Large-eddy simulation of flow over a surface-mounted prism using a high-order finite-difference scheme

Large eddy simulation (LES) of the flow field over a surface-mounted prism under two different conditions, namely smooth and turbulent inflows, are carried out. A higher-order scheme, in which artificial dissipation is controllable, is used. The simulations are validated through comparison with experimental measurements. The results present new physical aspects and details regarding the development of the primary separation flow on the upwind face of the prism, the development of the horseshoe vortex flow, the primary and secondary separations of the reversed flow on the roof, and finally the locations of the highest suction pressures (in the mean) on the roof and the sides of the prism with respect to the secondary separation lines. The effects of the incident turbulence are determined by pointing out differences in the flow topologies between the two incident flow cases. Based on the validation with the experimental results, the compact upwind difference fifth-order scheme, used here, is recommended for performing LESs of complex flows.