) for various nozzle opening

(25%, 50%, 75%, 100%)

ή (Y – axis) versus Nu (X axis) for various nozzle opening

(25%, 50%, 75%, 100%)

b. The opening characteristic curves (constant speed) are plotted as follows: Power (Y –axis)

versus Discharge (X- axis)

ή (Y axis versus Discharge (X- axis)



c. The constant efficiency curves asre plotted from main characteristic curves using the

discharge (y- axis) versus unit speed (x – axis) and ή (y- axis versus Unit speed (X- axis)

curves for various nozzles openings.

RESULT

Performance of the given Pelton Turbine has been studied and tabulated.

PRECAUTIONS

1. Allow the cooling water to flow along the brake drum when the turbine runs under load.

2. Keep the spear valve closed until the supply pump develops the rated head

3. Load the turbine gradually

4. Let the speed of the turbine stabilizes after each change in the load before taking readings.

5. Remove the load on the dynamometer before switching off the supply.

VIVA QUESTIONS

1. Under what conditions is a Pelton turbine suitable?

2. Why is a splitter edge provided in the buckets?

3. For maximum efficiency what should be the angle of deflection of jet, is it practically

possible to provide this angle.

4. Why is a Pelton wheel suitable for high heads only, when are multi jet Pelton wheel used?

5. What are the main and operating characteristic curves of a turbine?




PERFORMANCE TESTING OF FRANCIS TURBINE (MECHANICALLY LOADED)

AIM

To study the performance of the Francis Turbine & draw the Main characteristics curves,

opening characteristics curves and ISO-efficiency Curves.

APPARATUS

1. Turbine set up

2. Centrifugal pump

3. Manometer

4. Venturimeter

5. Pressure gauge etc

THEORY

Francis turbine is a reaction turbine in which only a part of the total head of the water is

converted into kinetic head before it enters the runner. As the water passes through the runner its

pressure changes gradually, being higher at the inlet than at the outlet. This difference in pressure

is known as the reaction pressure and is responsible for the rotation of the runner (Refer Figure)

the main parts of the Francis turbine are:

Scroll Casing: It is a spiral shaped closed passage of gradually reducing cross-sectional area,

enclosing the runner. Its function is to distribute the flow uniformly along the periphery of the

runner in such a way that the velocity remains constant at every point.

Guide mechanism: There are two main functions of the guide mechanism: to regulate the

quantity of water supplied to the runner and to adjust the direction of flow so that there is

minimum shock at the entrance to runner blades. It consists of a series of guide vanes of aerofoil

section fixed between two rings in the form of a wheel known as guide wheel. These guide vanes

are distributed evenly along the periphery of the guide wheel. These guide vanes can be rotated

about its pivot center, which is connected to a regulating ring by means of a link and lever. By



operating the regulating ring, the guide vanes can be rotated, varying the width of the flow

passage between adjacent vanes, thus altering both the flow angle as well as the quantity of flow.

Runner: The runner consists of a series of curved vanes arranged evenly around the

circumference, in the annular space between two plates. It may be cast in one piece or made of

separate steels welded together. The runner vanes are so shaped that the water enters the runner

radically at the outer periphery and leaves it axially at the inner periphery. This change in the

direction of flow from radial to axial as it passes over the curved vanes changes the angular

momentum of the fluid thereby producing a torque, which rotates the runner. The runner is keyed

to the shaft of the turbine.

Draft Tube: it is gradually expanding closed passage connecting the runner to the tailpiece. The

lower end of the draft tube is always kept submerged in water. The function of the draft tube is to

convert the high kinetic energy of flow at runner exit into pressure energy, thus increasing the

efficiency of the turbine. It also enables the turbine to be installed above the tailrace level

without any loss of head.

Fig. 8.1 Francis turbine



PROCEDURE

A. Under constant speed

1. Keep the guide vanes at 25% open position.

2. Prime the centrifugal pump and start it.

3. Adjust the inlet control value to get required speed and measure the speed using

tachometer, N rpm.

4. Note the inlet pressure gauge reading, P in Kg/cm2

at no load condition.

5. Take the readings of the manometer connected to Venturimeter. (h1 and h2 in cm of Hg).

6. Vary the load on the turbine by putting weights in the weight hanger. Maintain the speed

constant.


8. Vary the gate opening to 50%, 75% and 100% and for each of the gate opening repeat the

experiment from step 1 to step 6.

B. Under constant head

1. Keep the guide vanes at 25% open position

2. Adjust the inlet control valve to get required inlet pressure p Kg/cm2 and note down inlet

pressure head H=10p in meters at no load condition.

3. Measure the speed N rpm using tachometer.

4. Take the readings of the manometer connected to Venturimeter. (h1 and h2 in cm of Hg).

5. Vary the load on the turbine by putting weights in the weight hanger. Maintain the head

constant.


7. Vary the gate opening to 50%, 75% and 100% and for each of the gate opening repeat the

experiment from step 1 to step 6.

OBSERVATIONS

D = Mean Diameter of the brake drum with the rope around = 0.315m

T0 =head weight of the hanger = 1 kg



Manometer head = (h1-h2)*1/100*{(specific gravity of Hg/specific gravity of water)-1}= (h1-

h2)*1/100*{(13:6/1} = 0.126*(h1-h2)

Where

Specific gravity of water is 1

Specific gravity of mercury Hg is 13.6

Diameter of the pipe d1 = 2.5 inch

= 63.5 mm = 0.0635 m

Diameter of throat d2 = 0.6 d1

= 0.0381 m

Area of pipe a1 = πd12 / 4 m

2

Area of throat a2 = πd22/4 m

2

Co –efficient of venturimeter cd = 0.95

Discharge through Venturimeter = Cd*a1*a2 * √ (2gH) / √ (a12-a2

2) m

3 / sec Head constant = 0.5

*10 = 5

Where Cd = 0.9, P1= 0, P2 = 5 and K =0.0131


T = Torque on brake drum = (t0+t1-t2)*9.81*D/2* Nm =W*9.81*D/2 Nm

Output power = (2πNT) /60 = 2πN/60 (t0+t1-t2)*9.81*D/2

= (πdNW*9.81)/ 60 watts

Unit speed Nu = N/ (H) 0.5

Unit Discharge Qu = Q / (H) 0.5

Unit power pu = p/ (H) 3/2

Specific speed Ns = (NP) 0.5

/ H 5/4



TABULATION

Sl.No

Pre

ssure

gau

ge

read

ing (p

),

Kg/

cm2

Hea

d o

f w

ater

H =

p* 1

0,

in m

Wei

ght

in t

1 K

g

Spri

ng W

eight

( t 2

) K

g

Tota

l W

eight

W =

( t

1- t 2

+ t

0 )

Kg

Manometer reading

of Hg

H =

h/1

00* (

13.6

- 1

) m

of

wat

er

h1

cm

h2

cm

h =

(h

1-h

2)

cm

1.

2.

3.

Qac

t = K

(h)0

.5

m3 /

sec

Spee

d o

f pum

p

N (

Rpm

)

Input

pow

er t

o p

um

p =

(ρ*g*Q

act*

H)

Wat

ts

Outp

ut

pow

er t

o p

um

p =

[( π

DN

W)

9.8

1/6

0]

Wat

ts

Eff

icie

ncy

η =

[O

utp

ut

/ in

put

]

Spec

ific

spee

d

Ns

= [

N (

p)1

/2 ]

/ (H

) 5/4

Unit

spee

d

Nu =

N /

(sq

rt (

H)

Unit

dis

char

ge

Qu =

Q /

( s

qrt

H)

GRAPH

1. The main characteristic curves (constant head) are plotted as follows

Qu (Y – axis) versus Nu (X axis) for various gate opening (25%, 50%, 75%, 100%)

Pu (Y – axis) versus Nu (X axis) for various gate opening (25%, 50%, 75%, 100%)

ή (Y – axis) versus Nu (X axis) for various gate opening (25%, 50%, 75%, 100%)



2. The operating characteristic curves (constant speed) are plotted as follows

Power (Y-axis) Versus Discharge (X-axis)

η (Y-axis) Versus Discharge (X-axis)

3. The constant efficiency curves are plotted from main characteristic curves using the

discharge (Y-axis) versus unit speed (x-axis) and η (y-axis) Versus Unit speed (X-axis)

curves for various gate openings.

PRECAUTIONS

1. Keep the guide vanes completely closed until the supply pump develops the rated head

2. The turbine should be loaded gradually

3. Always keep the speed of the turbine within allowable limits

4. Before switching off the supply pump remove the load on the dynamometer

VIVA QUESTIONS

1. What is a turbine? What are the various types of turbines?

2. What do you mean by impulse turbine, why is an impulse turbine called on velocity turbine?

3. Describe radial flow, axial flow and mixed flow Turbines.

4. What do you mean by reaction turbine?

5. Why draft tube is used in reaction turbine?

6. Distinguish between impulse and reaction turbine.

7. Distinguish between Radial flow & Axial flow Turbine.

8. What do you mean by specific speed of a Turbine, Why it is called a type characteristic?

What are the ranges of specific speed of pelt on, Francis Kaplan Turbines?

9. Define the terms Unit power, Unit speed &Unit discharge of the Turbine.

10. How many types of reaction turbines are present? Give examples.

11. What are the functions of draft tube?

12. What is Cavitations?

13. How many types of draft tubes are there?

14. Compare fixed blade and adjustable blade reaction turbine.




PERFORMANCE TESTING OF KAPLAN TURBINE (MECHANICALLY LOADED)

AIM

To conduct the performance of Kaplan turbine at constant head and to draw the characteristic

curves.

APPARATUS

1. A centrifugal pump to supply the required head of water.

2. Kaplan turbine.

3. Pipe Work system with all necessary control valves.

4. Tachometer to measure the speed.

5. Rope brake with spring balance & weights.

6. Manometer connected to venture meter.

THEORY

Actual flow turbine is used for low heads, at high rotational speeds and large flow rates, Kaplan

turbine is an actual flow reaction turbine having small no of blades, usually from 4 to 6 closely

resembles a ship‘s propellers. Similar to Francis turbine entirely closed circuit from inlet to tile

race. The arrangement of guide ways is similar to Francis turbine. The blade angle may vary a

runner is used on which blades may be turned about their own axis. When both guide vanes a

runner blade angle may thus be varied, high efficiency can be maintained over wide range of

operating condition .The test bed for the Kaplan turbine is same as that of the Francis turbine and

is shown in Figure 9.1.



Fig 9.1 Kaplan turbine

PROCEDURE

The experimental procedure for Kaplan is same as in Francis turbine. The readings are taken for

constant head and constant head and constant speed at varies gate openings.

OBSERVATION

W = (t1+ t0- t2) Kg Total Weight

N = Speed of pump N Rpm

D= Mean diameter of brake drum with rope

T0= Dead weight of the hanger.

D1= diameter of the pipe

D2= diameter of the throat = 0.6 * d1

a1= Area of pipe = π d12 / 4 m

2

a2 = Area of throat = π d22/4m

2

Cd = Co efficient of discharge = 0.98

Discharge through venturimeter Q = Cd*a1*a2 * √ (2gH) / √ (a12-a2

2) m

3 / sec

T= Torque on brake drum = [ ( (t1+t0) – t2] *9.81*d/2 Nm.



Output power = (2πNT)/ 60

= 2πN/60*[(t1+t0) –t2] * 9.81*D/2 Watts


Unit speed = Nu = N / H) 0.5

Unit discharge = Qu = Q / (H) 0.5

Unit power = Pu = P / (H) 3/2

Specific speed = Ns = N (P/H5/4

) 0.5

TABULATION

Sl.No

Pre

ssure

gau

ge

read

ing (p

),

Kg/

cm2

Hea

d o

f w

ater

H =

p* 1

0,

in m

Wei

ght

in t

1 K

g

Spri

ng W

eight

( t 2

) K

g

Tota

l W

eight

W =

( t

1- t 2

+ t

0 )

Kg

Manometer reading

of Hg

H =

h/1

00* (

13.6

- 1

) m

of

wat

er

h1

cm

h2

cm

h =

(h

1-h

2)

cm

1.

2.

3.



Qac

t = K

( H

)0.5

Spee

d o

f pum

p N

Rpm

Input

pow

er t

o p

um

p =

( ρ

g Q

act

H )

Wat

ts

Outp

ut

pow

er t

o p

um

p=

[(

П D

NW

) 9.8

1 ]

/ 60 W

atts

Eff

icie

ncy

ή =

outp

ut/

input

Spec

ific

spee

d N

s =

[N

(p)0

.5 ]

/ (

H )

5/4

Unit

spee

d N

u

Unit

Dis

char

ge

Qu

RESULT

The performance analysis has been conducted and the various graphs have been plotted.

VIVA QUESTIONS

1. What is the specification of turbine you observed in your lab?

2. What are the difference between Kaplan Francis turbine design and application?

3. How it differs with other turbines considering capacity?

4. What is the maximum efficiency of Kaplan turbine?




PERFORMANCE TESTING OF PELTON WHEEL [ELECTRICALLY LOADED]

AIM

To study the performance of Pelton wheel and draw the different performance characteristics

curves.

APPARATUS

1. Centrifugal pump setup

2. Turbine unit

3. V-Notch

4. Stop watch

THEORY

Hydraulic turbines are the machines which use the energy of water and convert it into

mechanical energy. Thus the turbine becomes the prime mover to run the electrical generators to

produce the electricity, Viz. Hydroelectric power.

The turbines are classified as impulse and reaction types. In impulse turbine, the head of water is

completely converted into a jet, which impulses the forces on the turbine. In reaction turbine, it is

the pressure of the flowing water, which rotates the runner of the turbine. Of many types of

turbine, the Pelton wheel, most commonly used, falls into the category of turbines. While Francis

& Kaplan falls in category of impulse reaction turbines.

Normally, Pelton wheel (impulse turbine) requires high heads and low discharge, while Francis

& Kaplan (Reaction turbines) require relatively low heads and high discharge. These

corresponding heads and discharges are difficult to create in laboratory size turbine from the

limitation of the pumps availability in the market. Nevertheless, at least the performance

characteristics could be obtained within the limited facility available in the laboratories. Further,

understanding various elements associated with any particular turbine are possible with this kind

of facility.



Fig 10.1 Pelton wheel

Fig 10.2 shape of Bucket



PROCEDURE

The actual experiment setup consists of a centrifugal pump set, turbine unit, sump tank arranged

in such a way that the whole unit works on recirculation system. The centrifugal pump set

supplies the water from the sump tank to the turbine through the gate valve & notch tank with

900 V-Notch. The water after passing through the turbine unit enters the notch tank and then to

the sump tank.

Loading of the turbine is achieved by Electrical Loading (AC Alternator) connected to Lamp-

Bank Loading with switches for the measurement of Brake Power. The provision for

measurements of Turbine Speed (Digital RPM Indicator), Head on Turbine (Pressure Gauge),

and Head over the notch by Hook Gauge, are provided.



SPECIFICATIONS



OPERATION

1. Connect the supply water pump to 3 ph, 440 V, 20A electrical supply, with neutral and earth

connections and ensure the connect direction of the pump motor.

2. Keep the butterfly valve and spear valve closed.

3. Keep the electrical loading minimum.

4. Press the green button of the supply pump starter. Now the pump picks up the full speed and

becomes operational.

5. Slowly open the butterfly valve and spear valve so that the turbine rotor pick up the speed

and attains the maximum speed at full opening of the valve.

A. TO OBTAIN THE CONSTANT SPEED CHARACTERISTICS (1000 RPM)

1. Keep the butterfly valve opening at maximum.

2. For different electrical loads on the turbine, change the spear rod setting between

maximum and minimum so that the speed is held constant.

B. TO OBTAIN THE CONSTANT HEAD CHARACTERISTICS (5KG/CM2)

1. Keep the spear rod setting and butterfly valve setting at maximum

2. For different electrical loads, note the speed, head over notch and tabulate the readings.

C. TO OBTAIN THE RUNAWAY HEAD CHARACTERISTICS

1. Keep the load of the turbine at zero.

2. Keep the spear rod setting and the butterfly valve setting at maximum

NOTE: Runaway speed is also influenced by tightening the gland packing of the turbine

shaft. More it is tightened, the less the runaway speed.

D. PERFORMANCE UNDER UNIT HEAD – UNIT QUANTITIES

In order to predict the behavior of the turbine working under varying conditions and to

facilitate comparison between the performances of the turbines of the same type but having

different outputs & speeds and working under different heads, it is often convenient to

express the test results in terms of certain unit quantities.



From the output of a turbine corresponding to different working heads, it is possible to

compute the output which would be developed of the head was reduced to unit (say 1 mt);

the speed being adjusted so that the efficient remains unaffected.

OBSERVATIONS



TABULATION

Tabulation of constant speed and head characteristics

Sl.No

Spea

r val

ve

posi

tion

Hea

d o

n t

urb

ine

‘P’

in K

g/c

m2

Wat

tage

of

bulb

in a

ctio

n

Ener

gy m

eter

read

ing

Hea

d o

ver

notc

h ‘

h’

mm

No of

Revolutions

‘n’

Time in secs

‘t’

1.

2.

3.



Turb

ine

spee

d i

n R

PM

Net

hea

d o

n t

urb

ine

‘H’

in m

eter

s

Dis

char

ge

flow

‘Q

’ in

m3/s

ec

IPtu

r in

KW

BP

tur in

KW

% ή

tur

% o

f fu

ll l

oad

Tabulation of unit quantities under unit head

Net

hea

d o

n t

urb

ine

‘H’

in m

trs

Unit

spee

d ‘

Nu’

Unit

pow

er ‘

Pu’

Unit

dis

char

ge

‘Qu’

Spec

ific

spee

d ‘

Ns’

Turb

ine

effi

cien

cy %

ήtu

r

Rem

arks



GRAPH

1. Unit speed ‘Nu’ vs. Turbine efficiency

2. Unit speed ‘Nu’ vs. Unit discharge ‘Qu’

3. Unit speed ‘Nu’ vs. Unit power ‘Pu’

4. % of full load vs. efficiency of turbine

RESULT

Performance and characteristic curves of the given Pelton Turbine has been studied and results

were tabulated.

PRECAUTIONS

1. Do not start pump set if the supply voltage is less than 300V (phase to phase voltage)

2. To start and stop the supply pump, always keep gate valve (butterfly valve) closed.

3. Gradual opening and closing of the gate valve is recommended for smooth operation.

VIVA QUESTIONS

1. Under what conditions is a Pelton turbine suitable?

2. Why is a splitter edge provided in the buckets?

3. For maximum efficiency what should be the angle of deflection of jet, is it practically

possible to provide this angle.

4. Why is a Pelton wheel suitable for high heads only, when are multi jet Pelton wheel used?




PERFORMANCE TESTING OF FRANCIS TURBINE [ELECTRICALLY LOADED]

AIM

To study the performance of Francis turbine and draw the different performance characteristics

curves.

APPARATUS

1. Centrifugal pump setup

2. Turbine unit

3. Sump tank

THEORY

Hydraulic (or water) turbines are the machines which use the energy of water (hydro-power) and

convert it into mechanical energy, Thus the turbine becomes the prime mover to run the

electrical generators to produce the electricity, Viz., Hydro electric power.

The turbines are classified as Impulse and Reaction types. In impulse turbine, the head of water

is completely converted into a jet, which impulses the forces on the turbine. In reaction turbine, it

is the pressure of the water, which rotates the runner of the turbine. Of many types of turbine, the

Francis turbines falls in category of impulse reaction turbines.

The Francis turbine requires relatively low heads and high discharge. These corresponding heads

and discharges are difficult to create in laboratory size turbine from the limitation of the pumps

availability in the market. Nevertheless, at least the performance characteristics could be

obtained within the limited facility available in the laboratories. Further, understanding various

elements associated with any particular turbine are possible with this kind of facility.



The Francis turbine consists of main components such as propeller (runner) scroll casing and

draft tube. Between the scroll casing and the runner, the water turns through right angle into the

axial direction and passes through the runner and thus rotating through the runner shaft. The

runner has four blades which can be turned about their own axis so that the angle of inclination

may get adjusted while the turbine is in motion. When runner blade angles are varied, high

efficiency can be maintained over wide range of operating conditions. In other words, even at

part loads, when a low discharge is flowing through the runner, a high efficiency can be attained

in case of Kaplan Turbine, whereas this provision does not exist in Francis & Propeller turbines

where, the runner blade angles are fixed and integral with hub.

Fig 11.1 Francis turbine

PROCEDURE



supplies the water from the sump tank to the turbine through the control valve (butterfly valve)

which has the marking to meter the known quantity of water. The water after passing through the

turbine unit enters the sump tank through the draft tube.



The loading of the turbine is achieved by Electrical AC generator connected to lamp bank. The

provision for measurements of electrical energy by voltmeter and ammeter, Turbine Speed by

Digital RPM Indicator, Head on Turbine by Pressure Gauge and differential pressure across

venturimeter by inlet pressure gauge and throat pressure gauge to measure the discharge into the

turbine, are built-in on the control panel.



SPECIFICATION



OPERATION (General)

1. Connect the supply pump – motor unit to 3 ph, 440V, 30A, electrical supply with neutral and

earth connections and ensure the correct direction of pump motor unit

2. Keep the gate closed

3. Keep the electrical load at minimum, by keeping switches at ON position.

4. Set the guide vane position for a particular opening and set the crest level for zero on the

point gauge.

5. Press the green button of the supply pump started and then release

6. Slowly, open the fate so that the turbine rotor picks up the speed and attains maximum at full

opening of the gate.

a) Note down the voltage and current, speed, pressure, vacuum on the control panel, and

head over the notch using point gauge fixed on the notch tank and tabulate the results.

b) Change the position of the guide vane angles and repeat the readings. If necessary, the

gate valve (butterfly valve) also can be used for speed control.

7. Close the gate and switch OFF the supply water pump set.

8. Follow the procedure described below for taking down the reading for evaluating the

performance characteristics of the Francis turbine.

A. TO OBTAIN CONSTANT SPEED CHARACTERISTICS

1. Keep the gate opening at maximum

2. For differential electrical loads on the turbine/generator, change the guide vane angle

position so that the speed is held constant. See that the voltage does not exceed 250V to

avoid excess voltage on bulbs.

3. Reduce the gate opening settings to different positions and repeat the above step for

different speeds 1500rpm, 1000rpm and tabulate the results.

4. The above readings will be used for calculating the constant speed characteristics

a) Percentage of full load vs efficiency

b) Efficiency and BP vs Discharge characteristics

B. TO OBTAIN CONSTANT HEAD CHARACTERISTICS



1. Select the guide vane angle position

2. Keep the gate closed and start the pump

3. Slowly open the gate and set the pressure on the gauge.

4. For different electrical loads, change the gate valve position and maintain the constant

head. Finally, tabulate the results.

C. TO OBTAIN RUN-AWAY SPEED CHARACTERISTICS

1. Switch OFF the entire load on the turbine.

2. Keep guide vane angle at optimum position.

3. Slowly open the gate to maximum and note down the turbine speed. This is the runaway

speed which is maximum,













OBSERVATION



TABULATION


Sl.No

Head on turbine

Energy meter

reading

Volt

met

er r

eadin

g ‘

V’

vo

lts

Am

met

er r

eadin

g ‘

I” a

mps

Hea

d o

ver

notc

h ‘

h’

in m

m

No. of

bulb

s in

act

ion

Pressure

“P” in

kg/cm2

Vacuum

‘Pv’ in

mm of Hg

No of

revolutions

of disk ‘n’

Time

in

secs

‘t’

1.

2.

3.



Turb

ine

spee

d i

n R

PM

Net

hea

d o

n t

urb

ine

‘H’

in m

eter

s

Dis

char

ge

flow

‘Q

’ in

m3/s

ec

IPtu

r in

KW

BP

tur in

KW

% ή

tur

% o

f fu

ll l

oad


Net

hea

d o

n t

urb

ine

‘H’

in m

trs

Unit

spee

d ‘

Nu’

Unit

pow

er ‘

Pu’

Unit

dis

char

ge

‘Qu’

Spec

ific

spee

d ‘

Ns’

Turb

ine

effi

cien

cy %

ήtu

r

Rem

arks



GRAPH

1. Unit speed ‘Nu’ vs. Turbine efficiency

2. Unit speed ‘Nu’ vs. Unit discharge ‘Qu’

3. Unit speed ‘Nu’ vs. Unit power ‘Pu’

4. % of full load vs. efficiency of turbine

RESULT

Performance of the given Francis Turbine has been studied and tabulated.

VIVA QUESTIONS

1. What is a turbine? What are the various types of turbines?

2. What do you mean by impulse turbine, why is an impulse turbine called on velocity turbine?

3. Describe radial flow, axial flow and mixed flow Turbines.

4. What do you mean by reaction turbine?

5. Why draft tube is used in reaction turbine?

6. Distinguish between impulse and reaction turbine.

7. Distinguish between Radial flow & Axial flow Turbine.

8. What do you mean by specific speed of a Turbine, Why it is called a type characteristic?

What are the ranges of specific speed of pelt on, Francis Kaplan Turbines?

9. Define the terms Unit power, Unit speed &Unit discharge of the Turbine.

10. How many types of reaction turbines are present? Give examples.

11. What are the functions of draft tube?

12. What is cavitations?

13. How many types of draft tubes are there?




PERFORMANCE TESTING OF KAPLAN TURBINE [ELECTRICALLY LOADED]

AIM

To study the performance of Kaplan turbine and draw the different performance characteristics

curves.

APPARATUS

1. Propeller (runner)

2. Scroll casing

3. Draft tube

THEORY

Hydraulic (or water) turbines are the machines which use the energy of water (hydro-power) and

convert it into mechanical energy, Thus the turbine becomes the prime mover to run the

electrical generators to produce the electricity, Viz., Hydro electric power.

The turbines are classified as Impulse and Reaction types. In impulse turbine, the head of water

is completely converted into a jet, which impulses the forces on the turbine. In reaction turbine, it

is the pressure of the water, which rotates the runner of the turbine. Of many types of turbine, the

kaplan turbines falls in category of impulse reaction turbines.

The Kaplan turbine requires relatively low heads and high discharge. These corresponding heads

and discharges are difficult to create in laboratory size turbine from the limitation of the pumps

availability in the market. Nevertheless, at least the performance characteristics could be

obtained within the limited facility available in the laboratories. Further, understanding various

elements associated with any particular turbine are possible with this kind of facility.

The Kaplan turbine consists of main components such as propeller (runner) scroll casing and

draft tube. Between the scroll casing and the runner, the water turns through right angle into the



axial direction and passes through the runner and thus rotating through the runner shaft. The

runner has four blades which can be turned about their own axis so that the angle of inclination

may get adjusted while the turbine is in motion. When runner blade angles are varied, high

efficiency can be maintained over wide range of operating conditions. In other words, even at

part loads, when a low discharge is flowing through the runner, a high efficiency can be attained

in case of Kaplan Turbine, whereas this provision does not exist in Francis & Propeller turbines

where, the runner blade angles are fixed and integral with hub.

Fig 12.1 Kaplan turbine

PROCEDURE



supplies the water from the sump tank to the turbine through the control valve (butterfly valve)

which has the marking to meter the known quantity of water. The water after passing through the

guide vane of the turbine unit enters the collecting tank through the draft tube. The water then

flows back to the sump tank through the notch tank with rectangular notch for the measurement

of flow rate.

The loading of the turbine is achieved by Electrical AC generator connected to lamp bank. The

provision for measurements of electrical energy by voltmeter and ammeter, Turbine Speed by



Digital RPM Indicator, Head on Turbine by Pressure Gauge with digital indicator are built-in on

the control panel.

SPECIFICATIONS



OPERATION (General)

1. Connect the supply pump – motor unit to 3 ph, 440V, 30A, electrical supply with neutral and

earth connections and ensure the correct direction of pump motor unit

2. Keep the gate closed

3. Keep the turbine blade opening at one position

4. Keep the electrical load at minimum, by keeping switches at ON position.

5. Press the green button of the supply pump started and then release

6. Slowly, open the fate so that the turbine rotor picks up the speed and attains maximum at full

opening of the gate.

a) Note down the voltage and current, speed, pressure, vaccum on the control panel and

tabulate the results.

c) Change the position of the turbine blade angles for different openings and repeat the

readings. If necessary, the gate valve (butterfly valve) also can be used for speed control.

b) Close the gate and switch OFF the supply water pump set.

c) Follow the procedure described below for taking down the reading for evaluating the

performance characteristics of the Kaplan turbine.

A. TO OBTAIN CONSTANT SPEED CHARACTERISTICS

1. Keep the gate opening at maximum



2. For differential electrical loads on the turbine/generator, change the gate opening position

so that the speed is held constant. See that the voltage does not exceed 250V to avoid

excess voltage on bulbs.

3. Reduce the gate opening settings to different positions and repeat the above step for

different speeds 1500rpm, 1000rpm and tabulate the results.

4. The above readings will be used for calculating the constant speed characteristics

c) Percentage of full load vs. efficiency

d) Efficiency and BHP vs. Discharge characteristics

B. TO OBTAIN CONSTANT HEAD CHARACTERISTICS

1. Select the rotor blade angle position

2. Keep the gate closed and start the pump

3. Slowly open the gate and set the pressure on the gauge.

4. For different electrical loads, change the gate valve position and maintain the constant

head. Finally, tabulate the results.

C. TO OBTAIN RUN-AWAY SPEED CHARACTERISTICS

1. Switch OFF the entire load on the turbine.

2. Keep rotor blade angle at optimum position.

3. Slowly open the gate to maximum and note down the turbine speed. This is the runaway

speed which is maximum,













OBSERVATION



TABULATION


Sl.No

Head on turbine

Hea

d ov

er n

otc

h (f

low

ra

te ‘h

’ in

met

ers

Wat

tage

of

bulb

in a

ctio

n

Ener

gy

met

er

read

ing

tim

e fo

r 5

revolu

tions

in s

ecs

Pressure “P”

in kg/cm2

Vacuum ‘Pv’

in mm of Hg

1.

2.

3.



Turb

ine

spee

d i

n R

PM

Net

hea

d o

n t

urb

ine

‘H’

in m

eter

s

Dis

char

ge

flow

‘Q

’ in

m3/s

ec

IHP

hyd

BH

P h

yd

% ή

tur

% o

f fu

ll l

oad


Net

hea

d o

n t

urb

ine

‘H’

in m

trs

Unit

spee

d ‘

Nu’

Unit

pow

er ‘

Pu’

Unit

dis

char

ge

‘Qu’

Spec

ific

spee

d ‘

Ns’

Turb

ine

effi

cien

cy %

ήtu

r

Rem

arks



GRAPH

1. Unit speed ‘Nu’ vs Turbine efficiency

2. Unit speed ‘Nu’ vs Unit discharge ‘Qu’

3. Unit speed ‘Nu’ vs Unit power ‘Pu’



4. % of full load vs efficiency of turbine

5. Discharge ‘Q’ in m/sec vs efficiency and HP



RESULT

Performance of the given Francis Turbine has been studied and tabulated.

VIVA QUESTIONS

1. What is the specification of turbine you observed in your lab?

2. What are the difference between Kaplan Francis turbine design and application?

3. How it differs with other turbines considering capacity?

4. What is the maximum efficiency of Kaplan turbine?




PERFORMANCE TESTING OF CENTRIFUGAL PUMP

AIM

Determination of the Main & Operating Characteristics of a Single Stage Centrifugal Pump, by

drawing ISO-efficiency Curves

APPARATUS

1. Centrifugal pump with an Electric motor drive (constant speed)

2. Pipe work system with all the necessary control values.

3. Vacuum & Pressure gauge on pump at suction & discharge connections.

4. Stop watch

5. An energy meter to measure the input power to the motor

THEORY

A pump is a device to convert mechanical energy into hydraulic energy. The centrifugal pump is

a rotodynamic machine, which increases the pressure energy of a liquid with the help of

centrifugal action. In this type of pump the liquid is imparted a whirling motion due to the

rotation of the impeller which creates a centrifugal head or dynamic pressure. This pressure head

enables the lifting of liquid from a lower level to a higher level. The main parts of a centrifugal

pump are:

1. Suction Pipe: It is the pipe, which connects the sump from where the liquid is to be pumped

to the inlet of the pump impeller. At the lower end of the suction pipe a foot value or no

return value and a strainer are provided which are always kept immersed in the liquid in the

sump. The strainer prevents the floating debris from entering the pump, while the foot value

prevents the liquid from flowing back into the pump.

2. Delivery Pipe: It is the pipe connecting the outlet of the pump casing to the point where the

liquid is to be delivered. It is provided with a regulating value to control the flow of liquid to

be delivered by the pump.



3. Casing: It is an airtight passage provided around the impeller in order to collect liquid from

the periphery of the impeller and to transmit it to the delivery pipe at a constant velocity. The

casing may be of various types but in all of them the liquid is made to flow through a passage

of gradually increasing cross-sectional area in order to maintain a constant velocity

throughout and also to convert to high kinetic energy into pressure energy.

4. Impeller: It is in the form of a wheel having a series of curved vanes arranged evenly along

the periphery, in the annular space between two discs. The impeller has a central opening to

which the upper end of the suction pipe is connected. The impeller is mounted on a shaft,

which is rotated by an electric motor connected to it. Before starting the pump it is primed

(the suction pipe, casing of the pump and the position of the delivery pipe up to the delivery

value all are filled with the liquid to be pumped). As the impeller is rotated, it created a

forced vortex imparting a centrifugal head to the liquid. This causes the liquid to leave the

impeller at its outer circumference with high velocity and pressure, thus causing a partial

vacuum at the eye of the impeller. This vacuum sucks liquid from the sump through the

suction pipe to replace the liquid discharged from the impeller



Fig. 13.1 Single stage centrifugal pump

PROCEDURE

The performance of the pump is studied under Constant speed (main characteristic curves) and

Constant head (operating characteristic curves)

A. Under constant speed

1. The pump is primed

2. Delivery valve is kept opened

3. The belt is adjusted to obtain a particular speed for the pump. Note the speed in rpm

4. The pump is started by switching on the motor

5. Adjust the delivery control valve to get required delivery head



6. Suction pressure P1 (mm of hg) and delivery pressure P2 kg/ cm2 are noted

7. Time taken for 10 revolutions of the disc of the energy meter ‘T’ sec is noted

8. Time ‘t’sec for 10 cm rise of water in the measuring tank is noted

Operating the delivery control valve varies the head. Note P1 , P2 ,T and t in each case:- The

speed is then varied to a new value by new pair of pulleys, and experiment is repeated for

different speeds

OBSERVATION

Speed of the centrifugal pump N = 1400 rpm –constant

Energy meter constant C = 150 Rev / KWh

Motor efficiency ηmotor = 75 %

Transmission efficiency ηtrans =60%

Difference in height between the suction pressure gauge and delivery pressure gauge z = 0.75 m

Area of the collecting tank A =1.44*0.94 m2

Scale 2 div = 0.2 *10 m

The Specific speed, Ns, of the centrifugal pump is calculated from Specific speed

Ns = [N (Qact) ½]/ H

3/4Efficiency of the pump

Input power = (K/T)* (3600/C)* motor efficiency*transmission efficiency*1000 (Watts)

Output power = W Qact H = 1000 * 9.81 * Qact * H (watts)

Efficiency η = (Output / input) * 100



TABULATION

Sl

No.

Del

iver

y H

ead p

ress

ure

Hd=

P2*10 m

Su

ctio

n p

ress

ure

Hs=

p1*13.6

/1000 m

Tota

l H

ead

H=

Hs+

Hd+

Z m

Tim

e ta

ken

for

10 c

m r

ise

of

wat

er

in ‘

t’ s

ec.

Qac

tual=

(l*

b*h)/

t

m3/s

ec

Tim

e ‘T

’ se

c fo

r K

re

volu

tion

of

ener

gy m

eter

Outp

ut

pow

er (W

atts

)

Input

Pow

er (

Wat

ts)

Eff

icie

ncy

(%

)

NS

rp

m

1

2

3

4

GRAPH

The performance of the pump at constant speed may be represented by the following 3

relationships

1. Total head H against Discharge Q

2. Output power against discharge Q

3. Efficiency η against discharge Q

These relationships plotted in the graph forms are known as the operating characteristic curves.

The main characteristic curves are obtained by the following relationships obtained by keeping

the head constant

1. Total head H against speed N

2. Discharge Q against speed N

3. Power P against speed N



The ISO – efficiency curves are obtained from the operating characteristics by using the

following relationships

1. Total head H versus discharge Q

2. Efficiency η versus discharge Q

PRECAUTIONS

1. Prime the pump to remove the air completely before starting the pump

2. After each change in the valve-opening let the flow stabilize before taking readings

VIVA QUESTIONS

1. What are the different types of pumps?

2. What is a centrifugal pump?.On what basis does it work?

3. Name the different types of castings for the impeller of a Centrifugal pump.

4. What is the role of Volute chamber of a Centrifugal pump?

5. What do you mean by multi stage pumps. What are the differences between a single stage

and multi stage Centrifugal pump?

6. What is the specific speed of a Centrifugal pump, describe its use.

7. What are the advantages of Centrifugal Pumps over Reciprocating pump?

8. What is mean by priming of Centrifugal pump?

9. Give the advantage of Gear pump.

10. Distinguish between the internal gear pump and External gear pump.

11. Explain the working of Vane pump?




PERFORMANCE TESTING OF RECIPROCATING PUMP

[SINGLE STAGE SINGLE ACTING PLUNGER PUMP]

AIM

To study the performance of a single stage single acting Reciprocating pump & to draw the

characteristic curve

APPARATUS

1. Reciprocating pump with an electric motor drive.

2. Pipe work system with all necessary control valves

3. Vacuum and pressure gauge on pump suction and discharge connection

4. Measuring tank

5. Stop Watch

THEORY

The reciprocating pump is a positive displacement pump. In this type of pump the pressure is

increased by the displacement of liquid from a chamber or a cylinder due to the reciprocating

motion of a tight fitting piston. This to and fro motion of the piston creates alternatively a

vacuum pressure of a positive pressure in the cylinder due to which, Water is first sucked in and

then forced up. The reciprocating motion is imparted to the piston by means of crank and

connecting rod arrangement. The cylinder has suction and delivery pipe connected to it .The

suction pipe connects the cylinder, to a sump from which the liquid is to delivered. Both the

pipes are provided with no return valves at their ends.

The crank of the pump is rotated at a uniform speed by the driving motor, which in turn moves

the piston backwards and forwards. As the piston moves backward (suction stroke), vacuum is

created inside the cylinder which lifts the suction valve allowing the liquid from sump to enter

the cylinder under the action of atmospheric pressure .On the return stroke as the piston moves

forward, it increase the pressure of water in the cylinder which, closes the suction valve and

simultaneously lifts the delivery valve allowing the water to flow out into the delivery pipe Refer

figure.



Fig 14.1 Experiment setup (plunger pump)

PROCEDURE

The performance of the plunger pump is studied under Constant speed (Operating characteristic

curves) and Constant head (Main characteristic curves)

A. Under Constant speed

1. The required speed is selected by adjusting the belt on the appropriate pulley

2. Discharge control valve of the delivery pipe is opened fully

3. Motor is started

4. Adjust the discharge control valve to get the required delivery head indicated by the

delivery pressure gauge

5. The following readings are taken

- Speed of the pump, N rpm



- Delivery pressure head, hd kg / cm2

- Suction pressure head, hs kg/cm2

- Time ‘t’ seconds for 10 cm rise of water in the measuring tank

- Note the time ‘T’ seconds required for K revolution of energy meter disc (say 10

revolutions).

- The height difference in mountings of the suction and delivery pressure gauge, Z m

6. At different constant speed, different sets of readings are taken for various delivery heads

discharge and energy meter revolution by manipulating discharge control valve

B. Under Constant head

Keeping the delivery head constant, vary the speed by changing belt position on the pulley,

for each of this speed, the following readings are taken

- Speed of the pump, N rpm

- Delivery pressure head, hd kg / cm2

- Suction pressure head, hs kg/cm2

- Time ‘t’ seconds for 10 cm rise of water in the measuring tank

- Note the time ‘T’ seconds required for K revolution of energy meter disc (say 10

revolutions).

- At different constant delivery head hd, different sets of readings are taken by varying the

speed of the motor

OBSERVATION

Dimension of the collecting tank

Length = 26.5 cm = 0.265 m

Breadth = 26.5 cm = 0.265 m

Height = 10 cm =0.1 m

Z = 0.065 m

Speed of the pump (N) = 415 rpm

Dimension of the cylinder &piston

Diameter of the piston D= 32 mm

Area of the piston A = (π/4) D2 =8.042 * 10

-4 m

2



Stroke length, L = 32 mm = 0.032 m

Input power = (k/T) * (3600 /C) * Motor efficiency * Transmission efficiency

(K = 10 in the present experiment)

T = Tome taken for 10 rev of energy meter disc in sec

C = Energy meter constant, KW h = 800 revolutions /kWh

Take motor efficiency =80% =0.8

Transmission efficiency =86% =0.86

Output power (p) = (w * Qact *H) Watts

W= weight density (specific wt.) = ρ *9.81 N/m3

Qact = actual discharge = (l*b*h) / t m3 /sec

H = total head (hs+hd+z) m

η = (output / input)*100

% slip = ([Qtheoritical - Qactual ] / Qtheoretical ) *100

Qtheoretical = LAN / 60 m3 /sec

TABULATION

Sl.no.

Del

iver

y h

ead h

d

P1 *

10 m

eter

Suct

ion h

ead

hs

= p

2 *

10 m

eter

Tota

l hea

d

H =

[ h

s+h

d+

z]

Met

er

Tim

e ‘t

’ se

c fo

r 10

cm w

ater

ris

e

Qac

t m3 /

sec

Qth

eore

tica

l m

3/

sec

Tim

e ta

ken

fo

r 10

revs.

of

ener

gy m

eter

dis

c ‘T

’ se

c

1

2

3

4

5

6



Speed of

pump ‘N’

(Rpm)

(Constant)

Input power

of pump

Watts

(K/CT)

*1000*3600

Output

power of

pump

Watts

Efficiency

η

% of

Slip

% of volumetric

efficiency

(100 - % slip)

GRAPH

The performance curves are plotted as follows

Main characteristic Curves (Head constant Curves)

1. Qact Versus Speed

2. Total head Versus Speed

3. Output power Versus Speed

Operating characteristics curves (speed control curves)

1. Total head versus discharge

2. Output power versus discharge

3. Efficiency versus discharge

ISO–efficiency Curves

These are drawn from operating characteristic curves using the following curves

1. Head versus discharge

2. Efficiency versus discharge



RESULT

The performance of a single stage single acting Reciprocating pump has been studied.

PRECAUTIONS

1. Do not run the pump with the delivery valve completely closed

2. After each, change in the valve opening let the flow stabilize before taking readings

VIVA QUESTION

1. What is a positive displacement pump? Give some other examples of positive displacement

pumps.

2. Why the diameter of suction pipe is kept greater than that of the delivery pipe?

3. Which pump will provide a great head, centrifugal or reciprocating? Why?

4. Why is it necessary to provide a foot valve at the end of the suction pipe?

5. Compare the overall efficiencies of centrifugal and reciprocating pumps.




PERFORMANCE TEST OF RECIPROCATING AIR COMPRESSOR [MULTI STAGE]

AIM

To determine the volumetric, isothermal and polytrophic efficiency at various delivery pressure

of a multi stage air compressor.

APPARATUS

1. Multi stage Air Compressor setup

2. Pressure Gauge

3. Stop watch

4. Tachometer

5. Thermometer.

THEORY

Reciprocating compressor are displacement type of air compressor, Successive columns of air

confined in closed space where pressure is increased by reducing the volume of air space in a 2

stage reciprocating Air compressor. Movement of piston creates a partial vacuum due to low

pressure inside the cylinder .As a result, Air from atmosphere rushes in to the cylinder through

the inlet port. During the forward stroke of the piston, air gets compressed which increases the

pressure of air, which is discharged through the discharge valve. The discharge high-pressure air

no0w enters the inter cooler to reduce the temperature of the compressed air while the pressure is

kept constant .The air is then slowed in to the high –pressure cylinder where it is further

compressed and stored in the storage tank.



Fig 15.1 Multistage Reciprocating Compressor

PROCEDURE

1. Close the outlet valve of the tank properly and switch on the compressor, apply the load

operating the hand wheel.

2. The tank pressure will slowly rise indicating that the compressed air is being stored in the

tank.

3. When the tank pressure exceeds 0.5 kg /sq .cm adjust the outlet valve to maintain a tank

pressure of 0.5 kg/sq.cm.

4. Note down the manometer reading also measure the motor and compressor speed using

tachometer.

5. Note down the pressure and temperature of low-pressure cylinder and high-pressure

cylinder.

6. Take down the readings of tank pressure with different loads (Repeat the steps from 3 to 6

for each tank pressure)



SPECIFICATIONS

1. Stroke of the piston = 140 mm

2. Diameter of the Cylinder = 100 mm

3. Atmospheric temperature T1= 25 °C

4. Atmospheric pressure P1 = 1.013 bar

5. Stroke or arm length of piston (L) = 140 mm

6. Diameter of the cylinder D = 100 mm

7. Cd = 0.44

OBSERVATION

Volumetric efficiency (ήV) % = Actual Volume of Air inhaled / Stroke Volume

Actual Volume of Air inhaled (Va1) = Cd *A *sqrt (2* g*Ha) m3

/ sec

Ha = ρw*Hw /ρa meter

Hw = 5.7x10-2

, ρa = 1.293 kg/ m3

Stroke volume Vs = [(Π * D 2) / 4] * [(L * Nc) / 60] m

3 / sec

Volume of air entering to HP Cylinder (V a2) = [(P1/ P2)1/n

* Va1]

Polytropic work done (WD poly) = (n / n-1) [p1 Va1 {(p2/ p1) (n-1/n)

–1} +

P2 Va2 {(p3/ p2) (n-1/n)

–1}] kW

Input power Work done WD Ip = [(2* Π*Nm*T) / (60*1000)] kW

Isothermal work done (WDiso) = (p1 Va1) ln [(p3/ p1)] / 1000 kW

Isothermal Efficiency (ή iso) = Iso work done / Polytropic work done

Polytropic efficiency (ή po) = Polytropic work done / indicated power.

Torque (T) = Load * Arm length (L) * 9.81



TABULATION

Sl.

No

Load

Low

Pressure

Cylinder

High

pressure

cylinder

Manometer Head of

water

Spee

d o

f m

oto

r N

m i

n R

pm

Spee

d o

f co

mpre

ssor

Nc

in R

pm

Del

iver

y p

ress

ure

(t

ank

pre

ssure

) K

gf

/ cm

2

Pre

ssure

kgf

/ c

m2

P

2

Tem

per

ature

º

C

T2

P3

Kg /

cm

2

T 3

º C

h1 c

m

h2

cm

H w

met

er



Hea

d o

f ai

r in

met

er H

air

Fre

e ai

r D

eliv

ered

Vat

m

3 /

sec

Str

oke

volu

me

Vs

m3 /

sec

Input

W.d

(K

.W

)

Volu

me

of

air

ente

ring H

PC

V

a 2 in

( m

3 /

Sec

)

Poly

tro

pic

work

done

W.D

po

lytr

opic (K

W)

Isoth

erm

al w

ork

don

e

W.D

iso

ther

mal (

KW

)

ή V

in %

ή is

o i

n %

ή p

o i

n %

RESULT

Thus the Efficiencies at various delivery pressure of a multi stage air compressor were tabulated

and completed.

VIVA QUESTIONS

1. Differentiate single stage and multistage compressors?

2. What they mean about delivery pressure in aim?

3. What is the function of intercooler and LP cylinder?

4. What is the overall efficiency of multi stage compressor?

5. List the applications of the compressor in industry.




PERFORMANCE TEST ON AIR BLOWER

AIM

To study the performance of a single stage Air blower and obtain the performance

characteristics.

APPARATUS

1. Air Blower

2. Manometer

3. Venturimeter

4. Thermometer.

THEORY

Air blower is a machine that sucks air at atmospheric condition and delivers it at high velocity

and high pressure in the form of blast. Otherwise A Blower is a gas pump with relatively

moderate to high-pressure rise and moderate to high flow rate. It is used in furnaces and other

such devices where movement of air essential for their working. Example Centrifugal blowers

and squirrel cage blowers in automobile ventilation system, Furnaces, and leaf blowers.

An air blower consists of mainly an impeller and a casing. Impeller is a ring on which curved

blades are mounted which pushes air out at a high velocity energy of air to a pressure energy.



Fig 16.1 Air blower

PROCEDURE

1. Close the outlet valve completely

2. Motor is switched on to run the blower.

3. The gate valve is given 4 rotations to get quarter opening

4. Voltmeter and wattmeter readings are noted down.

5. Suction Head, Delivery Head and venturimeter readings are noted down

6. Inlet T1 and Outlet T2 temperatures are measured using Thermometer

7. Repeat the above procedure 3 more times with 4 rotations each time and thus a total of 16

rotations and hence 1 complete opening

8. Tabulate the readings

9. Use the formulas that are listed below to calculate the input power, Output power, Overall

Efficiency and isentropic efficiency.



OBSERVATION

Venturi head hair = (ρhg * hv) / ρa in meter

Discharge of Air Q = [Cd * a1*a2*sqrt (2 g*hair)] / sqrt (a12-a2

2) m

3 / Sec

Head of blower HB = [ρ w * (Hs+Hd)] / ρ air in meter

Absolute Suction pressure p1= P atm – (W * Hs) N/m2

Delivery pressure P2 =Patm- (W*Hd) N/m2

Temperature of isentropic compression T2’ = T1 * (P2/ P1)

( γ – 1) / γ

Input work done = (V* I Cos Ø / η motor *1000) KW (Where Cos Ø =1)

Output work done = [(ρair *g) * Hb * Q] / 1000 kW

Overall efficiency = (O.P. Work done) / I .p work done) * 100

Isentropic efficiency = (T2’- T1) / (T2 – T1)

Efficiency of motor ηmotor = 85%

Density of air ρair = 1.013 kg / m3

Co efficient of discharge Cd = 0.21

Isentropic constant γ =

1.4

Density of water ρwater = 1000 kg / m3

TABULATION

Serial no. 1 2 3 4

Gate opening

¼ =

4

rev

½=

8

rev

¾ =

12

rev

1=

16

rev

Suction head

h1 m

h2 m

Hs = ( h1- h2) m

Delivery head

h1 m

h2 m

Hd = ( h1~h2) m

Venturi Head

h1 m

h2 m

Hv = (h1~h2)m



Inlet Temperature,

T1 (°C)

Outlet temperature,

T2 (°C)

Voltage volts (v)

Current, ampere (A)

Input to the blower,

IP (kW)

Output from the blower OP

(kW)

Overall efficiency

η ov %

Isentropic efficiency ηisen %

RESULT

Thus the performance of single stage air blower has been tabulated and its performance

characteristics were drawn.

VIVA QUESTIONS

1. What are blowers how it differs from fans?

2. What is mean by single stage in the blower?

3. Is the blower blade design varies from others?

4. What is impeller casing?



REFERENCES

1. R.K. Bansal, A Textbook of Fluid Mechanics and Hydraulic Machines, Lakshmi

Publishers, Ninth edition.

2. Jagdish Lal, Hydraulic Machines, Metropolitan Book Co. Ltd New Delhi, Ninth edition.

3. Rajput, Fluid Mechanics and Hydraulic Machines, S Chand and Company Limited, Tenth

edition.

4. P.N. Modi and S.M. Seth, Hydraulics and Fluid Mechanics Including Hydraulic

Machines, Standard Book House Delhi, Twentieth edition.

5. P. Balachandran, Engineering Fluid Mechanics, PHI Learning Pvt. Ltd.2012.



DAYANANDA SAGAR COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING, BENGALURU-560078

CONTINUAL EVALUATION FORMAT


(2016-2017)

Semester /Section : Batch :

S

No

.

USN student Name Expt. No: 1 Expt. No:2 Expt. No:3 Expt. No:4

Date: Date: Date: Date: Viva

(05)

Record

(10)

Total

(15)

viva

(05)

Record

(10)

Total

(15)

Viva

(05)

Record

(10)

Total

(15)

Viva

(05)

Record

(10)

Total

(15)

Faculty Signature With Date

Name of the Faculty In charge (1) (2) (3)

Note:

(1) Viva questions to be asked w.r.t the current experiment of the particular week.

(2) The above same page format is used for next set of experiments i.e. 5, 6,….expts.

(3) Separate sheets must be used for different batches.



DAYANANDA SAGAR COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING, BENGALURU-560078

FINAL IA MARKS FORMAT


Year:

Semester /Section : Batch :

SN USN Name Of The Student

Continual Evaluation

Marks (15)

IA Test Marks (10)

Final Marks (25)

Signature of Student

fluid mechanics and machines laboratory manual v … · 2016-08-25 · manual v semester (10mel57)...

Documents