A Laboratory study of Velocity profile at Hydraulic Jump on Triangular Corrugated Bed

Document Type : Original Article

Authors

Abstract

In the present research, the hydraulic jump characteristics were studied experimentally over five triangular corrugated beds at the Hydraulics Laboratory of the Department of Water Engineering, University of Shahrekord, Iran. The flume has the dimensions of 0.4 m wide, 0.4 m deep and 12 m long. A total number of 15 tests were carried out for the range of initial Froude number from 6.1 to 13.1. In all tests, effect of triangular corrugated bed on velocity profiles and energy dissipation were studied. The dimensionless hydraulic parameters were determined as a function of the Froude number. The analysis of velocity profiles at different sections of the jump showed that the velocity profiles were similar and different from the profile of the simple plane wall jet. The normalized boundary layer thickness δ/b was equal to 0.39 for jumps on corrugated bed compared to 0.16 for the simple wall jet. It was also found that for similar Froude number the energy loss of jump on corrugated bed is more than the smooth bed (average=11.3%).

Hydraulic jump, Triangular corrugated beds, Velocity profiles, Energy loss.

1- ایزدجو، ف. 1383. تاثیر مواج بودن بستر بر روی طول پرش و نوسانات زیر فشار در حوضچه‌های آرامش از نوع پرش هیدرولیکی. پایان‌نامه‌ی دکترای سازه‌های آبی، دانشکده‌ی مهندسی علوم آب، دانشگاه شهید چمران اهواز.
2- Abbaspour, A., A. Hosseinzadeh Dalir,D. Farsadizadeh and A.A. Sadraddini. 2009. Effect of sinusoidal corrugated bed on hydraulic jump characteristics. Applied Sciences 9(11):2045-2055.
3- Ead, S.A., N. Rajaratnam, C. Katopodis and F. Ade. 2000. Turbulent open channel flow in circular corrugated culverts. Hydraulic Engineering 126(10):750-757.
4- Ead, S.A. and N. Rajaratnam. 2002. Hydraulic jumps on corrugated bed. Hydraulic Engineering 128(2):656-663.
5- Hager, W.H. 1992. Energy dissipators and hydraulic jump. Kluwer academic Publishers.
6- Izadjoo, F. and M. Shafai Bejestan. 2007. Corrugated bed hydraulic jump stilling basin. Applied Sciences 7(8):1164-1169.
7- Peterka, A.J. 1983. Hydraulic design of stilling basins and energy dissipators. Engineering Monograph No. 25, U.S. Bureau of Reclamation, Denver. Seventh Priinting.
8- Rajaratnam, N. 1968. Hydraulic jump on rough bed. Trans. Eng. Inst. Canada 11:1-8.
9- Shafai Bejestan, M. and K. Neisi. 2009. A New Roughened Bed Hydraulic Jump Stilling Basin. Applied Sciences 2(5): 436-445.
10- Tokyay, N.D. 2005. Effect of channel bed corrugations on hydraulic jumps. EWRI, Water & Environmental Resources Congress, Anchorage, Alaska, USA.