Document Type : Research Paper
Authors
1 Department of Technical Engr., University of Mohaghegh Ardabili, Iran
2 Research Department, Ardabil Regional Water Co., Iran
Abstract
Water supply from rivers is accomplished with flow diversion through an intake structure. A lateral intake like bifurcation is the simplest method to withdraw water. However, flow at a channel bifurcation is turbulent, highly three-dimensional (3D) and so has many complex features. This paper reports a 3D numerical investigation of these features in an open channel flow. Simulations have been done on rectangular channel geometry, with smooth bed and sidewalls. The standard k-ɛ, k-ω model of the Wilcox, and RSM turbulence models are compared using the commercial code FLUENT. The simulation results have been compared with available experimental data. It was found that all of the turbulence models tested here accurately predicted velocity profiles in the main channel but in the branch channel, the RSM model with the k-ω model performing better than the k-ɛ model. Predicted flow physics are in close agreement with previously reported experimental results.
Keywords
Barkdoll B., Sediment control at lateral diversion, PhD dissertation, University of Iowa, (1997).
Celik, I.B., Introductory turbulence modeling, Western Virginia University, (1999).
Fluent Inc., FLUENT user’s guide; Fluent, New Hampshire, (1993). Gibson M.M., Launder B.E., Ground effects on pressure fluctuations in the atmospheric boundary layer, Journal of Fluid Mechanics 86 (1978) 491-511. Launder B.E., Spalding D.B., Lectures in Mathematical Models of Turbulence, Academia press, London, England, (1972).
Launder B.E., Second-moment closure and its use in modeling turbulent industrial flows, International Journal of Numerical Methods in Fluids 9 (1989a) 963-985.
Launder B.E., Second-moment closure: present and future?, International Journal of Heat Fluid Flow 10 (1989b) 282-300. Lien F.S., Leschziner M.A., Assessment of turbulent transport models including non-linear RNG eddy-viscosity formulation and second-moment closure, Computers and Fluids 23 (1994) 983-1004.
Neary V., Odgaard A.J., Three-dimensional flow structure at open channel diversions", Journal of Hydraulic Engineering 119 (1993) 1224–1230.
Neary V., Sotiropoulos F., Numerical investigation of laminar flows through 90-degree diversion of rectangular cross-section, Computer and Fluids 25 (1996) 95-118.
Shettar A., and Murthy K., A numerical study of division of flow in open channels, Journal of Hydraulic Research 34 (1996) 651-675.
Taylor E.H., Flow characteristics at rectangular open-channel junctions, Transactions of the American Society of Civil Engineers 109 (1944) 893–912.
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