Author(s): H. C. Dai; L. L. Wang
Linked Author(s): Lu Wang
Keywords: Bed load; Experiment; Step-pool system; Flow energy; Mountain stream
Abstract: In this study, three dimensional density currents were first calculated by the improved delay detached eddy simulation (IDDES) model proposed by Shur (2008) based on the k ω− model with the additional buoyancy terms. The turbulent flow equations of mass, momentum, concentration and the IDDES model were implemented in the σ-coordinate and the operator splitting methods were used by the collocated-grid finite difference methods. The model has been verified with the experimental data. Comparison of the computed time averaged velocity and the height of density currents with the experimental data illustrates a better agreement by the IDDES model with the buoyancy effects than that of k ω− model with the buoyancy terms. The results showed that the IDDES model has the ability to resolve the evolution and breakup of vortices in the shear layer of density currents and can give an instantaneous mixing process of density currents and clear water. As a result, the IDDES model has the potential ability of the application in density currents.
Year: 2013