Hydraulic Engineering Lab Manual

5/17/2018 Hydraulic Engineering Lab Manual

1/27

Ex.No

Date

AIM:

:

:CENTRIFUGAL PUMP

To study the operating characteristics of centrifugal pump.

APPARATUS REQUIRED:

1) Centrifugal pump test rig.

2) Stop watch.

3) Metre scale.

FORMULA:

1. Total head (H) :H = Hs+Hd+Hc

Where,

Hs Suction head (m)

Hd Delivery head (m)Hc Correction head (m) (0.38m)

2. Suction head Hs(m) of water:

Hs = Hs(Hg) x SHg

SwWhere,

Hs(Hg) Suction head in mercury column (m)

SHg Specific gravity of mercury (13.6)

Sw Specific gravity of water (1)

3. Delivery head Hd(m) of water:

Hd =

Pd

W

Where,

Pd Delivery pressure (Kg/cm2).

W Specific weight of water (1000Kg/m3).

4. Discharge (Q):

Q = lby

t1


2/27

Where,

L, b Dimensions of collecting tank (m)Y Dimensions of water in tank (m)

t1 Time for y rise of water (s).

5. Input power (I/P):

I/P = 3600N

Ect2

Where,

N number of revolutions in energy (m)

Ec Energy meter constant (rev/ kw) (150 rev/kw)

t2 Time for n revolutions (s).

6. Output Power (Q/P):

O/P = QWH

1000

Where,

Q Discharge (m3/s)H Total head (m)

W Specific weight of water (9810 N/m3).

7. Efficiency :

= O/P x 100

I/P

THEORY:

The centrifugal pumps are classified into rotodynamic pump where the pressure is

developed which enables lighter liquid from lower to higher levels. Basic principle is that

when mass of certain liquid is made to rotate by an interfere force is made head isimpressed, which enables it to a high level. If more, then the higher level of pump is

ensured in addition to liquid as it passes through impeller. Its angular momentum changes

which also results in increase of pressure of liquid.


3/27

PROCEDURE:

1. Area of collecting tank us found and difference between level of suction and

delivery are measured.

2. Priming the pump is necessary.3. Open the delivery value fully and search on pump.

4. Delivery valued is closed gradually till delivery head is developed high in valued.

5. The delivery value is closed gradually.6. Tabulate observed readings after the experiment.

RESULT:

The experiment is studied and

(i)

(ii)

Maximum efficiency obtained:

Corresponding input power :(iii) Corresponding Discharge:

(iv) Corresponding total head:

TABULATI

ONS:

Sl.No Suction

Pressu

re

Hs(H

g)

Delivery

Pressure

Pd

Time for

10cm

rise of water

t1

Time for

5

Revolutio

n

t2

Suction

Head(Hs)

Deliver

y

Head(Hd)

Total

HeadH

Discharg

e

(Q)

I/P O/P Effi

1

2

3

4

mm of Hg Kg/cm2 sec sec m m m m3/s Kw

Kw

%


4/27

SYSTEM DETAILS:

Length of collecting tank, l =

Breadth of collecting tank, b =

Energy meter

constant

Correction head

=

=

Ex.No

Date

AIM:

:

:RECIPROCATING PUMP

To study the operating characteristics of reciprocating pump.

APPARATUS REQUIRED:

1. Reciprocating pumps

2. Test rig3. Stop watch

4. Metre scale

FORMULA:

(i) Total head (H) m of water:

H = Hs +Hd+Hc

Where,

Hs Suction head (m)

Hd Delivery head (m)

Hc Correction head (m) (0.43m)

ii) Suction Head:

Hs = Hs(Hg) x SHg

SwWhere,

Hs (Hg) Suction head in Hg columns (mm of Hg)

SHg Specific gravity of Hg (13.6)Sw Specific gravity of water (1)

iii) Delivery head:


5/27

Hd = Pd/wWhere,

Pd delivery pressure (Kg/cm2)

W Specific gravity of water (1000kg/m3).


6/27

iv) Discharge:

Q = (lby)/t1

Where,

L length of the collecting tank (m)

B breadth of the collecting tank (m)

Y rise of water in collecting tank (m)t1 time for y m rise of water (s)

(v) Input power:

I/P = 3600N

Ect2Where,

N no of revolutions

Fc Energy meter constant (rev/kwh) (1500rev/kw)

t2 time for n revolutions(s)

(vi)Output power :

O/P = WQH Watts

(Or)

= WQH KW1000

Where,

Q Discharge (m3/s)

W Specific weight of water (9810N/m3)H Total head (m)

viii) Efficiency:

= O/P X 100

I/P

THEORY:

The pump is driven by from an electric motor and speed is reduced through belts

and reducing gear systems. The pump consists of a cylinder in which piston works

forward and backward. This movement causes positive and negative in cylinder and this

rises the water.


7/27

PROCEDU0RE:

1. The details regarding the pump, motor and system are noted, the size of

2. collecting tank energy meter is constant

3. Keeping the delivery tube value fully open the motor is started under thiscondition following vacuum gauge reading, pressure gauge reading, pressure

gauge reading, time for 10cm rise in time for revolutions of energy meter

4. Repeat the observations for at least five different head by mounting the tube.

5. Necessary observations are more keeping the delivery tube value full.

RESULT:

1. Maximum efficiency obtained

2. Corresponding discharge

3. Input power

4. Corresponding total head of water

=

=

=

=

TABULATIONS:

Delivery

Suction

Pressure

Pressure

Pd

Hs(Hg)

Kg/cm2 mm of

Hg

SYS

TEM

DET

AILS

:

Size

of

colle

cting

tank

E

n

e

r

g

y

m

e

t

e

r

c

o

n

s

t

a

n

t

C

o

r

r

e

c

t

io

n

he

ad

=

=

=

Suction

Head

Hs

m

Deliv

ery

Hea

d

Hd

m

Total

Head

H

m

Time f

10cm

riset1sec


8/27

Discharge

Q

m

3/s

Time

for

5

revolutiont2

secInput

power

I/P

Kw

Output

power

O/P

Kw

Efficie

ncy

%

Ex.No

Date

AIM:

:

:VENTURIMETER

To determine the coefficient of discharge of the Venturimeter

APPARATUS REQUIRED:

1) Venturimeter with manometer

2) Stop watch3) Collecting tank

4) Supply pump

FORMULA:

1) Drop in head across meter:

H = (H1H2)sm-sw (m)

Sw

Where,

H1,H2 manometer readings (m)Sm Specific gravity of mercury (13.6)

Sw Specific gravity of water (1)

2. Theroitical discharge (Qth):

Qth = a1a22gh (m3/s)

a12 a22Where,

a1 cross sectional area of pipe (m2)

a2 cross sectional are of throat (m2)

D1D2 diameter of pipe (25mm) and throat (11mm) (m)h drop in head across meter (m)

3. Actual discharge (Qact):

Qact = lby (m3/s)

T


9/27

Where,

L length of collecting tank (m) (0.5m)

B breadth of collecting tank (m) (0.5m)Y rise of water level in tank (m) (0.1m)

T time for y m rise in tank (s)


10/27

4. Co-efficient of Discharge:

Cd = Qact / Qth

Where,

Qact Actual discharge (m3/s)Qth Theoritical discharge (m3/s)

THEORY:Venturimeter is a device which works on the principle of Bernoull is equation. It

is used for measuring the rate of flow of fluid through a pipe. It consists of these parts.

1. A short converging part.

2. Throat3. Diverging part

A U-tube manometer is connected to the pipe and through which shows the head

difference between them. There will not be any datum head H the water is horizontal.

Hence the pressure head is equal to the velocity head. The main principle involved is thatthe pressure at throat is maximum due to decreasing cross section which is measured by

using manometer. Thus we measure discharge as well as its co-efficient.

PROCEDURE:

1. Check whether all the joints are leak proof and water tight.

2. Close all the pipes with cocks in the pressure feed pipes and manometer toprevent damage and over loading of the manometer.

3. Open the inlet value of the pipe.

4. Switch on the pump and adjust and the control value to allow the meter toflow through Venturimeter.

5. Open the down stream and upstream cocks that connect the manometer to theVenturimeter for which the co-efficient of discharge is to be calculated.

6. Prime the manometer properly.7. Adjust the control value to maintain the flow and for the deserved rate of

flow.

8. Measure the manometer head to find the venture discharge.9. Measure the time taken for 10mm rise in the collecting tank to find the actual

discharge.

10. Calculate the co-efficient of discharge and repeat the procedure for thedifferent flow rates.

RESULT:

The co-efficient of discharge for the Venturimeter is found out and the necessary

graph is plotted.

(i)

(ii)

From the table Cd =

From the graph Cd =

TABU

LATI

ONS:

S.

N

o

Manometer

Readings

H

H


11/27

Drop in head

across the meterH

H Time

for

10cm

rise in

Tank T

Theoritic

al

dischargeQth

Actual

Discharg

eQact

Co-

efficient of

discharge

1

2

3

4

x10-2m x10-2m x10-2m m m sec x m3/s x m3/s No

SYSTEM DETAILS:

Length of collecting tank

(l)

Breadth of collecting tank

(b)

Area of tank

Inlet diameter, d1

Throat diameter d2

A1 =

A2 =

=

=

=

=

=

Ex.No

Date

AIM:

:

:ORIFICE METER

To determine the co-efficient of discharge of the orifice meter.

APPARATUS REQUIRED:


12/27

1) Orifice meter

2) Manometer

3) Stop watch4) Collecting tank

5) Supply pump

FORMULA:

1. Drop in head across meter (H):

H = (h1-h2) (Sm-Sw) (m)

Sw

Where,

Sm Specific gravity of mercury (13.6)Sw Specific gravity of water (1)

H1,H2 Manometer readings (m)

2. Theoritical discharge (Qth):

Qth = a1a22gh (m3/s)

a12 a22

Where,

a1 Cross sectional area of pipe (m2)

a2 Cross sectional area of orifice (m2)h Drop in head a cross meter (m)

3. Actual discharge (Qact):

Qact = lby/T (m3/s)

Where,L length of collecting tank (m) (0.5m)

B breadth of collecting tank (m) (0.5m)y rise of water in collecting tank (m) (10cm)T time for y m rise of water (s)


13/27

4. Co-efficient of discharge (Cd):

Cd = Qact/Qth

Where,

Qact Actual discharge (m3/s)

Qth Theoritical discharge (m3/s)

THEORY:

Orifice meter is a device used for measuring the rate of flow of a fluid through the

pipe. It works on the same principle as that of Venturimeter. It consists of a flat circular

plat having a circular sharp edge hole called orifice, concentric with the pipe. The orifice

diameter is 0.5 times the diameter of the pipe.

PROCEDURE:

1. Check whether all the joints are leak proof and water tight.

2. Close all the cocks in the pressure feed pipes and manometer to prevent

damage and overloading of the manometer.

3. Open the inlet value of the pipe.4. Switch on the pump and adjust the control value to allow the water to flow

through orifice meter

5. Open the down stream and upstream cocks that connect the manometer to theorifice meter for which the co-efficient of discharge is to be calculated.

6. Prime the manometer properly.7. Adjust the control value to maintain the flow and for the desired rate of flow

8. Measure the manometer head to find the orifice discharge.9. Measure the time taken for the 10mm rise in the collecting tank to find the

actual discharge.

10. Calculate the co-efficient of discharge and repeat the procedure for thedifferent flow rates.

RESULT:

The co-efficient of discharge for the orifice meter is found out and the necessary

graph is plotted:

From the table Cd =From the graph Cd=


14/27

TABULATIONS:

S. No

H1

Manometer Readings

H2 H1H2

Drop in head

across the meter

(H)

H Time for 10cmrise in Tank T

Theoritical

discharge Qth

Actual

Discharge

Qact

Co-efficient

of discharge

1

2

3

4

x10-2m x10-2m x10-2m m m sec x m3/s X m3/s

SYSTEM DETAILS:

Length of collecting tank (l) =

Breadth of collecting tank (b) =

Diameter of pipe (d1)

Diameter of throat (d2)

A1= d12

4

A2 = d22

4

=

=

Ex.No

Date

AIM:

:

:


15/27

KAPLAN TURBINE

To study the characteristics of Kaplan turbine under constant head condition.

APPARATUS REQUIRED:

1. Kaplan turbine

2. Tacheometer

FORMULA:

1. Discharge (Q):

Q = Cd a1a22gh (m3/s)

a12-a22

Where,

Cd Co-efficient of discharge of Venturimeter (0.98)

a1 area of inlet section (m2)

a2 area of outlet section (m2)

h Venturimeter head (m) (P1- P2)/ w

P1, P2 Pressure in inlet and throat respectively (kg/cm2)

w Specific weight of water (1000kg/m3)

2. Input power (I/P)

I/P = W x Q x H

Where,

Watts

W Specific weight of water (9810 N/m3)

Q Discharge (m3/s)

H Head of water at inlet of turbine (m)- (Pd*10)

3. Output power (O/P):

O/P = DN x T Watts

Where, 60N Speed of turbine (rpm)

D Brake down diameter (m)

T (T1-T2+T0)* 9.81 (N)T1 load applied in hanger (kg)

T2 Spring load (kg)

T0 Weight of hanger (0.75kg)


16/27


17/27

4. Efficiency of turbine (n):

N = O/P x 100 %

I/P

5. Specific speed (Ns):Ns = Np rpm

(H)5/4

Where,

N Speed or maximum efficiency (rpm)P Output power corresponding to maximum efficiency (kw)

H Head and inlet of turbine (m)

DESCRIPTION:

Kaplan turbine consists of series of disc of buckets fixed around the periphery ofcircular disc or circular where called runner. The runner mounted on shaft water issupplied by a pump through pipe. The other end of pipe in fitted with nozzle. The amount

of water flowing out of nozzle is controlled by a spear. The difference in pressure is

measured by differential manometer. The rate of flow through the pipe is measured by aVenturimeter. The water is discharged through a draft tube in total race.

PROCEDURE:

1. Prime the pump with water and start the pump.

2. Gradually open the delivery value.

3. Observe speed and wheel using tachometer.4. Observe the reading of s1, s2of correspondingly to find fluid level in meter.5. Adjust the load on brake drum and note down the speed of turbine using

tachometer and spring balance reading

Repeat the above steps for certain number of reading.

RESULT:

(i)Maximum efficiency =

(ii) Corresponding out put power =(iii) Corresponding input power

(iv) Specific speed

=

=

TABULATIO

NS:

S.N

o

S

p

eed

of

turbinerpm N

Load Applied

(T)Kg

Spring

Load,

T2


18/27

T =

Net weight

of Brake

down

T

x

9

.

8

1

Inl

et

Pr

es

su

rePressure in

Venturimeter

P1x 104 P2x 104

Input

Power

I/P

Output

Power

O/P

Effi

enc

N

1

2

3

4

5

SYSTEMDETAILS:

Diameter of brake

drum

Diameter of pipe

inlet

Diameter of pipethroat

Pressure head inlet

Cd =

To - Wt of hanger

Area of inlet

Area of throat

=

==

=

=

=

=

Kg (T1T0)+T

0

Kg

N head x 104

(Pd)

kg/m2

kg/m2 kg/m2 W W %

Ex.No

Date

AIM:

:

:FLOW THROUGH ORIFICE


19/27

To determine the hydraulic co-efficient Cd,for the given orifice by Varying head method and to co

Cd with constant head method.

APPARATUS REQUIRED:

1. Orifice

2. Metre scale3. Stop watch

4. Collecting tank

5. Horizontal scale & vertical scale.

DESCRIPTION:

The experimental setup consists of an orifice tank at which the orifice is fixed at

the bottom of the tank. A piezometer tube is fixed in the orifice tank to measure the head

of water. Two scales one vertical and other horizontal are fixed in front of the orifice tomeasure the level of water jet flowing. A pipe is provided through which water flows into

the collecting tank in which a piezometer tube is fixed to find the size of water level. A

electric motor driven pump is used to pump water to one orifice tank. The collecting tank

consists if an outlet tube provided with a value which allows water into a pump which is

recirculated. Orifice is a small opening of any cross-section (much as circular, triangular,

rectangular etc) on the side or at bottom of a tank through which a fluid is flowing.

Orifice are used for measuring the rate of flow of fluid. The liquid flowing through the

orifice forms a jet of liquid whose area of cross-section is less than that of orifice. The

area of jet of fluid goes on decreasing and at a section cc the area is minimum. Thus

section is approximately at a distance of half of diameter of the orifice. At this section,the streamlines are straight and parallel to each other and perpendicular to the plane of

orifice. Thus section is called Vena-contracta. Beyond this section, the jet diverges and is

attracted in this downward direction by the gravity.

FORMULA USED:

Theoritical discharge =

=

area of orifice X Theortical Velocity

ax2gh

V=2gh

Actual discharge

Qa =Ay

tA area of collecting tank

y Rise of water in collecting tank

t time taken for 10 cm rise.

Co-efficient of discharge

Cd = Qact

Qth


20/27

Varying Head:

Cd=2A(H1-H2) 2g at

Where ,

A-area of collecting tanka- area of orificeg-acceleration due to gravity

H1-initial head in orifice tankH2-final head in orifice tankt-time required for descending the liquid from H1 to H2

PROCEDURE:

The motor is switched on first and cdvalue is found by varying method. In this method the value Hfixed at certain point. Then the water in the tank is raised to certain level. H1ie by regulating the ivalue Note the time taken for the fall in water level from H1 to H2. Then very H1 distance by keepvalue as constant. Note the diameter of the orifice and are of the tank. In the case of constant had the height h is kept constant and the time taken for 10 cm rise in the collecting tank is found out.vary the height and find the corresponding time. After taking 5 readings switch off the moter

GRAPH:

A graph is plotted by taking H along x-axis and Cd, Cv, Cc, along y-axis.


21/27

RESULT:

The hydraulic coefficient of orifice is

Co-efficient of discharge Cd by Varying head method

Co-efficient of discharge Cd by constant head method

TABULATION:

S.No H1 H=H1-H0cm Cm

Ave

rag

e

Cv

=

Ave

rag

e

Cc

=

A

v

e

r

a

g

e

C

d

=

Qth

(m3/sec)x10-3

Time for

10cm

risecm

Qact

(m3/s

ec)x1

0-4

Cd

Ex.No

Date

:

:

DETERMINATION OF COEFFICIENT OF DISCHARGE FOR THE GIVEN

ORIFICE- BY VARYING HEAD METHOD

AIM:

To determine the co-efficient of discharge of mouthpiece by varying headmethod and to compare Cd with the constant head method.

APPARATUS REQUIRED:

1. Mouth piece

2. Meter scale

3. Stop watch

FORMULA:

Cd = 2A[H1-H2]2g at

A area of collecting tank


22/27

a - area of orificeg acceleration due to gravity.

H1 Initeal head in orifice tank

H2 Final head in orifice tankcd - Coefficient of discharget time required for descending liquid

from H1to H2

CONSTANT HEAD METHOD:

Qth = a2gha Aea of mouth piece

h Head max.

Qact = Ay

t

A Area of collecting tank

t - Time for 10cm rise of liquid

Cd Qact

Qth


23/27

DESCRIPTION:

The experiment consists of main tank from which water is pumped by motor to

the mouth piece tank through the inlet value. The inlet value is used to regulate the water

flow. A scale is present at the side of the tank to know the amount of water in the tank. Acollecting tank is present and a scale is also present to find out 10cm size of water in the

collecting tank.

PROCEDURE:

1. The motor is notched on first and Cd value is found by varying head method. In

this method the value H2is fixed at certain point.

2. Then the water in the tank is raised to certain level H1(ie) by regulating the inlet

value note the time taken for the fall in the water level from H1to H2.

3. Then vary H1distance by keeping H2value as constant. Note the diameter of the

Orifice and area of the tank.

4. In this case, of constant head method the height h is kept constant and the time

taken for 10cm size in the collecting tank is found out.

5. Then vary the height and find the corresponding time. After taking 5 readings

switch of the motor.

RESULT:

1. Coefficient of discharge by varying head method =

2. Coefficient of discharge by constant head method =

TABULATION:

VARYING HEAD METHOD:

HEADTIME H1-H2


24/27

Cd = 2A(H1-H2)

S.No H1 cm H2 cm (T) S cm 2g aT

TABULATION:

CONSTANT HEAD METHOD:

S.No H1H=H1-H0Cm Cm

SYSTEM DETAILS:

Diameter of orifice (d)

Area of collecting tank (A)

Area of mouth piece (a)

Qthx10-4

M3/s

Time for

10cm rise

(s) t

=

=

=

Qact x 10-4

M3/s

Cd

Level of water at the centre of mouth piece (H0) =

Ex.No

Date

AIM:

:

:MULTISTAGE CENTRIFUGAL PUMP

[ PARALLEL AND SERIES CONNECTION]

To study the characteristics of two similar pumps connected in parallel and in

series and to compare the same with that obtained from the characteristic of one of the

two pumps by extrapolation.

APPARATUS REQUIRED:

1. Pump setup

2. Stop watch


25/27

3. Steel rule

DESCRIPTION:

A centrifugal pump which works on the principle of forced vertex flour consists

of an impeller rotating inside a casing. It converts the mechanical energy into pressureenergy by means of centrifugal force acting on the fluid.

The test rig consists of two similar pump of size 25mm x 25mm each and are

driven by 0.5. Ampere capacity are fitted in the delivery and section pipes to measure thehead.

An energy meter and a stop water are provided to measure the input to the motor

and a collecting tank to measure the actual discharge.

TEST ON SINGLE PUMP:

EXPERIMENTAL PROCEDURE:

1. Prime the pump if necessary

2. Close the regulating value totally and switch on the motor.

3. Adjust the gate value to get the required head.

4. Note down the following readings.(a) The pressure gauge reading (Kgf/cm2)(b) Time for Impulse resolution of the energy meter disc in sec (T)(c) The time for h m size in collecting tank in sec.(d) The vacuum pressure gauge reading (mm of Hg)

(e) Repeat the experiments for other. Take minimum 6 set of readings.

TEST SETUP FOR PARALLEL OPERATION:

To similar pumps are connected in such a way that it may be operated in parallel

by manipulating large quantity of water the pump are connected in parallel.


26/27

EXPERIMENTAL PROCEDURE:

1. Prime the pump if necessary.2. Close the regulating value fully and switch on the motor the pump are connected

in parallel.

3. Adjust the gate value to get the required head.4. Note down the following details.

(a) The pressure gauge reading (kgf/cm2)(b) The vacuum gauge reading (mm of Hg)(c) Time for Impulse revolution of the energy meter disc (T) in sec.(d) Time for h size in the collecting tank t in sec.

(e) Repeat the experiment for the other heads take minimum 6 set of reading.

TEST SETUP FOR SERIES OPERATION:

Two similar pumps are connected in such a way that they may be operated in

series by manipulating the values provided by developing a high head of water, the

pumps are connected in series.The following graph are plotted by taking Qact along x-axis and remaining co-

ordinates along y-axis for single pump.

(i) Qact vs output

(ii) Qact vs total head

(iii)Qact vs efficiency.

FOR SERIES CONNECTION:

Qact vs total head and also draw for single pump.

FOR PARALLEL CONNECTION:Qact vs total head for single and parallel connection.

RESULT:

PARALLEL CONDITION:

Maximum efficiency obtainedCorresponding discharge Q

Corresponding Input power

Corresponding Output powerCorresponding maximum head

SERIES CONDITION:

Maximum efficiency obtainedCorresponding discharge Q

Corresponding Input power

Corresponding Output powerCorresponding maximum head

==

=

==

=

=

=

==

SERIES

CONNECTIO

N:S

u

c

tio

n

He

ad

(Hs)

S.No

Va

cuum

gauge

Hs

reading

mm

(m)


27/27

SYSTEM DETAILS:

Delivery Head

(Hd)

Pressure gauge

Hd

reading kgfkm2Ng(m)

Total head

time

for hm riseH=Hs+Hd+x

Time for 10

impulse in

EMD

IMP

10cm

Acutal

discharge

Qact x 10-

3

m3/s

Output

frompump

(kw)

Input

to themotor

(kw)

=

I/P

10

Internal plan dimension of collecting

tank

Energy meter constant

Difference in level between pressure

gauge

and vacuum

gauge

Specific gravity of water

=

=

=

=

Hydraulic Engineering Lab Manual

Documents

Transcript of Hydraulic Engineering Lab Manual