Darcy’s law & chezy’s law

It's only for fluid mechanics. Those are need to know about Darcy’s law & chezy’s law

1. Presentation on Darcy’s & Chezy’s formula for loss of head in simple pipes By Group 1 1

2. Member of Group Md.Ariful Islam--------10307044 Nur -E- Alam Siddike ---10307050 Abu Bakar Siddique ---10307076 Mahadi Hasan Rubel ---10307059 Arfan Hossain ----------11170119 2

3. Objective Know the formula Describe the formula Application of formula Importants of formula 3

4. Head Loss Major Losses losses due to friction Minor Losses entrance and exit sudden change of cross sections valves and gates bends and elbows ect 4

5. Darcy’s Biography 5

6. Dracy’s law When the water is flowing in a pipe, it experiences some resistance to its motion, whose effect is the velocity and ultimately the head of water available. An empirical formula for the loss of head due to friction was derived by Henry Darcy 6

7. Darcy’s law h f = Loss of head due to friction L = Length of pipe D= Diameter of the pipe 7

8. Darcy’s law 8

9. Darcy’s law Let, l= length of the pipe D= diameter of the pipe v= Velocity of water in the pipe f'= Frictional resistance per unit area at unit velocity Consider sections (1-1) and (2-2) of the pipe Let, p 1 = Intensity of pressure at section (1-1) p 2 = Intensity of pressure at section (2-2) 9

10. Darcy’s law 10

11. Chezy’s Biography Chézy was born at Chalon - sur -Marne, France, on September 1, 1718, and died on October 4, 1798. He retired in 1790 under conditions of extreme poverty. It was not until 1797, a year before his death, that the efforts of one of his former students, Baron Riche de Prony , finally resulted in Chézy's belated appointment as director of the Ecole des Ponts et Chaussées . 11

12. CHEZY’S LAW Chezy Formula : Can be derived from basic principles. It states that 12

13. V is velocity R is hydraulic radius S is slope of the channel C is Chezy coefficient and is a function of hydraulic radius and channel roughness 13

14. chezy’s law 14

15. chezy’s law Let, l= length of the pipe D= diameter of the pipe v= Velocity of water in the pipe f'= Frictional resistance per unit area at unit velocity Consider sections (1-1) and (2-2) of the pipe Let, p 1 = Intensity of pressure at section (1-1) p 2 = Intensity of pressure at section (2-2) 15

16. Darcy’s result 16

17. Figure from Hornberger et al. (1998) 17

18. Figure from Hornberger et al. (1998) Generalization of Darcy’s column  h/L = hydraulic gradient q = Q/A Q is proportional to  h/L 18

19. Figure from Hornberger et al. (1998) Linear flow paths assumed in Darcy’s law True flow paths Average linear velocity v = Q/An= q/n n = effective porosity Specific discharge q = Q/A 19

20. Inflow = Outflow Recharge Discharge Steady State Water Balance Equation Transient Water Balance Equation Inflow = Outflow +/- Change in Storage Outflow - Inflow = Change in Storage 20

21. USE OF DERCY’S AND CHESY’S FORMULA Power generation Mining Refrigeration Vehicles Water supply drainage system etc. 21

22. THANKS TO ALL. 22