APPLICATIONS OF LARGE EDDY SIMULATIONS WITH FREE SURFACE TO FLOWS NEAR A GROYNE

摘要

Three-dimensional flows around a non-submerged groyne were computed numerically using Large Eddy Simulation (LES) and were investigated experimentally. Based on Smagorinsky model, a dynamic LES model along with a pressure Poisson equation for free surface flow was proposed to model secondary flows near a groyne. All these vortex flows around the groyne, which probably affect the whole flow field, were numerically simulated and analyzed. The strength of the largest circulating flow caused by the groyne behind it was weak. The analysis of the predicted shear stress field near the channel bed bottom presents a particular interest for studying the sediment transport around the groyne. The finite volume method (FVM) was used to discretize the Navier-Stokes equations and the SIMPLEC algorithm was used to solve them. Meanwhile, these flows were investigated experimentally in a 2-meter wide flume with a groyne fixed along the flume side. All the computational results were in fairly good agreement with the experimental data.