Passive Flow Control Around a Semi-Circular Cylinder Using Porous Coatings

In this paper, the passive control of flow past a semi-circular cylinder is investigated. This control is achieved by adding a porous medium between the solid obstacle and the incompressible fluid in order to reduce drag forces and regularize the flow. A vortex-penalization method is chosen to easily model the flow in the different media. Several configurations of the porous layer are investigated and parametric studies are performed in order to determine the most efficient passive flow control devices. This control study can be considered as a first step to propose efficient strategies to regularize the flow around a side-view mirror. Nomenclature CD drag coefficient D computational domain F , S fluid domain and solid domain FD drag force Re Reynolds number Z enstrophy d non-dimensional diameter h reference mesh size k intrinsic permeability lre f height of the obstacle ure f reference velocity u = (u,v) velocity field us body rigid motion ū mean velocity magnitude u∞ free stream velocity ΓD computational domain boundaries ∆t time step Φ porosity λ penalization parameter μ dynamic viscosity ν kinematic viscosity ρ density of the fluid τ porous layer thickness χS characteristic function ω vorticity field