Academic Year: 2014-15
Question Bank for Skill Test of
Fluid Mechanics & Machineries
(For Experiment No. 1,2,3,4,5,6,7,8,9)
1
Academic Year: 2014-15
1. To measure fluid pressure by using manometer & pressure gauges and discharge of
water by using measuring tank and stop watch.
1. Write down title of the experiment.
2. Note down the apparatus needed
3. Draw the diagram of differential manometer and constructional diagram of Bourdon tube
pressure gauge.
4. Note down the stepwise procedure.
5. Observations:

Pressure Gauge readings:
(i) 0.5 kg/cm2 =……….N/m2
(ii) 0.7 kg/cm2 =……….N/m2
(iii) 1.0 kg/cm2 =……….N/m2
 S1- Specific gravity of liquid flowing through pipe (water) = 1
 S2- Specific gravity of manometer fluid(mercury) = 13.6
 Area of tank A = 0.175 m2
6. Prepare observation table and note down readings.
Sr. Height
Height of Difference Differential
Differential
No. of Hg in Hg in
X=(h1head in
head in
left limb right limb h2)/100
meters of
N/m2
(h1)
(h2)
water
m
H= X(S2-S1)/
(P)
cm
cm
S1
1
26.4
20.8
2
25.9
21.3
3
25.3
21.9
7. Sample Calculation.
8. Result
a) For First Flow rate
1. Bourdon tube Pressure Gauge =
2. Discharge =
=
b) For Second Flow rate
1. Bourdon tube Pressure Gauge =
2. Discharge =
=
c) For Third Flow rate
1. Bourdon tube Pressure Gauge =
2. Discharge =
=
Rise in
Water
level
in Tank
Hw
meter(m)
0.05
0.05
0.05
Time to
collect the
water in
measuring
tank
t
second
15
17
20
N/m2
m3/sec
N/m2
m3/sec
N/m2
m3/sec
2
Academic Year: 2014-15
2. Calibration of Bourdon Tube Pressure Gauge with the help of Dead Weight Pressure
Gauge.
1. Write down title of the experiment.
2. Note down the apparatus needed
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Observations :(i) Diameter of piston (d) = 1.129 cm
(Area of piston = 1 cm2 )
6. Prepare observation table and note down readings.
Sr
.
N
o
1
2
3
4
5
6
7
8
9
10
Dead
Weigh
t
Kg
1
2
3
4
5
6
7
8
9
10
Dead weight
generated
pressure
(True value)
Pc
Test gauge
readings Pgi
(Increasing)
Kg/cm2
1
2
3
4
5
6
7
8
9
10
Kg/cm2
0.8
1.5
2.5
3.5
4.9
7.0
6.5
9.0
9.5
10.0
Test gauge
readings Pgd
(Decreasing
)
Average
Pg
Kg/cm2
0.5
1.0
2.0
2.9
3.4
4.5
5.5
7.0
8.0
9.0
Kg/cm2
Absolute
error
P c - Pg
Kg/cm2
%
Error
Pc − Pg
Pg
%
7. Sample Calculation.
8. Draw the graph of Pc (Kg/cm2) Vs Pg (Kg/cm2)
9. Result
1. Maximum error is _____________ for dead weight _______ kg
2. Average % error is ______________
3
Academic Year: 2014-15
3. To study & verify Bernoulli’s Theorem
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Observations: (Note: For this experiment all measurements are in cm)
 Area of measuring tank A = 1500 cm2
 Rise of water level in tank in 20 sec. r = 6 cm
 Time t = 20 sec
 V2/2g – Velocity head
 P/W – Pressure head
 Z – Potential head
 g = 981 cm/sce2
6. Prepare observation table and note down readings.
Sr.
No.
1
2
3
4
5
6
7
8
9
10
11
Tube
No.
1
2
3
4
5
6
7
8
9
10
11
Crosssectional
area
A
cm2
25 X 2.5
22 X 2.5
19 X 2.5
16 X 2.5
13 X 2.5
15 X 2.5
17 X 2.5
19 X 2.5
21 X 2.5
23 X 2.5
25 X 2.5
Discharge
Qd
(A X r)/t
Velocity
V
Qd/a
Velocity
head
V2/2g
Pressure
head
p/w
cm3/sec
cm/sec
cm
cm
54
37
34
32
21
24
23
24
25
27
29
Total head =
Velocity
head +
Pressure head
Cm
7. Sample Calculation.
8. Result
:
The total maximum head =
cm of water.
The total minimum head =
cm of water.
Loss of head is =
cm of water
9. Draw the graph of (i) p/w Vs No. of tubes
(ii) V2/2g Vs No. of tubes
(iii) (P/W)+(V2/2g) Vs No. of tubes
4
Academic Year: 2014-15
4. To determine coefficient of discharge for a given Venturimeter.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of venturimeter.
3. Note down the stepwise procedure.
4. Observations :
(i)
Diameter of inlet pipe d1 = 2.6 cm =
m
𝜋
2
2
(ii)
Area of inlet pipe a1 = 4 d1 =
m
(iii) Diameter of throat d2 = 1.4 cm =
m
𝜋
2
2
(iv)
Area of inlet pipe a2 = 4 d2 =
m
(v)
Cross section area of measuring tank A = 50 x 35 cm2
(vii) S1- Specific gravity of liquid flowing through pipe (water) = 1
(viii) S2- Specific gravity of manometer fluid (mercury) = 13.6
5. Prepare observation table and note down readings.
Sr. Rise of water
No. Level of
measuring
Tank
Deflection of
the mercury columns
of the manometer.
Hthroat Hpipe Hhg =
Converted water
column
height (m)
H = HHg X 12.6
(𝐻𝑝𝑖𝑝𝑒 – 𝐻𝑡ℎ𝑟𝑜𝑎𝑡 )
Time to
collect the
water in
measuring
tank
100
1
2
3
4
cm
5
5
5
5
M
cm
20.8
21.3
21.9
22.6
cm
26.4
25.9
25.3
24.6
M
m
Sec
15
17
20
26
6. Sample Calculation.
7. Result
Average coefficient of discharge is _______
5
Academic Year: 2014-15
5.To determine coefficient of Discharge, Coefficient of contraction and Coefficient of
Velocity of sharp edged circular orifice.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Prepare observation table and note down readings.
1. Shape of orifice: Circular
2. Diameter of orifice (d)= 0.16 m
3. Area of cross section of Orifice (a) = m2
4. Area of cross section of measuring tank (A) = 0.175 m2
5. Initial reading on horizontal scale (X) = 0 m
6. Initial reading on vertical scale (Y) = 0.092 m
7. Initial reading on piezometric scale (h1) = 0 m
Reading for calculating Cd
Sr. Reading on h =
Rise in
Time
Actual
Theoretical Cd =
𝑄𝑎𝑐𝑡
No. piezometric h2-h1
level of
(T)
Discharge Discharge
scale of
eater in
Qact =
Qth =
𝑄𝑡ℎ
𝐴𝑋𝐻
intake tank
measuring
a√2𝑔ℎ
(h2)
tank (H)
𝑇
m
m
m
sec
m3/sec
m3/sec
1
0.21
0.05
26
2
0.19
0.05
28
3
0.17
0.05
29
4
0.16
0.05
30
5
0.15
0.05
31
Reading for calculating Cv & Cc
Sr.
X
Y
No.
H
Cv
=
Cc
𝑋
√4.𝑌.ℎ
1
2
3
4
5
0.15
0.13
0.10
0.10
0.09
=
𝐶𝑑
Average
Cv
Average
Cd
Average
Cc
𝐶𝑉
0.02
0.05
0.04
0.04
0.03
6. Sample Calculations
7. Result
:
For Circular Orifice
1. Coefficient of Discharge (Cd) =
2. Coefficient of Velocity (Cv) =
3. Coefficient of Contraction (Cc) =
6
Academic Year: 2014-15
6.To determine darcy’s friction factor ‘f’ in pipe for four different discharge.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Prepare observation table and note down readings.
1. Material of pipe _______________________
2. Area of Measuring tank A= 50 X 30 cm2 =
m2
3. Distance between tappings =
4. Specific gravity of fluid in pipes S1 = 1 (for water)
5. Specific gravity of fluid in manometer S2 = 13.6 (for mercury)
Observation table: Readings for calculation of Darcy’s friction factor
Sr. Diameter
Manometer Readings
hf =
Rise in
Time for
Q=
No. of
12.6 x height of collection A. Hm
x1
x2
x=
pipe
cm of water in
of water
x1 –
t
water measuring in
x2
tank Hm
measuring
tank
t
mm
cm
cm
cm
cm
M
sec
m3/sec
1
25.2
48.5
10.5
0.23
20
2
25.2
45.0
9.6
0.17
20
3
25.2
41.4
8.7
0.11
20
4
25.2
40.5
5.6
0.08
20
Darcy’s
friction
factor
f
6. Sample Calculations
7. Result
:
For pipe ______________________ average darcy’s friction factor is ____________
7
Academic Year: 2014-15
7. To determine minor losses for flow through pipes.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Observations :
1. Measuring tank dimensions, length l = 50 m, breadth, b= 40 m,
2. Time interval for measuring riser in water level, t = 20 sec
3. For sudden enlargement :
Dia. of pipe at entry (d1) = 15.99 mm =
m
Dia. of pipe at outlet (d2) = 25.91 mm=
m
4. For sudden contraction
Dia. of pipe at entry (d1) = 25.91 mm =
m
Dia. of pipe at outlet (d2) = 15.99 mm=
m
0
5. Angle of bend 90 , Dia. of pipe at entry (d5) = 12.6 mm=
6. Angle of elbow, Dia. of pipe at entry (d6) = 12.6 mm=
m
m
4. Prepare observation table and note down readings.
Sr.
No.
Nature of
pipe fittings
Inlet &Exit Manometer
Pressure
Diameters readings
difference hg
of pipe
H1(cm) H2(cm) = 𝐻2−𝐻1 ‘m’
100
(mm)
of Hg
(mercury)
1
Sudden
Enlargement
Sudden
Contraction
Bend
Elbow
d1=
d2=
d3=
d4=
d5=
d6=
2
3
4
Actual head
lost in meters
of water
column (m)
H= 12.6 hg
46.1
10.1
Rise of
water
level in
tank
(Hw)
metre
0.26
45.1
15.6
0.21
12.5
11.5
2.3
5.5
0.15
0.17
5. Sample calculation.
6. Result
:
1. For sudden enlargement
a. Actual loss of head =
b. Theoretical loss of head=
2. For sudden contraction
a. Actual loss of head =
b. Theoretical loss of head=
3. Constant for bend K=
4. Constant for elbow K=
m of water
m of water
m of water
m of water
8
Academic Year: 2014-15
8. To determine overall efficiency of a Pelton wheel turbine by conducting a trial test on it.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Observations :1. Diameter of brake drum = 0.276 m
a1 .a2
2. Venturimeter constant = Cd
2g
2
2 √
√a1 −a2
(m3) = 0.02498 m =
6. Prepare observation table and note down readings.
Sr.
No.
Pressure
Gauge P
kg/cm2
1
2
3
4
5
5.5
5.4
5.2
4.8
4.5
Manometer reading
Load applied on turbine
Right
Left
Pressure head
Pressure
Pressure
Dead
Spring
h=
Gauge
Gauge
weight
Load
(ℎ1 − ℎ2)𝑋 12.6
of
of pipe
W1
S2
throat
1000
(h1)
(h2)
mm of
mm of
m of water
kg
kg
Hg
Hg
55
50
0.005
6.4
1.5
62
35
0.027
15.2
1.5
102
40
0.062
23.7
1.5
280
140
0.14
32.5
2
292
102
0.19
36.5
2
Speed of
turbine
N
rpm
700
700
700
700
700
7. Sample Calculation.
8. Result
:
The average overall efficiency of Pelton wheel is
%
9. Draw the graph of Efficiency Vs Power.
9
Academic Year: 2014-15
9.To determine overall efficiency of a Centrifugal pump by conducting a trial test on it.
1. Write down title of the experiment.
2. Note down the apparatus needed.
3. Draw diagram of set up needed to conduct experiment
4. Note down the stepwise procedure.
5. Observations :
1. Cross sectional area of rectangular measuring tank
A = L X B = 0.5 X 0.35 m2
=
m2
2. Efficiency of electric (Power factor Φ) motor used = 0.85
3. Specific weight of water = 9810 N/m3
4. Level difference between suction and delivery pressure gauge X = 0.21 m
6. Prepare observation table and note down readings.
Sr. Suction Pressure
Delivery Pressure Rise in
No. Pressure Head at
Pressure Head
Water
(p1)
inlet
(p2)
at
level
H1 =
Outlet
in Tank
𝑝1 ∗ 13.6
H2 =
H
1000
p2 X 10
mm Hg
m
kg/cm2
m
cm
1
190
0.25
5
2
170
0.3
5
3
150
0.35
5
4
140
0.4
5
5
100
0.45
5
Time of
Current Voltage
water
Collection in
Tank T
Seconds
9.38
10.40
11.66
13.01
15.56
Amp
0.74
0.71
0.68
0.67
0.65
Volt
168
167
167
166
166
7. Sample Calculations.
8. Result
The average overall efficiency of centrifugal pump is
%
9. Draw the graph of Efficiency Vs Power.
10
Academic Year: 2014-15
Important Formulae for All Experiments
11
Academic Year: 2014-15
Experiment No. 1
To measure fluid pressure by using manometer & pressure gauges and discharge of water
by using measuring tank and stop watch.
1) Conversion of pressure 1kg/cm2 = 98066.5 N/m2
2) Difference in head in metre of mercury X=(h1-h2)/100
3) Differential head in meters of water H= X(S2-S1)/ S1
where S1- Specific gravity of liquid flowing through pipe (water) = 1
4) S2- Specific gravity of manometer fluid(mercury) = 13.6
5) Pressure intensity p = w. H (N/m2)
where Specific weight w = 9810 N/m3
6) Discharge Q =
A.Hw
t
(m3/sec)
where
Area of tank = A in m2,
Rise of water level = Hw in metres,
Time to collect the water in measuring tank = t in seconds
12
Academic Year: 2014-15
Experiment No. 2
Calibration of Bourdon Tube Pressure Gauge with the help of Dead Weight Pressure
Gauge.
Area of piston a =
𝛱
4
d2 (cm2)
Where d = diameter of piston in cm
Dead weight generated pressure = Dead weight X a (kg/cm2)
13
Academic Year: 2014-15
Experiment No. 3
To study & verify Bernoulli’s Theorem.
1. Actual discharge Qd =
A. r
t
(cm3/sec)
where
Area of tank A in cm2
Rise of water level r in cm
Time to collect the water in measuring tank t in seconds
2. Velocity V =
Qd
a
Where
A = area of corresponding tube section
V2
3. Velocity head = 2.g
where
g = 981 cm/sec2
p
4. Pressure head = w cm
(Actual measured from scale)
5. Total head = Velocity head + Pressure head
14
Academic Year: 2014-15
Experiment No. 4
To determine coefficient of discharge for a given Venturimeter.
1. Volume of water collected = Area of tank X Rise in height of water
2. Actual Discharge Qact
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟 𝑐𝑜𝑙𝑙𝑒𝑐𝑡𝑒𝑑
Qact =𝑇𝑖𝑚𝑒 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑓𝑜𝑟 𝑐𝑜𝑙𝑙𝑒𝑐𝑡𝑖𝑜𝑛 (m3/sec)
3. Calculation of theoretical discharge Qth.
Qth =
𝑎1 𝑎2
√𝑎12 − 𝑎22
√2𝑔𝐻 (m3/sec)
Where
Diameter of inlet pipe of venturimeter d1 in metres
Diameter of throat of venturimeter d2 in metres
𝜋
a1 = 4 d12
𝜋
a2 = 4 d22
Hhg = (Hpipe – Hthroat) / 100 (metre)
Differential head in metre of water H = HHg X 12.6
4. Calculation of coefficient of discharge Cd
Actual Discharge
Cd = Theoretical Discharge
15
Academic Year: 2014-15
Experiment No. 5
To determine coefficient of Discharge, Coefficient of contraction and Coefficient of Velocity
of sharp edged circular orifice.
1. Area of orifice(a)
𝜋
a = 4 d2
2. Actual Discharge Qact
𝐴 .𝐻
Qact =
𝑇
(m3/sec)
3. Theoretical Discharge (Qth)
Qth = a √2 𝑔 ℎ
4. Coefficient of discharge Cd
Cd =
Qact
Qth
5. Coefficient of velocity Cv.
Cv =
𝑋
√4.𝑌.ℎ
6. Coefficient of contraction Cc
C
Cc = Cd
v
16
Academic Year: 2014-15
Experiment No. 6
To determine darcy’s friction factor ‘f’ in pipe for four different discharge
1. Difference in mercury in cm x = x1 – x2
where
Mercury reading on right limb x1 in cm
Mercury reading on right limb x2 in cm
2. Actual loss of head in metre of water hf = x X (
s2−s1
s1
) (m)
3. Actual Discharge Q
Q=
Area of tank (A) in m2 X rise in liquid level(Hm ) in m
time taken (t)in sconds
Q=
4. hf =
A.Hm
t
(m3/sec)
f l Q2
3 d5
where
hf = Actual head loss in metre of water
f = Darcy’s friction factor
l = length of pipe
Q= Actual discharge im m3/sec
d = diameter of pipe in metre
So Darcy’s friction factor f =
3hf d5
l Q2
17
Academic Year: 2014-15
Experiment No. 7
To determine minor losses for flow through pipes.
1. Discharge of water Q = Quantity of water collection / time taken in second
Q=
l X b X Hw
(m3/sec)
t
where
l = length of measuring tank in metre
b= breadth of measuring tank metre
Hw = Rise of water level in tank in metre
t = interval for measuring riser in water level
2. Case 1: Loss of head due to sudden enlargement
1. Velocity of water at entry V1 = Q/A1
Where
Q = discharge in m3/sec
A1 = area of pipe at entry =
𝛱
4
d12
d1= diameter at inlet in metre
2. Velocity of water at outlet V2 = Q/A2
Where
Q = discharge in m3/sec
A2 = area of pipe at exit =
𝛱
4
d22
d2= diameter at outlet in metre
3. Theoretical loss of head due to sudden enlargement, He
He =
(𝑉1 −𝑉2 )2
2𝑔
m of water
3. Case 2: Loss of head due to sudden contraction
1. Velocity of water at entry V3 = Q/A3
Where
Q = discharge in m3/sec
A3 = area of pipe at entry =
𝛱
4
d32
d3= diameter at inlet in metre
2. Velocity of water at outlet V2 = Q/A4
Where
Q = discharge in m3/sec
A4 = area of pipe at exit =
𝛱
4
d42
d4= diameter at outlet in metre
18
Academic Year: 2014-15
3. Theoretical loss of head due to sudden contraction, Hc
V2
Hc =0.5 2g4 m of water
4. Case 3: Loss of head at bend
1. Actual loss of head for given bend =
m of water (from observation table)
2. Velocity of water flowing through bend V5 = Q/A5
Where
Q = discharge in m3/sec
A5 = area of pipe at entry of enlargement =
𝛱
4
d52
d5= diameter at bend in metre
3. Theoretical loss of head at bend, Hb
V2
Hb =K 2g4 m of water
4. Equating Actual loss of head = Theoretical loss of head
=
Constant for bend K =
5. Case 4: Loss of head at elbow
1. Actual loss of head for given elbow =
m of water (from observation
table)
2. Velocity of water flowing through elbow V6 = Q/A5
Where
Q = discharge in m3/sec
A6 = area of pipe at entry of enlargement =
𝛱
4
d62
d6= diameter at elbow in metre
3. Theoretical loss of head at elbow, Hb
V2
Heb =K 2g4 m of water
4. Equating Actual loss of head = Theoretical loss of head
=
Constant for elbow K =
19
Academic Year: 2014-15
Experiment No.8
Determine Overall Efficiency of Pelton wheel:1. Overall Efficiency = Output power/Input power X 100.
2. Output Power =
𝟐𝜫𝐍𝐓
𝟔𝟎
(watt)
Where
RPM N = RPM measured by Tachometer
𝐷
Torque T = (W1-S2) X 9.81 X 2
Weight W1 in kg
Spring Weight S2 in kg
Effective diameter D = 0.276 m
3. Input Power = w X Q X H (watt)
Where,
Specific Weight of Water w= 9810 (N/m3)
a1 .a2
Discharge Q= Cd
√2 g h (m3)
2
2
√a1 −a2
Venturimeter Constant = Cd
(ℎ1− ℎ2)𝑋 12.6
a1 .a2
√a1 2 −a2 2
√2 g = 0.02498 m
h=
(m of water)
1000
where
h1 is Manometer reading connected to pipe of venturimeter in mm
h2 is Manometer reading connected to throat of venturimeter in mm
Nozzle Pressure Head H = 10 . p (m)
where p = Nozzle pressure in kg/cm2
20
Academic Year: 2014-15
Experiment No.9
Determine Overall Efficiency of Centrifugal Pump:1. Overall Efficiency = Output power/Input power X 100.
2. Output Power = w X Q X Hm (watt)
Where,
Specific Weight of Water w= 9810 N/m3
Discharge Q= Volume/ Time=( A X H ) / T m3/sec.
Tank Area A = L X B = 0.5 X 0.35 = m2
Rise in water level - H is in metre in time T sec.
Total Manometric Head Hm = Suction head(Hs) + Delivery head(Hd) + Pressure Level
difference (X)
Hs= (P1 X 13.6)/1000 (m)
Suction Pressure P1 is in mm Hg
Hd= P2 X 10 (m)
X = 0.21 m
Delivery Pressure P2 is in kg/cm2
3. Input Power = Current X Voltage X Power factor (Watt).
Power factor = 0.85
21