Large Eddy Simulation of Separated Flow over a Wall-Mounted Cube

Large eddy simulation of flow over a wall-mounted cube in a channel was performed at a Reynolds number of 40000. The structure function modeling of the subgrid-scale stress terms was used with three slightly varying versions of its selective type. The convective terms were discretized using a QUICK scheme, along with a relatively coarse grid. A series of time-averaged velocities and turbulent stresses were computed and compared with experimental data to examine the performance of these models. The structure function model yielded deficient mean flow structure and turbulence statistics compared with the selective structure function. While none of these models could reproduce experimental results exactly, the results of time-averaged streamline plots and turbulent kinetic energy for one of the selective structure function models showed less discrepancy with experimental data compared with other models. It was shown that implementation of a wall function does not improve the results considerably and, in general, with a coarse grid resolution, it is possible to obtain some reasonable results as compared to the experiment.