Research on the Vortex Structures of Flow around Surface-Mounted Obstcales

Abstract

The large eddy simulation (LES) method was employed to compute the flow past three types of obstacles on slope surface. The predictions give profile of mean velocity and flow reattachment length. The calculations in present paper are in good agreement with the experimental data. Wake characteristics are analyzed. The computational results show that the horseshoe vortex are formatted at upstream base of obstacles. The wake flow is controlled by the downwash flow on the free end, as well as, the upwash flow in the wake disappears completely. With the angle between the leeward side and the bottom becomes larger, the length of the vortex separation becomes larger, and the scope of vortices greater. The large eddy simulation can obtain almost all the flow pattern observed by the experiments.