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Reynolds Averaged Navier-Stokes equations (RANS) were solved for three cases, namely, flow over a half cylinder in a uniform stream, near a stationary wall and near a moving wall. Time accurate, incompressible computations were performed for a Reynolds number of half-a-million. Computed time histories of force coefficients exhibit a strong tonal nature representative of regular periodic shedding. The effect of the ground on the periodic shedding was studied and the computational results were compared with experiments for the free stream and stationary wall cases. Strouhal number computed from the computational simulations agrees well with the experimental results. Time averaged pressure distribution on the body and wall show reasonable agreement with experimental data.

Effects of boundary conditions on the computational simulation of time dependent flows is studied. In particular, the effect of various boundary conditions for the flow over a half circular cylinder which is known to exhibit periodic shedding under certain conditions is investigated. A type of convection boundary condition called the radiation boundary condition is demonstrated to eliminate the secondary frequency which contaminates the solution due to the partial reflection of the fluid structures at the exit plane. However, the boundary condition implementation comes at the additional cost of storing results corresponding to three time levels.