m MONTAZERI-NAMIN - MSc Candidate of Hydraulic Structures, University of Tehran, Tehran
R. S. GHAZANFARI-HASHEM - Department of Civil Engineering, College of Engineering, University of Tehran
m GHAEINI-HESSAROEYEH - Department of Civil Engineering, College of Engineering, Shahid Bahonar University of Kerman

This study investigates the three-dimensional numerical modeling of supercritical flow in contractions in which the usual hypothesis of hydrostatic pressure is not held. Here, a very accurate commercial finite volume model, Fluent, is adopted for solving the Reynolds Averaged Navier-Stocks equations. The model verification consists of comparing computed results using the numerical model with Anastasiou et al.’s analytical solution for a one side contraction. Result showed that the model is adequate to address hydraulic problems involving oblique shocks. The CFD analysisis carried out on a channel contracting at a convergence angle of 6 degree at both sides. The volume of fluid (VOF) model is used to simulate the air-water interaction at the free surface and the turbulence closure was obtained using the standard k -e turbulence model. Finally, the results of numerical model are compared with available experimental data of supercritical flow in the described contraction. Simulated results of the free water surface in the contraction are in good agreement with laboratory data. Results of the study clearly demonstrate the strengths of usingCFD as an alternative or compliment to physical modeling.

Contraction, 3D Numerical Modeling, Open Channel Flow, Supercritical Flows, VOF Method