This document summarizes an experiment on open channel flow to develop generalized specific energy and specific force curves. The objectives are to observe flow profiles and plot the curves from observed data. Specific energy and forces are explained. The apparatus includes a tilting flume, manometer, and hook gauge. Procedures describe maintaining discharge and measuring depths at slopes. Graphs show the specific energy curve developed. Precautions ensure accurate measurements. Applications include determining weir heights, flume widths, and sluice gate openings.

1. Course Name:
OPEN CHANNEL FLOW SESSIONAL
Course No.: CE-3202 Credit: 0.75

2. Presented by:
Arafat Hossain Jibon
ID: 161102
Session: 16-17
Section-B
Department of Civil
Engineering, DUET

3. Presented to:
Prof. Dr. Mohammed Alauddin
Department of Civil Engineering, DUET
Ms. Rokshana Pervin, Asst. Professor
Department of Civil Engineering, DUET
Dhaka University of Engineering & Technology, Gazipur 1707

4. Presentation on
Development of generalized specific energy and
Specific forces curves

5. CONTENTS
Background
Objectives
Theory
Apparatus
Graphs
Procedures
Precaution
Application
References

6. Background
• The experiment of specific energy and specific force is
extremely useful in the solution of many problems in
open channel flow.
• This experiment deals with the development of
generalized specific energy and specific force curves.
• These curves are useful in determining the state of flow
in a channel, i.e. whether the flow is critical, subcritical or
supercritical.

7. OBJECTIVES:
• To observe the flow profile in the experimental setup
which depicts the variation of depth with change in
energy.
• To plot the generalized specific energy and specific
forces curves from the observed data.

8. THEORY
Specific Energy
It is the total energy per unit weight measured relative to the channel bed. E = y+(V^2)/2g

11. Alternate Depths
For any value of Specific energy other then at the critical point for a constant discharge,
there are two water depths, one is greater then the critical depth and the other is less then the critical depth.
These two depths for a given specific energy are termed as specific depths.

12. APPARATUS
• S-6 Tilting laboratory flume with manometer,
slope adjusting scale and flow arrangement.
• Hook gauge (to measure depth of water).

13. Procedure
• Maintain constant discharge in the open channel.
• For one particular value of slope find out the water depths at three
different locations and calculate the average depth of flow .
• Calculate the specific energy using relationship.
• Repeat this procedure for different values of slope.
• Draw the specific energy curve.
• Find out the critical depth and Emin
• Find out yc theoretical and Emin theoretical.

14. GRAPHS
Fig: Specific-energy curve

20. Data Sheet
12.9 12.9 12.9 12.9 6.55 7.56 21.59
2.6 2.3 2.2 2.367 1.2 1.55 1.55
1.9 1.8 1.4 1.767 0.89 1.52 1.52
1.2 1.2 1.2 1.2 0.61 1.96 1.83
1.1 1.1 1.1 1.1 5.56 2.17 1.95
1.2 1.2 1.2 1.2 0.61 1.96 1.83
15 15 15 15 7.6 7.62 29.12

21. Precautions
1) Tip of the hook gauge should just touch the water.
2) Take piezometric readings when flow is ready.
3) Take more then three readings.

22. REFERENCE
• https://civilengineerspk.com/testsexperiments/hydraulic-
engineering-experiments/exp-2-specific-energy-flow-depth/
• Chow,V.-T.(1959).Openchannelhydraulics,McGraw-Hill,NewYork
• Mossa,M.(1999).Ontheoscillatingcharacteristicsofhydraulicjumps,Jo
urnalofHydraulicResearch,37(4),pp.541-558
• Streeter,V.L.(1971).Fluidmechanics,McGraw-Hill,NewYork.
• Chapter-3,openchannelflow,ven te chow.

23. Application
• For determining the height of a weir
• For determining the width of a flume
• For determining the opening of sluice gate