Numerical Computation of Turbulence Development in Flow Over Sand Dunes

摘要: The spatial development of sub-critical, turbulent, open-channel flow over a bottom with five dunes is studied. steady-state described by the RANS equations utilizing k−ɛ turbulence model. free-surface treatment based on rigid-lid approximation method, while numerical solution finite-volume discretization. Froude number Fr=0.3, both smooth and rough cases are considered. Mean velocity predictions in good agreement to available experimental data analytical expressions. Then, results presented for streamwise eddy viscosity, Reynolds stresses production bed train fixed dune length water depth ratio L/d = 5 height h/d 0.25. Numerical compared overall satisfactory. Turbulence generated mostly separation at crest does not reach an equilibrium state dunes.