DEVELOPMENT OF GENERALIZED SPECIFIC ENERGY AND SPECIFIC FORCE CURVES
- 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.
- 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