UNIVERSITY OF ENGINEERING AND TECHNOLOGY, PESHAWAR
DEPARTMENT OF CIVIL ENGINEERING
FINAL LAB REPORT
Fluid Mechanics-II (LAB.)
CE-212L
Name
Osama Wali
Class No.
165
Registration No.
20pwCIV5433
Section
“P”
Date of submission
February 2023
Submit to
Engr. Tabinda Masood
FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
It is intended that this report provides with a clear and thorough presentation of the whole course
of Fluid Mechanics-II (LAB.) we studied in the class. It covers all the relevant information
related to the lectures in detail with the help of illustrations. The relevance of knowing the topics
matter is reflected by the real-world applications and for this purpose photos are also added.
These photos generally are used to explain how the relevant principles apply to real-world
situations.
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Table of Contents
Experiment No. 01 ........................................................................................................................................ 7
“To demonstrate different parts and the working principle of Hydraulic Bench” .................................... 7
1.1.
Theoretical background: ........................................................................................................... 7
1.2. APPARATUS ................................................................................................................................ 7
1.3. Description of Different Parts of Hydraulic Bench: ...................................................................... 7
1.4. Procedure: ...................................................................................................................................... 9
1.5. Purpose:.......................................................................................................................................... 9
1.6. Applications of Hydraulic Bench:.................................................................................................. 9
1.7. Observations and Calculations: ...................................................................................................... 9
Experiment No. 02 ...................................................................................................................................... 11
“To Determine the Discharge and Coefficient of Discharge over Rectangular Notch” ......................... 11
2.1. Apparatus: .................................................................................................................................... 11
2.2. Theoretical background: .............................................................................................................. 11
2.3. Observation and Calculation ........................................................................................................ 13
Experiment No. 03 ...................................................................................................................................... 14
“Determine the Discharge and Coefficient of Discharge over Triangular Notch” ................................. 14
3.1. Triangular Notch .......................................................................................................................... 14
3.2. Observations and Calculations ..................................................................................................... 15
Experiment No. 04 ...................................................................................................................................... 16
“Investigation of different types of flows using Osborne Reynold’s apparatus by visual observation” . 16
4.1. Objective: ..................................................................................................................................... 16
4.2. Apparatus ..................................................................................................................................... 16
4.3. Types of Flow .............................................................................................................................. 17
4.5. Observations and Calculations: .................................................................................................... 18
Experiment No. 05 ...................................................................................................................................... 19
“Investigation of different types of flow by using Osborne Reynold’s Apparatus by (Reynolds number
formula)” ................................................................................................................................................. 19
5.1. Apparatus: .................................................................................................................................... 19
5.2. Procedure: .................................................................................................................................... 19
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5.3. Observations and Calculations: .................................................................................................... 19
Experiment No. 06 ...................................................................................................................................... 21
“To Determine Theoretical and Actual Center of Pressure on Partially Submerged Body” ............... 21
6.1. Objective ...................................................................................................................................... 21
6.2. Apparatus ..................................................................................................................................... 21
6.3. Hydrostatic Force Theory ............................................................................................................ 21
6.4. Centre of Pressure ........................................................................................................................ 21
6.5. Hydrostatic Centre of Pressure .................................................................................................... 23
6.6. Actual Centre of Pressure ............................................................................................................ 23
6.7. Procedure: .................................................................................................................................... 23
6.8. Precautions ................................................................................................................................... 24
6.9. Conclusion ................................................................................................................................... 24
6.10. Observations and Calculations: .................................................................................................. 24
Experiment No. 07 ...................................................................................................................................... 25
“To determine the hydraulic coefficients (Cv, Cc and Cd) for small circular orifice provided at the side
of the tank”.............................................................................................................................................. 25
7.1. Theoretical background................................................................................................................ 25
7.2. Objective: ..................................................................................................................................... 26
7.3. Apparatus and parts of the apparatus: .......................................................................................... 26
7.4. Procedure: .................................................................................................................................... 26
7.4. Conclusion: .................................................................................................................................. 27
7.5. Observations and Calculations: .................................................................................................... 28
Experiment No. 8 ........................................................................................................................................ 30
“To determine the hydraulic coefficients (Cv , Cc and Cd) for a small circular orifice provided at the
bottem of the tank”.................................................................................................................................. 30
8.1. Theoretical background: .............................................................................................................. 30
8.2. Objective: ..................................................................................................................................... 30
8.3. Apparatus: .................................................................................................................................... 30
8.4. Procedure: .................................................................................................................................... 30
8.5. Observations and Calculations: .................................................................................................... 31
Experiment No. 9 ........................................................................................................................................ 33
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“To investigate the validity of Bernoulli’s theorem as applied to the flow of water by Bernoulli’s
theorem demonstration” .......................................................................................................................... 33
9.1. Theoretical background: .............................................................................................................. 33
9.2. Apparatus: .................................................................................................................................... 33
9.3. Different parts of the Bernoulli’s apparatus: ................................................................................ 33
9.4. Procedure: .................................................................................................................................... 34
Experiment No. 10 ...................................................................................................................................... 35
“To determine the relationship between head loss due to friction and velocity of the flow of water
through smooth bore pipe”...................................................................................................................... 35
10.1. Objective: ................................................................................................................................... 35
10.2. Theoretical background.............................................................................................................. 35
10.3. Apparatus: .................................................................................................................................. 35
10.4. Parts of the fluid friction apparatus: ........................................................................................... 35
10.5. Procedure: .................................................................................................................................. 37
10.6. Observation and Calculations: ................................................................................................... 37
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Experiment No. 01
“To demonstrate different parts and the working principle of
Hydraulic Bench”
1.1. Theoretical background:
Hydraulic Bench: A Hydraulic Bench is a self-contained water supply device that allows
recirculating of water from a Sump Tank into different hydraulic devices.
Centrifugal pump: A centrifugal Pump moves water from the Sump Tank through a hose into
a Water Inlet at the top of the bench.
1.2. APPARATUS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Sight Tube and Scale
Flow Control Valve
Motor On\Off Button
Centrifugal Pump
Dump Valve and Dump Valve Handle
Drain Valve
Sump Tank
Pump and Motor
Quick Release Connector
Side Wall Slots
Inlet Stilling Baffle Valve
Open Channel
Weir Carrier
Tank Stilling Baffle
Volume Measuring Tank
Over flow
1.3. Description of Different Parts of Hydraulic Bench:
Sight tube and Scale:
A sight tube and scale is connected to tapping in the base of the volumetric tank and give an
instantaneous indication of water flow.
Flow Control Valve:
It is used to regulate the flow in the pipe i.e. to increase or decrease the inflow of water in hydraulic
bench. When it is rotated clockwise it reduces the water flow and when it is moved
counterclockwise it increase the water flow.
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Motor On\Off Button:
This button is used to start or close the motor.
Centrifugal Pump:
It draws water from sump tank and supplies it for performing experiment.
Dump Valve and dump Valve Handle:
Dump valve is in the base of the volumetric tank opening the dump valve with dump valve handle
allows the entrained water to return to the sump tank to recycling and closing the dump valve
gathers the water in the volumetric tank.
Drain Valve:
Drain valve is used for discharging of water form sump tank.
Sump Tank:
The fluid used in hydraulic bench is stored in sump tank located at the bottom of hydraulic bench.
The water from the sump tank is supplied through pump. Sump tank has the capacity of 160 liters.
Quick Release Connector:
The connector allows flow for rapid substitution of accessories. Special purpose terminations may
be connected to the pump supply by screwing connector. No hand tools are required for doing so.
Side Wall Slots\Channel:
Side channels are provided to support the accessory on test.
Inlet Stilling Baffle Valve:
Inlet stilling baffle valve is used to supply water in the open channel.
Open Channel:
It is used in number of experiments. It provides passage for water for different
experiments.
Weir Carrier:
Two types of weirs are used frequently
•
•
Rectangular weir
Triangular weir
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Tank Stilling Baffle:
Volumetric measuring tank incorporates a stilling baffle inclined to reduce turbulence.
Volumetric Tank:
Water discharging form the accessory (channels) on test is collected in a volumetric measuring
tank. This tank is stepped to accommodate low or high flow rates.
Overflow:
An over flow adjacent to the sump returns the water to the sump tank in the event of incorrect use
of water.
1.4. Procedure:
a) To start with, make sure the Pump is off.
b) Set up the device to be tested, either a close-conduit device or water supply for open
channel flow, attached to the Water Inlet. Make sure all the connections are secured.
c) Ensure that the Supply Valve is closed, and that the Dump Valve is open. Switch the Pump
on.
d) Once the Pump is on, slowly open the Supply Valve to allow water to circulate through the
Bench.
e) Close the dump valve and gather some water in the volumetric tank.
f) Now measure the volume gathered through the sight tube and scale and note the time
required to fill the desirable volume of water on the stopwatch.
g) Open the dump valve to return water to sump tank.
h) Then again close he dump valve to take readings and repeat the procedure to take different
readings.
1.5. Purpose:
To find the discharge of water.
1.6. Applications of Hydraulic Bench:
•
•
•
•
•
•
Discharge of water "Q"
Co-efficient of discharge "Cd"
Co-efficient of velocity "Cv"
Co-efficient of contraction "C"
To study the characteristics flow of water over notches
To find head losses through pipes
Verification of Bernoulli’s theorem
1.7. Observations and Calculations:
To find out discharge, we have
Discharge = Volume \ Time
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𝐐=
𝐯
𝐭
TABLE NO. 01:
Discharge Calculations
S.No
Volume (liter)
Time (sec)
Discharge(Q)
1
25
20.29
1.2 lit\sec
2
25
20.54
1.21 lit\sec
3
25
21.43
1.16 lit\sec
Sump Tank
Flow Control
Valve
Motor ON/OFF
Button
Graduation
Scale
FIGURE 1: HYDRAULIC BENCH
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Experiment No. 02
“To Determine the Discharge and Coefficient of Discharge over
Rectangular Notch”
2.1. Apparatus:
•
•
•
•
Hydraulic Bench
Hook and Point Gauge
Stop Watch
Rectangular notch plate
2.2. Theoretical background:
Notch:
An opening in a tank/vessel in which the top edge of opening lies above the water
surface. It is used to find discharge in open channel.
FIGURE 2: NOTCH
Orifice:
An opening in a tank/vessel in which the top edge of the opening lies below the water
surface. It is used to find discharge in open channel.
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Figure 3: Orifice
Rectangular Notch:
A rectangular weir is used to meter flow in an open channel. The head over the
rectangular weir is measured and correlated with the water flow rate through the
open channel (and over the weir). A rectangular weir equation gives water flow rate
as a function of head over the rectangular weir. The discharge can be calculated
with following formula.
Figure 4: Rectangular Notch
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2.3. Observation and Calculation
TABLE NO. 02:
S.No
Volume Time
Q
H2
H1
H=H2-H1 Log(Q)
1
20
17.29
1.156738 152
84
0.68
2
15
13.29
1.128668 150
84
0.66
3
15
15.4
0.974026 145
84
0.61
Log(H)
0.063235 -0.16749
-0.01143 -0.21467
𝐶𝑑=0.76
0.8
0.6
y = 1.515x + 0.3141
0.4
0.2
0
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
-0.2
-0.4
-0.6
-0.8
Figure 5: Rectangular Notch
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Experiment No. 03
“Determine the Discharge and Coefficient of Discharge over
Triangular Notch”
3.1. Triangular Notch
A triangular notch is also called a V-notch. Consider a triangular notch, in one side
of the tank, over which water is flowing as shown in figure. Let, H = Height of the
liquid above the apex of the notch. θ = Angle of the notch.
Figure 6: Triangular Notch
To calculate discharge through triangular notch following formula is use.
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3.2. Observations and Calculations
TABLE NO. 03:
S/N0
Vol(L)
Time(sec)
𝑄𝑎𝑐𝑡(L/s)
𝐻1
𝐻2
𝐻
LogQ
1
30
50.54
0.593589
127
161
34
-0.2265 1.5315
2
20
58
0.344828
127
161
34
-0.4624 1.5315
3
10
129.8
0.077042
127
146
19
-1.1135 1.2788
LogH
0.5
0.3
0.1
-0.8
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
-0.1 0
0.1
-0.3
-0.5
y = 2.5764x + 0.7447
-0.7
-0.9
-1.1
-1.3
FIGURE 7: GRAPH OF FLOW OF THROUGH TRIANGULAR NOTCH
𝐶𝑑 = 0.75
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Experiment No. 04
“Investigation of different types of flows using Osborne Reynold’s
apparatus by visual observation”
4.1. Objective:
In this experiment we investigated the type of flow, using the Osborne Reynolds apparatus.
4.2. Apparatus



Osborne Reynold’s apparatus
Hydraulic bench
Glass marbles.

FIGURE 8: OSBORNE REYNOLDS APPARATUS
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4.3. Types of Flow
Laminar Flow
The flow in which fluid moves in liquid particles moves in form of thin sheets in which the particles
are not intersecting the path lines of each other such type of flow is known as laminar flow. In this
flow streamlines follow parallel path. The dye remains easily identifiable as solid core, denote
steady condition.
R≤2000
Turbulent Flow
The flow in which liquid particles move in zig zag path and intersecting the path lines of each
other is called as turbulent flow. In this flow streamlines interacts and completely disperses in flow
of water, denotes highly unsteady condition.
R>4000
Transition Flow
The flow that takes place during the inter-conversion of laminar and turbulent flow is called
transition flow or transition zone between laminar flow and turbulent flow is called transition flow.
In this flow the streamlines interact and partial mixing of flow occurs. Dye form eddies while
flowing through water, denotes unsteady condition.
4000≥R>2000
FIGURE 9: FLOW TYPES
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4.5. Observations and Calculations:
TABLE NO. 04:
Serial No.
Observation
Type of flow
1
Solid line of dye
laminar
2
Discontinuity, partial mixing
transition
3
Dye disappears, complete mixing
turbulent
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Experiment No. 05
“Investigation of different types of flow by using Osborne Reynold’s
Apparatus by (Reynolds number formula)”
5.1. Apparatus:
•
•
•
•
Hydraulic Bench
Osborne Reynolds Apparatus
Dye Reservoir
Thermometer
5.2. Procedure:








Fill the dye reservoir with dye.
Then lowered the dye injector until it just above the bell mouth.
Turn on the pump to supply water to the head tank.
Slowly fill head tank to the overflow level.
Closed the inlet valve.
Open the control value so that the dye mixes with the water.
Open and close the velocity control valve to admit the water to the flow visualization pipe.
Open the inlet valve slightly until water travelled from outlet pipe.
5.3. Observations and Calculations:
Diameter of pipe = 1 cm = 0.01 m
Area of pipe = 0.0000785 𝑚²
Temperature of water = 25 ̊C
Kinematic viscosity of water =1.003x10−6 m²/sec
TABLE NO. 05:
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S.NO
Volume
(m3)
Time
(Sec)
Temperature
( ̊C )
Discharge
(m3/sec)
Reynolds Remarks
number
01
0.0002
87.05
20
0.029
289
Laminar
02
0.0008
20
0.25
2492
Transition
03
0.003
20
0.73
7278
Turbulent
40.00
51.78
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Experiment No. 06
“To Determine Theoretical and Actual Center of Pressure on
Partially Submerged Body”
6.1. Objective
To determine the theoretical and actual center of pressure
6.2. Apparatus
• Different Weights
• Hydrostatic pressure apparatus
• Graduated cylinders
6.3. Hydrostatic Force Theory
Fluid force is constant at any particular depth but varies vertically. This force is calculated as
liquid weight per unit volume times the depth. The total force exerted by the liquid on the ring
section is non-uniformly applied vertically. When the quadrant is immersed in water it is possible
to analyze the forces acting on the surfaces of the quadrant as follows: Hydrostatic forces on the
upper and lower curved surfaces therefore have no net effect – no torque to affect the equilibrium
of the assembly because all of these forces pass through the pivot. The forces on the sides of the
quadrant are horizontal and cancel out The hydrostatic force on the vertical submerged face is
counteracted by the balanced weight W. The resultant hydrostatic force on the face can therefore
be calculated from the value of the balance weight and the depth of the water.
6.4. Centre of Pressure
All submerged surfaces experience a hydrostatic force. The point through which this force acts is
called the center of pressure. The total force vector acting at the center of pressure is the value of
the integrated vectoral pressure field. The resultant force and center of pressure location produce
equivalent force and moment on the body as the original pressure field.
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FIGURE 10: WEIGHT AND HYDROSTATIC PRESSURE APPARATUS
FIGURE 11: WEIGHT AND HYDROSTATIC PRESSURE APPARATUS
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6.5. Hydrostatic Centre of Pressure
The theoretical center of pressure can be calculated as
𝐇𝐩 =
𝟐
𝐲+𝐚
𝟑
Where
y = Depth of water
a = Distance of water level from pivot
6.6. Actual Centre of Pressure
𝑭𝒓 = 𝑷 ∗ 𝑨
𝒉𝒃
= 𝒓 ∗ 𝟐
=
𝟏
∗ 𝒉𝟐 ∗ 𝒃
𝟐𝒓
According to condition of equilibrium we know that
𝐖 ∗ 𝐋 = 𝐅𝐫 ∗ 𝐇𝐩
𝐇𝒑 = 𝐖 ∗
𝐋
𝐅𝐫
Where
W= weight
Fr= Resultant force
L = Moment arm =27.5cm
a= distance of water level from pivot=20-y
y= depth of water
r=9.81KN/m^3
6.7. Procedure:
Check the bench is leveled properly with the use of spirit level.
• Add a small mass (50g) to the weight hanger.
• Get tap water using steel vessel and fill up the flotation tank.
• Fill the floatation tank with water initially until the balance arm rises.
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• Continue to add water until the balance arm is horizontal, checking this by aligning the flat of
the balance arm with the central mark on the level indicator.
• When the arm is horizontal read the depth of immersion from the scale on the face of the
quadrant.
• Repeat the above procedure for different load increments by adding further weights to the weight
hanger
• Repeat the procedure in order to get accurate result.
6.8. Precautions
• First of all, clean the apparatus.
• Level the apparatus with the help of screws.
• Balance the apparatus.
6.9. Conclusion
By the above experiment we are able to determine the theoretical as well as actual center of
pressure on partially submerged body.
6.10. Observations and Calculations:
TABLE NO. 06:
S.No
Weight
(kg)
Depth of water
(mm)
Distance of water
level from pivot (q)
(mm)
Resultant
force
(N)
Hp (actual)
(mm)
Hp
(theoretical)
(mm)
1
0.05
45
155
0.74
181
185
2
0.10
66
134
1.60
172
178
3
0.15
83
117
2.53
163
172
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Experiment No. 07
“To determine the hydraulic coefficients (Cv, Cc and Cd) for small
circular orifice provided at the side of the tank”
7.1. Theoretical background
Orifice:
An opening in the vessel through which water flows is known as orifice. Orifice may small and
large depending upon the diameter of the orifice and the diameter of the vessel or tank.
 Orifice is used to determine the discharge through it. Discharge through the orifice depends
upon the head of the water above the center of the orifice which is denoted by “ho”.
 An orifice is called as small orifice when the diameter of the tank is larger than five times
the diameter of the orifice.
Vena contracta:
It is the portion of the jet with least diameter.
Hydraulic coefficients:
Hydraulic coefficients are three in number, denoted as Cc, Cd and Cv.
 The ratio of the area of the jet at vena contracta to the area of the orifice is known as
coefficient of contraction i.e. Cc.
Cc =
Ac
Ao
 The ratio of the actual discharge to the theoretical discharge is known as coefficient of
discharge i.e. Cd.
Cd =
Qact. Vol./time
=
Qth. Ao√2𝑔𝐻𝑜
 The ratio of the actual velocity to the theoretical velocity is called as coefficient of velocity
i.e. Cv.
Cd =
√2𝑔𝐻𝑐.
√2𝑔𝐻𝑜.
=
Hc
Ho
Do = Diameter of the orifice = 6mm
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7.2. Objective:
To determine the hydraulic coefficients and to study the jet profile.
7.3. Apparatus and parts of the apparatus:
i.
ii.
iii.
iv.
v.
vi.
vii.
Constant head inlet tank
Circular orifice
Hydraulic bench
Needle apparatus
Clip board
A3 size white paper sheet
Stop watch
Different parts of the apparatus are:
i. Turbulancy diminisher
ii. Orifice
iii. Supply
iv. Pipe for static head measurement
v. Micrometer and pitot tube
vi. Scales overflow
7.4. Procedure:
 Adjust the appartus which is going to be used in this very experiment.
 Open the inlet valve and adjust the inflow to make the head of the water above the orifice
be constant.
 Water will come from the orifice and the discharge i.e. actual discharge can be found by
using hydraulic bench volumetric tank and stopwatch to measure the volume and time and
the discharge will be found as:
𝑉𝑜𝑙.
𝑄𝑎𝑐𝑡 =
𝑡𝑖𝑚𝑒
 The water coming out of the orifice follow certain trajactory. This trajactory is traced by
using needles.
 The path is traced on an A3 size paper sheet.
 The coordinates of these points which are eight in number are then found in terms of x and
y coordinates.
 Needles are 5cm apart, so x distances will differ by 5 starting from zero.
 Then Cv is found by using the formula:
𝑋2
4𝑌𝐻𝑜
Cd is found by dividing the actual discharge by the theoretical discharge.
And at the last Cc is found from Cd and Cv already computed.
Here we cannot use the direct formulas for the computations of Cv and Cc due to the
limitations of the current experiment.
Repeat the same procedure for three times.
𝐶𝑣 = √




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7.4. Conclusion:
With the help of this experiment we found the hydraulic coefficients by using the formulas and
also studied the jet profile by using the needles arrangement.
FIGURE 12: NEEDLE APPARATUS AND CONSTANT HEAD INLET TANK
FIGURE 13: NEEDLE APPARATUS
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7.5. Observations and Calculations:
Table No. 07(a)
Reading No. 01:
Do = 6 mm
ho = 300 mm
Vol. = 3 lit.
Time = 76.22 s
Qact. = 0.0394 lit./s
Qth. = 0.0686 lit./s
X
Y
X2
0
0
0
5
0.75
25
10
1.75
100
15
3.2
225
20
5
400
25
7.45
625
Cc = 0.66
30
10.35
900
Slope = 93.077
35
13.3
1225
Cv = 0.869
Cd = 0.574
1400
1200
y = 93,077x - 48,828
1000
X2
800
600
400
200
0
-200
0
2
4
6
8
10
12
14
Y
FIGURE 14: RELATIONSHIP BETWEEN X2 AND Y
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
Reading No. 02:
Table No. 07(b)
Do = 6 mm
ho = 283 mm
Vol. = 2 lit.
Time = 56.87 s
Qact. = 0.03517 lit./s
Qth. = 0.06662 lit./s
Cv = 0.883
Cd = 0.528
Cc = 0.598
Slope = 88.321
X
Y
X2
0
0
0
5
0.7
25
10
1.85
100
15
3.4
225
20
5.6
400
25
7.95
625
30
10.8
900
35
14
1225
1400
1200
y = 88,321x - 51,579
1000
X2
800
600
400
200
0
0
2
4
6
-200
8
10
12
14
16
Y
FIGURE 15: RELATIONSHIP BETWEEN X2 AND Y
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
Experiment No. 8
“To determine the hydraulic coefficients (Cv , Cc and Cd) for a small
circular orifice provided at the bottem of the tank”
8.1. Theoretical background:
Orifice:
An opening in the vessel through which water flows is known as orifice. Orifice may small and
large depending upon the diameter of the orifice and the diameter of the vessel or tank.
Vena contracta:
It is the portion of the jet with least diameter.
Pitot tube:
It is a tube used to measure the static pressure head plus elevation head and also the velocity head,
kept in the direction of the upstream side.
8.2. Objective: To determine the hydraulic coefficients without studying the jet profile from
the proposed formulas. That is done by using a pitot tube.
8.3. Apparatus:
i.
ii.
iii.
iv.
v.
Hydraulic bench
Constant head inlet tank
Piezometer
Pitot tube
Stop watch
8.4. Procedure:
 Adjust the apparatus for the experiment.
 Open the inlet valve and maintain the head constant (at supply tank) over the orifice.
 Adjust the inflow in such a way that a constant head is maintained.
 Allow water to flow through the orifice and note the maximum head over the orifice that
permits the water jet to flow into the measuring tank.
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
 Regulate the inlet valve to obtain a constant head over the orifice and note the time taken
for collecting water to a height ‘h’ in the measuring tank.
 Then calculate the actual discharge by dividing the volume collected by time.
 Revolve the micrometer of the pitot tube and bring the hollow needle to the center of the
jet flow so that velocity head can be calculated.
 To measure the
diameter at the vena
contracta revolve
the micrometer from one
side of the jet to
the other side and note
the
number
of
revolution
micrometer
as
one
1mm movement
of
the
revolution
gives
to the hollow needle.
 So in this way
calculate the diameter of
vena contracta.
FIGURE 16
8.5. Observations and Calculations:
Table No. 08:
S.No.
Do
(mm)
Dc
(mm)
ho
(mm)
hc
(mm)
Vol.
(lit.)
Time
(sec.)
Cv
Cd
Cc
01
02
14
14
12
358
372
354
367
15
15
56.41
56.58
0.994
0.993
0.652
0.638
0.735
0.862
13
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FINAL LAB. REPORT
03
14
FLUID MECHANICS-II (LAB.)
13
373
363
Department Of Civil Engineering UET Peshawar
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38.27
0.995
0.630
0.862
32
FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
Experiment No. 9
“To investigate the validity of Bernoulli’s theorem as applied to the
flow of water by Bernoulli’s theorem demonstration”
9.1. Theoretical background:
Bernoulli’s Theorem:
The total head of the flowing liquid between two points remains constant provided that there is no
loss due to friction and no gain due to an application of outside work between these two points.
Total head is given by:
𝑯=
𝒑 𝒗𝟐
+
+𝒛
𝜸 𝟐𝒈
Where;
p/ϒ = static pressure head
v2/2g = velocity head
z = elevation head
Flow control valve:
It is a valve used to control the amount of i.e. velocity of the fluid through a certain pipe or flow
channel.
9.2. Apparatus:
i.
ii.
Bernoulli’s Apparatus
Hydraulic Bench
9.3. Different parts of the Bernoulli’s apparatus:
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
ix.
x.
Air bleed screw
Monometer tubes
Unions
Gland nuts
Test section
Water inlet
Hypodermic probe
Water outlet
Flow control valve
Tapping Points
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
9.4. Procedure:
 Close the inlet and outlet valves.
 Open the air bled screw before starting the experiment.
 Slowly open inlet valve and the water will rise in the manometer tube and will escape
through air bled screw.
 Adjust the pressure in the pipes to remove the air bubbles by several trials.
 Adjust the pressure heads in the tubes.
 Find the actual static head with the help of the scales attached to the back of the tubes.
 Find the total actual head by using gland nut at each of the tapping points.
 Actual velocity head is calculated is from the above two heads.
 Theoretical static head is calculated as follows:
𝒑𝟐 𝒑𝟏 𝒗𝟏 𝟐 𝒗𝟐 𝟐
=
+
−
𝜸
𝜸
𝟐𝒈 𝟐𝒈
 The theoretical velocity head is given by:
𝒗𝟐
𝟖(𝒗𝒐𝒍. )𝟐
= 𝟐 𝟐 𝟒
𝟐𝒈 𝝅 𝒈𝒕 𝑫
 Theoretical total head is equal to the sum of these two heads.
9.5. Observations and Calculations:
Table No. 09:
Tapping Actual Actual Actual Theoretical
position static velocit total static/pressu
head y head head
re head
Theoretical
Velocity
head
Theoretic
al total
head
Head
loss
b/w
two
point
s
Total
head
loss
up to
point
s
A
244
2
246
244
3.3
247.3
1.3
1.3
B
209
36
245
209
34.2
243.2
4.1
5.4
C
150
94
244
150
65.5
220.4
22.8
28.2
D
143
98
241
143
97.4
240.4
20
48.2
E
92
147
239
92
127
219
21.4
69.6
F
132
33
165
132
33
165
54
123.6
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
Experiment No. 10
“To determine the relationship between head loss due to friction and
velocity of the flow of water through smooth bore pipe”
10.1. Objective:
To study the laminar flow and turbulent flow. With the help of this experiment we can determine
the head loss due to friction at different velocities and eventually obtain the relationship between
these two parameters.
10.2. Theoretical background
Head:
Head is defined as the energy of the fluid per unit weight of the fluid and its unit is “meter (m)”
in S.I.
Head loss:
Head loss due to friction is the loss of the head of fluid while flowing through a pipe (i.e. smooth
pipe in present case) due to the viscous effect in the fluid. The relationship for head loss due to
friction is given by Darcy Weisbach;
𝒉𝒇 =
𝒇𝑳𝒗𝟐
𝑫𝟐𝒈
Head loss and velocity relationship:
Its relationship depends on the type of the flow i.e. whether the flow is laminar or turbulent.
For laminar the relationship is given by;
𝒉𝜶𝒗
For turbulent flow the relationship is given by;
𝒉 𝜶 𝒗𝒏
10.3. Apparatus:




Fluid friction apparatus
Hydraulic bench
Stop watch
Thermometer
10.4. Parts of the fluid friction apparatus:
 Smooth bore pipe
 Artificially roughened pipe
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FINAL LAB. REPORT

















FLUID MECHANICS-II (LAB.)
Long and short radii bends
Y, elbow and T-joints
Sudden contraction
Sudden enlargement
Transparent pipe section with pitot tube
Transparent venturi meter
Transparent orifice meter
Ball valve
Isolating valve
Globe valve
Control valve
Gate valve
Water inlet and outlet
Strainer
Pressure tapping points
Tubing and connectors
Flexible tubes and monometer
FIGURE 17: FLUID FRICTION APPARATUS
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FINAL LAB. REPORT
FLUID MECHANICS-II (LAB.)
10.5. Procedure:








First of all remove air from pipes i-e open all valves
Now close all valves except the pipe under observation
Close the screw above the mercury manometer such that all air is removed
Close the isolating valve
Not the head loss from the difference in mercury column of mercury manometer
Measure the discharge of water from outlet by graduated beaker and stopwatch.
Increase the velocity of flow from inlet control valve and repeat the process again
Thus we can observe that by increasing the velocity of flow of water, the head loss increase.
10.6. Observation and Calculations:
Table No. 10:
S.no
1
Diameter(mm)
2
3
1
6mm
2
3
1
10mm
2
3
17mm
Volume(lit)
1
1
2
10
10
10
10
20
20
Time(sec)
43.7
8
25.9
9
44.02
76.17
56.65
43.09
21.72
29.68
25.36
Discharge(lit/sec
)
.023
.038
5
.0454
.131
.176
.232
.46
.67
.78
Velocity(m/sec)
.801
1.36
1.61
1.67
2.25
2.25
2.03
2.97
3.48
Reynolds No
5757
9729
1147
1
20,47
6
26,75
0
35,17
9
41,08
5
6010
7
7034
8
Friction factor(f)
.036
.031
.029
.0256
.024
.0225
.0217
.0199
.0192
Measured head
loss(mm)
198
490
653
365
617
1000
456
895
252
Calculated head
loss(mm)
130
241
351
142
184
295
84
348
397
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