Numerical study of Horseshoe Vortices around a cubic obstacle in a channel

초록

Laminar horseshoe vortices in an internal flow are investigated using numerical simulation. We consider flows between two parallel plates with a cube mounted on the lower wall. The objective of this study is to clarify both the steady and the unsteady characteristics of the horseshoe vortex system generated in an internal flow. As the Reynolds number increases, the structure of the horseshoe vortex system becomes complex and the number of vortices increases. The distribution of skin friction on the cube-mounted wall reflects the effect of the horseshoe vortices. Unsteady laminar horseshoe vortex systems are hardly found as long as the upstream flow is fully viscous. They are obtained when the cube is placed in the inviscid core region. The unsteady horseshoe vortex systems are characterized by the repeated processes of generation, translation, and mutual merging. Topological studies of the current numerical results reveal that evolution of the vortical structures in internal juncture flow strongly depends on the Reynolds number.