Numerical simulation of flow around a circular cylinder having porous surface

Flow around a circular cylinder having porous surface is studied numerically by means of direct numerical simulation and large eddy simulation. The flow in the porous media is represented by a spatially averaged model. First, the properties of the most effective porous media are found from a preliminary two-dimensional parametric test. Subsequently, the dependency of flow modification on the Reynolds number (Re = 100, 1000, 3900, and 1.0 × 10⁵) and the porous layer thickness is investigated in detail. It is found that the porous surface works to suppress the velocity and pressure fluctuations and such effect is more significant at higher Reynolds number. In particular, the vortex shedding is found to be completely suppressed at Re = 1.0 × 105. The mechanism of flow modification is explained by slip velocity and energy dissipation process.