Effects of wall-normal grid refinement and grid-topology on wall pressure fluctuations in wall-modeled large-eddy simulations

This work provides evidence of improved predictions of several one- and two-point statistics, including wall-pressure fluctuations and its spectrum from wall-modeled large-eddy simulations of a turbulent channel flow at Re_τ = 2000, when using isotropic grids in contrast to wall-normally refined grids. Secondly, it is shown that using truncated octahedral grids over Cartesian grids also improves the aforementioned predictions. With the octahedral grids, the overall convection speed of the wall pressure fluctuations is found to agree reasonably with reference DNS. Further, the mean velocity profile and the turbulence intensities (including those of the wall-pressure) are predicted reasonably irrespective of the location of the interface between the outer LES and the wall model. This marks an improvement over the commonly reported log-layer mismatch observed with Cartesian grids.