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SRI SIVASUBRAMANIYA NADER COLLEGE OF ENGINEERING,

KALAVAKKAM- 603110.

FLUID MECHANICS & MECHINERY LAB MANUAL

I – CYCLE EXPERIMENTS

1. RECIPROCATING PUMP

2. CENTRIFUGAL PUMP

3. PIPE FRICTION APPARATUS

4. ORIFICE METER

5. VENTURIMETER

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1. RECIPROCATING PUMP

AIM:

To conduct a test on Reciprocating Pump and to design the parameters of the pump.

APPARATUS REQUIRED:

Stop Watch and Meter scale.

FORMULAE:

H= Hs + Hd + Hc

Q= LBY/ t1

IP= 3600 X n / Ec X t2 KW

OP= WQH / 1000KW

η =OP / IP x 100

H = Total head in m

Hs= Suction head in m

Hd = Delivery head in m

Hc = correction head in m

Q = Discharge in m 2/sec

L = Length of the collecting tank in m

B = Breath of the colleting tank in m

Y= Rise of water in collecting tank (0.1m)

t1 = Time taken for 10 cm rise in seconds

IP = Input Power in Kw.

N = Number of revolutions (Generally 5)

Ec = Energy meter constant (rev/Kwh)

t2= Time taken for 5 revolution in energy meter in seconds

OP= Output power in Kw.

W = Specific weight of water = 9.81x 103 N/m

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Model Calculation for Reciprocating Pump

1. Hs = 180 x 13.6/1000 = 2.448 m

2. Hd = 1 x104 x 9.81 /9810 = 10.00 m

3. Hc = 15 cm = 0.15 m

4. Total head H = Hs + Hd + Hc = 12.598 m

5. Discharge Q = LBY/t1 = 0.3x0.3x0.1 / 20 = 4.5 x 10-4

cu.m/sec.

6. Output power OP = WQH / 1000 = 9810x 4.5 x 10-4

x12.598 / 1000 = 0.0558 kw.

7. Input power IP = 3600 x n/Ec.t2 = (3600x5) / (600x72) = 0.4166 kw

8. Efficiency η = OP/IP x 100 = 0.0558/0.4166 x 100 = 13.35%.

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Procedure:

1. Note the system details,

(a) Details of the pump.

(b) Size of the collecting tank.

(c) Energy meter constant.

(d) Distance between pressure gauge tapings (Hc)

2. Keep the delivery valve fully opened.

3. Switch on the motor.

4. Observe the following.

(a) Suction pressure.

(b) Delivery pressure.

(c) Time taken for 10 cm rise in collecting tank t1in section.

. (d) Time taken for 5 revolutions of energy meter reading t2 in sections

5. Repeat the experiment for different settings of the delivery valve.

6. Observations are entered in a well-prepared tabular statement and computations are

made as explained under model calculation

7. Plot the graph between discharges, Q on. X axis Vs IP efficiency η, Total head on Y-axis.

RESULT :

A test was conduced on Reciprocating pump and characteristics curves were drawn

Maximum Efficiency= -----------------%

Corresponding Input= -----------------Kw.

Corresponding Total Head = -------------------m.

Corresponding Discharge =------------------m3/sec

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OBSERVATION TABLE FOR RECIPROCATING PUMP

Sl..No

Suction

Pressure

Delivery

Pressure

Time for

10cm.

Rise

Time For

5rev .of

Energy

Meter

Suction

Head

Delivery

Head

Total

Head

Discharge Input

Power

Output

Power Efficiency

Ps

Pd

t1 t2 Hs Hd H Q Ip Op η

mm. of Hg. kg/sq. cm. Sec. Sec. m m m cu .m/Sec. IP OP %

1

2

3

4

5

6

CORRECTION HEAD = 15 cm

ENERGY METER CONSTANT = 600 rev/kwh.

LENGTH OF COLLECTING TANK = 30cm.

BREADTH OF COLLECTING TANK = 30 cm

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2. CENTRIFUGAL PUMP

AIM:

To conduct a test on Centrifugal pump and to design the parameters of the pump.

APPARATUS REQUIRED:

Stopwatch and Meter scale

.

FORMULAE:

H = Hs + Hd +Hc

Q = LBY/t1

IP = 3600X n / (Ec X t2) KW

OP = WQH/1000 KW

η = OP/ IP X 100

H = Total head in m

Hs = Suction head in m

Hd = Delivery head in m

Hc = Correction head in m

Q = Discharge in m3/ sec.

L = Length of the collecting tank in m

B = Breadth of the collecting tank in m

Y = Rise of water in collecting tank ( 0. 1m)

t1 = Time taken for 10 cm rise in seconds

IP = Input power in kw

N = Number of revolutions (Generally5)

Ec = Energy meter constant (rev/ kwh)

t2 = Time taken for 5 revolutions in energy meter in seconds

OP = Out power in kw.

W = Specific weight of water = 9.8x103 N/m

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Model Calculation for Centrifugal Pump

1. Suction head ( Hs) = 300 x 13.6 / 1000 m = 4.08 m

2. Delivery pressure ( Pd) = 1.2 kg/sq.cm

3. Delivery head ( Hd) = (Pd x 104 x 9.81)/9810 m

= (1.2 x 104 x 9.81)/9810 = 12 m

4. Correction head (Hc) = 0.47 m

5. Total head (H) = Hs+Hd+Hc m

= 4.08+12+0.47 = 16.55m

6. Discharge Q = LBY/t1 cu.m /sec.

= (0.7x0.7x0.1)/16.38 cu.m/sec.

7. Output power (OP) = WQH / 1000 kw

= 9810x2.99x10x16.55/1000 = 0.4854 kw.

8. Input power (IP) = (3600xn)/Ecxt2 kw

= (3600x5)/600x20.65 = 1.453 kw

9. Efficiency η = OP/IP x100 kw

=(0.4854/1.453) x 100 = 33%

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PROCEDURE:

1. Note the system details

(a) Details of the pump. (HP and Speed)

(b) Size of the collecting tank.

(c) Energy meter constant.

(d) Distance between presser gauge and vacuum gauge tapping (HC)

2. Keep the delivery valve almost closed.

3. Switch on the motor.

4. For any desired opening note the following.

(a) Suction pressure. (Ps)

(b) Delivery pressure (Pd)

(c) Time taken for 10cm rise in collecting tank t1 in second

(d) Time taken for 5revealation of energy meter reading t2 in seconds

5. Repeat the experiment for differing settings of the delivery valve.

6. Observation s are entered in a well-prepared tabular statement and computations are made as

explained under model calculation.

7. After the observations are made, switch off the motor

8. Plot the graph between discharges, Q on X-axis Vs Ip, efficiency η Total head on Y-axis.

RESULT:

A test was conduced on Centrifugal pump characteristics curves were drawn

Maximum Efficiency =-----------------%

Corresponding input power =-----------------Kw

Corresponding Total Head = -----------------------m.

Corresponding Discharge ------------------------m3 / sec

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OBSERVATION TABLE FOR CENTRFUGALPUMP

CORRECTION HEAD = 48 cm

ENERGY METER CONSTANT =600 rev/kwh

LENGTH OF COLLECTING TANK = 70 cm

BREADTH OF COLLECTING TANK = 70 cm

Sl.No Suction

Pressure

Delivery

Pressure

Time

For10cm.

Rise

Time For

5rev of

Energy

Meter

Suction

Head

Delivery

Head

Total

Head Discharge

Output

power Efficiency

Ps Pd t1 t2 Hs Hd H Q OP OP

mm. of Hg Kg/sq.cm Sec. Sec m m m cu.m/Sec Kw Kw

1

2

3

4

5

6

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3. FLOW THROUGH PIPES

AIM:-

To determine Friction factor ‘f’ of the given pipe and also fine the Chezy’s constant ‘c”.

APPARATUS REQUIRED:-

1. Pipe provided with inlet, outlet and pressure tapings.

2. U- tube manometer.

3. Collecting tank

4. Stop watch.

5. Metre scale.

FORMULAE:

1. Loss of head due to friction

hf = 4flv2/2gD

Where, f- friction factor

l - length of pipe

v - velocity of flow in pipe m/s

D – diameter of pipe

hf = head loss in m. (h1-h2) x {(Sm/Sw) -1}

h1 - left limb reading of manometer

h2 - right limb reading of manometer

Sm – Sp. Gravity of mercury

Sw – Sp. Gravity of water

2. Actual Discharge

Qa = Ay/t m3/s

Where, A – area of collecting tank in m2

y – rise of water in collecting tank (10 cm)

t – time taken for 10 cm rise of water in sec.

3. Velocity of flow

v = c√mi

Where, v = Qa/a

Qa – Discharge

a – area of the pipe {(π/4) x d2}

c – chezy’s constant

m – hydraulic mean depth – A/D

i- hydraulic gradient – hf/L

v – velocity of flow in pipe.

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PROCEDURE:

1. The system details of flow through pipes are noted.

(a) the diameter of the pipe

(b) length of the pipe

(c) collecting tank dimensions

(d) manometer reading

2. The supply value is opened fully.

3. Simultaneously the inlet and outlet pipes are opened.

4. The water is let into the limbs of the manometer.

5. The air bubbles in the manometer are removed by opening the valve slowly.

6. The left and right limbs are opened noted.

7. Then the time taken for 10cm rise is noted.

8. The experiment is repeated for various discharges and observations are tabulated.

GRAPH:

Draw graph Qa along X- axis and hf along Y- axis for both diameter from which the friction

loss can be compared.

RESULT:

(i) d1 = 25 mm

Friction factor ‘f’ of the pipe = _________________

Chezy’s constant of the pipe = _________________

(ii) d2 = 15 mm

Friction factor ‘f’ of the pipe = _________________

Chezy’s constant of the pipe = _________________

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OBSERVATION TABLE FOR FLOW THROUGH PIPES

(i) d1 = 25 mm

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec Qa

m3/sec

V

m/s hf f c

h1 h2 h1- h2 t1 t2 t(s)

1

2

3

4

5

6

7

Average f = ----------------

Average c = ---------------

Diameter of the pipe d1 = 25 mm

Length of the pipe l = 200 cm

Collecting tank dimensions = 40 x 40 cm.

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OBSERVATION TABLE FOR FLOW THROUGH PIPES

(i) d2 = 15 mm

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec Qa

m3/sec

V

m/s hf f c

h1 h2 h1- h2 t1 t2 t(s)

1

2

3

4

5

6

7

Average f = ----------------

Average c = ---------------

Diameter of the pipe d2 = 15 mm

Length of the pipe l = 200 cm

Collecting tank dimensions = 40 x 40 cm.

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4. FLOW THROUGH ORIFICE METER

AIM:-

To determine the coefficient of discharge of the given Orifice meter.

APPARATUS REQUIRED:-

1. Orifice meter.

2. U- tube manometer.

3. Collecting tank

4. Stop watch.

5. Metre scale.

Principle:

Coefficient of discharge is defined as the ratio of actual discharge to theoretical discharge.

FORMULAE:

1. Actual Discharge

Qa = Ay/t m3/s

Where, A – area of collecting tank in m2

y – rise of water in collecting tank (10 cm)

t – time taken for 10 cm rise of water in sec.

2. Theoritical Discharge

Qth = {(a1 x a2) √ (2gh)} / {√ (a12 – a2

2)} m

3/s

Where, in 25 mm pipe - a1 – area of orifice inlet (d1 = 25 mm),

a2 - area of orifice inlet (d2 = 15 mm)

in 20 mm pipe - a1 – area of orifice inlet (d1 = 20 mm),

a2 - area of orifice inlet (d2 = 12 mm)

h = (h1-h2) x {(Sm/Sw) -1} m

h1 - left limb reading of manometer

h2 - right limb reading of manometer

Sm – Sp. Gravity of mercury

Sw – Sp. Gravity of water

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PROCEDURE:

1. Open the outlet valve completely and switch on the motor.

2. Now open the inlet valve of pipe and orifice meter inlet and outlet valve.

3. With particular opening of the inlet valve note the readings on the two limbs of the

manometer.

4. Calculate the actual discharge using the collecting tank and stopwatch wand the

theoretical discharge.

5. Now change the opening of the inlet and note the readings of the manometer. Take six

such readings of both the pipes.

6. Calculate the coefficient of discharge.

Graph:

Plot a graph between Qa & Qth

RESULT:

The coefficient of discharge for Orifice meter in 25 mm pipe is ________________

The coefficient of discharge for Orifice meter in 15 mm pipe is _________________

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OBSERVATION TABLE FOR ORIFICE METER

(i) D = 25 mm Pipe

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec

Qa

m3/sec

Qa

m3/sec

Cd

h1 h2 h1- h2 t1 t2 t t(s)

1

2

3

4

5

6

7

Average Cd: _______

Collecting tank dimensions = 40 x 40 cm.

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OBSERVATION TABLE FOR ORIFICE METER

(i) D = 20 mm Pipe

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec

Qa

m3/sec

Qa

m3/sec

Cd

h1 h2 h1- h2 t1 t2 t t(s)

1

2

3

4

5

6

7

Average Cd: _______

Collecting tank dimensions = 40 x 40 cm.

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5. FLOW THROUGH VENTURI METER

AIM:-

To determine the coefficient of discharge of the given Venturi meter.

APPARATUS REQUIRED:-

1. Venturi meter.

2. U- tube manometer.

3. Collecting tank

4. Stop watch.

5. Metre scale.

Principle:

Coefficient of discharge is defined as the ratio of actual discharge to theoretical discharge.

FORMULAE:

1. Actual Discharge

Qa = Ay/t m3/s

Where, A – area of collecting tank in m2

y – rise of water in collecting tank (10 cm)

t – time taken for 10 cm rise of water in sec.

2. Theoritical Discharge

Qth = {(a1 x a2) √ (2gh)} / {√ (a12 – a2

2)} m

3/s

Where, in 25 mm pipe - a1 – area of orifice inlet (d1 = 25 mm),

a2 - area of orifice inlet (d2 = 15 mm)

in 20 mm pipe - a1 – area of orifice inlet (d1 = 20 mm),

a2 - area of orifice inlet (d2 = 12 mm)

h = (h1-h2) x {(Sm/Sw) -1} m

h1 - left limb reading of manometer

h2 - right limb reading of manometer

Sm – Sp. Gravity of mercury

Sw – Sp. Gravity of water

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PROCEDURE:

1. Open the outlet valve completely and switch on the motor.

2. Now open the inlet valve of pipe and orifice meter inlet and outlet valve.

3. With particular opening of the inlet valve note the readings on the two limbs of the

manometer.

4. Calculate the actual discharge using the collecting tank and stopwatch wand the

theoretical discharge.

5. Now change the opening of the inlet and note the readings of the manometer. Take six

such readings of both the pipes.

6. Calculate the coefficient of discharge.

Graph:

Plot a graph between Qa & Qth

RESULT:

The coefficient of discharge for Venturi meter in 25 mm pipe is _______________

The coefficient of discharge for Venturi meter in 15 mm pipe is _______________

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OBSERVATION TABLE FOR VENTURI METER

(i) D = 25 mm Pipe

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec

Qa

m3/sec

Qa

m3/sec

Cd

h1 h2 h1- h2 t1 t2 t t(s)

1

2

3

4

5

6

7

Average Cd: _______

Collecting tank dimensions = 40 x 40 cm.

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OBSERVATION TABLE FOR VENTURI METER

(i) D = 20 mm Pipe

S. No Manometer reading in m

Time taken for 10 cm rise of water

in sec

Qa

m3/sec

Qa

m3/sec

Cd

h1 h2 h1- h2 t1 t2 t t(s)

1

2

3

4

5

6

7

Average Cd: _______

Collecting tank dimensions = 40 x 40 cm

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