ANALYSING TURBULENT BACKWARD-FACING STEP FLOW WITH THE LOWPASS-FILTERED NAVIER-STOKES EQUATIONS

High Reynolds number turbulent backward-facing step flow is studied using the large-eddy simulation technique proposed by Schumann. Central differencing on an equidistant cartesian grid and explicit time integration are chosen to predict the complicated flow structure. The comparison with experimental data indicates good agreement for the statistical quantities. Part of the disagreement is certainly due to scatter in the experimental data. Nevertheless, the results of the simulation may be further improved using globally or locally refined grids. Valuable information on the instantaneous flow behaviour in the free-shear layer and the reattachment zone is obtained from the simulation.