This document provides information about fluid mechanics experiments conducted by Group 1 of CEN 262. It lists the members of the group and then describes several key fluid mechanics concepts and experiments, including the importance of the center of pressure, Bernoulli's theorem, flow through a venturi meter and orifice, flow over a V-notch and rectangular weir, and the components used in experiments measuring flow through an orifice and mouthpiece. Diagrams and equations are provided to explain fluid mechanics principles and how the experiments are conducted.

1. FLUID MECHANICS
SESSIONAL
CEN 262

2. GROUP 1
1. CEN 069 10258 SUJIT KUMAR HALDAR
2. CEN 069 10262 TANMAY KRISHNA MAJUMDER
3. CEN 069 10263 RAHUL CHANDRA DAS
4. CEN 069 10264 SAJIB NAG
5. CEN 069 10265 SANTA CHAKRABORTY
6. CEN 069 10271 MUNMUN NAHER
7. CEN 069 10287 MD. IMRAN HOSSAIN IMON

3. IMPORTANCE OF CENTRE OF PRESSURE
Center of pressure is almost like the location of the resultant force of a system of forces or In plane surface
the centre of pressure is the point of application on which the resultant force is acting.
 Designing hydraulic structure
 Locating the actual point of centre of pressure
 Determining the effect of net force acting
Indeed the main thing which should be notable is that centre of pressure lies below centre of gravity of
body or coincides with centre of gravity and Centre of pressure is always measure from free surface of
liquid.

4. F I G U R E S
WATER CONTROL GATES
WATER DAM

5. BERNOULLI’S THEOREM
Daniel Bernoulli in the year 1983 stated that in a steady flow system of frictionless (or non-viscous)
incompressible fluid, the sum of pressure, elevation and velocity heads remains constant at every section,
provided no energy is added to or taken out by an external source. Thus,

6. F I G U R E S

7. FLOW THROUGH VENTURIMETER
 What is Venturi meter?
 Why it is used and where it is used?
 Which type of fluid can be measured by venturi meter?
 How does venturi meter calculate velocity?
Applications of Venturi Meter:
Venturi Meter is used in various field like-
 Calculating the flow rate of fluid that is discharged through the pipe.
 In the industrial sector, it is used to determine the pressure as well of the quantity of gas and liquid inside
a pipe.
 The flow of chemicals in pipelines.

8.  This is widely used in the waste treatment process where large diameter pipes are used.
 Also used in the medical sector for the measure the flow rate of blood in arteries.
 This also used where high-pressure recovery is required.
The advantages of Venturi Meter are:
 Power loss is very less.
 This can be used where a small head is available.
 High reproducibility (the extent to which consistent results are obtained when an experiment is repeated).
 Accuracy is high over wide flow ranges.
 This can also be used for a compressible and incompressible fluid.
 This device is easy to operate.
 The coefficient of discharge (Cd) for the venturi meter is high.
 This is widely used for a high flow rate (Discharge).

9. Although there are few disadvantages of venturi meter, and
those are:
 The installation cost of a venturi meter is high.
 There are little difficulties while maintenance.
 This device can not be used where the pipe has a small diameter of 76.2 mm.
 Non-linear.

10. FLOW THROUGH ORIFICE
An orifice may be sharp edged or bell mouthed depending
on the shape of the entrance edge. In the case of a sharp
edged orifice the inner edge (i.e., at entrance) is made
sharp and is tapered to a slightly larger diameter at the
outer edge. The liquid discharged through the orifice will
touch only the sharp edge at entrance.
In the case of a bell mouthed orifice, a rounded passage is
provided in the orifice and the discharge liquid will be in
contact with the entire inner surface of the orifice. Due to
decreased friction a bell mouthed orifice has a greater
discharging capacity.
The orifices mentioned above may discharge a liquid either from a tank into the atmosphere or from one tank
into another. If the liquid surfaces on the two sides of an orifice are above the upper edge of the orifice, then
the orifice is called a submerged or drowned orifice. If an orifice discharges a liquid to the atmosphere then the
discharge is said to be free.

11. ADVANTAGES
 An orifice plate is a device used for measuring flow rate, for reducing pressure
 It is cost-effective and quite easy to use.
 It occupies less space, making it ideal for space-constrained applications.
 It can also be used to determine flow rates in large pipes.
 It can be installed in the horizontal or vertical positions.
 It is used to measure the flow rate of fluids in their single state(i.e. gaseous state or liquid state).
 It can also be used to measure the flow rate of fluids in a mixed state (both gaseous and liquid states) such as,
wet steam, or natural gas with water.

12. MOUTHPIECE
 If a small tube is attached to an orifice, it is called
mouthpiece. The standard length of a mouthpiece is 3d,
where d is the diameter of the orifice.
 Mouthpiece is basically used in order to determine the
rate of flow of fluid.
 The effect of adding a mouthpiece to an orifice is to
increase the discharge.

13.  A mouthpiece decreases the pressure at vena-contracta and increases the effective head causing the flow,
hence, discharge is increased.
 But, for all practical purposes, the value of coefficient of discharge is taken as 0.855
 The discharge rate is increased due to a decrease in the pressure at vena-contracta within the mouthpiece
resulting in an increase in the effective head causing the flow

14. Uses of Mouthpiece
 Water Distribution System With Fixed Discharge
 To achieve higher value of Cd as compared to
mouthpiece.
 Water Treatment Plant.
 Liquid Food Industries.
 Car Wash Factory
And various types of Engineering plant, industries
etc.

15.  Single phase power supply: 220 volts, 50 Hz, 5 amp.
 Discharge measuring tank.
 Adjustable overflow arrangements.
 Variable head tank.
 Flow measuring scale.
 Mouthpiece.
Components
Orifice & Mouthpiece Apparatus

16. FLOW OVER V-NOTCH
 The V-notch design causes small changes in discharge to have a large change in depth allowing more accurate
head measurement than with a rectangular notch. Triangular notch more accuracy when discharge charge is
small.
 Ventilation of triangular notch is not necessary. Triangular notch will provide more precise results during
measuring low discharge as compare to result obtained from rectangular notch.
 3. V- notches are easily constructed and well-defined lab calibration.
 4.Open channel water flow monitoring is widely used in environmental and geotechnical fields.
 5.In principle simple v notch weir is a low cost and powerful device that is ideal for long dams.
 6.It is also used in drainage systems in tunnels and excavations.
Importance of Flow over V-notch experiment :

18. FLOW OVER SHARP CRESTED
RECTANGULAR WEIR
A weir is an overflow structure built across an open channel for the purpose of
measuring the flow.
Sharp crested weirs are generally used to measure the discharge in small open
channels where accuracy is required.

19. PRACTICAL APPLICATION AND IMPORTANCE
In general, sharp-crested weirs are used in hydraulic laboratories, industry and irrigation pilot schemes where
highly accurate discharge measurements are required
Many times a flow measuring weir is simply a thin plate across a flow stream, but weirs can also be broad,
thick structures. The thin plate weir is usually used to measure watersheds, creeks, and small streams.
The data found after the calculation over a rectanguler sharp-crested weir can be used in many ways. Such as,
 Flood control and general water management policies are often designed on the basis of such data.
 The data can be used to determine if a hydroelectric project would be possiible or profitable.
 Irrigation is also benefited from this kind of area.

20. F I G U R E
Aerated weir
Unaerated weir

21. THANK YOU
Group-1, 69B