Numerical Simulation of Separated and Reattached Flows around a Backward-Facing Step

Separated and reattached flows around a backward-facing step (BFS) controlled by continuous suction was numerically investigated using the turbulence model of large eddy simulation (LES) based on the dynamic kinetic energy sub grid-scale model. The effect of suction control on the flow fields was described by the suction flow coefficient, and the results indicate that suction is not only very effective in shortening the reattachment length, but also very influential in reducing the turbulence fluctuations of the reattached flows. With increasing increments of the absolute suction flow coefficient, the effect of suction control is more significant. Furthermore, comparisons of the time-averaged statistics between the numerical simulation and corresponding experiment are conducted, and it shows that the LES can acquire exact results. Therefore, feasibility of the numerical methods to simulate suction-controlled models is validated.