Application of a cubic pressure-strain correlation to turbulent flow over sand ripples

Predictions of turbulent flow over a train of immobilized two-dimensional asymmetric bed forms are presented. The results from a differential second moment (DSM) closure turbulence model, based on the assumptions of high-Reynolds-number turbulence, are compared with experimental data. The resulting transport equations are solved by a collocated finite volume scheme. The results obtained here demonstrate major improvements in the predictions of near-wall turbulent kinetic energy and Reynolds stresses compared with previous work. This is attributed to the application of a Cubic Quasi-Isotropic Model (CQIM) for the mean-strain part of the pressure-strain correlation. Induced roughness as a function of bed form steepness was calculated and shown to be in good agreement with the experimentally determined values of Van Rijn (1982).