Wall modeled large-eddy simulations of flow over the Sandia Axisymmetric Transonic Bump

Wall-modeled large-eddy simulations (WMLES) are conducted for the flow over the Sandia Axisymmetric Transonic Bump (ATB) at bump chord Reynolds number, Re = 1x10^6 and Mach number, Ma = 0.875. Utilizing various subgrid-scale and wall models, comparisons are made between the simulations and experiments for quantities of engineering interest, such as the skin friction coefficient (Cf) and wall pressure coefficient (Cp) data. Favorable agreements between the simulations and the experiments are achieved, with the simulations predicting the shock location, size, and strength of the separation bubble with reasonable accuracy. In particular, it was established that the realism of the incoming turbulent boundary layer onto the bump is very important for the correct and robust prediction of the skin friction in the upstream region of the bump. Furthermore, a resolution limitation on the predictive capability of the equilibrium wall model in the favorable pressure gradient region is established. Finally, preliminary results utilizing a pressure-gradient inclusive modification to the equilibrium wall model predicts the skin friction within the separation bubble at affordable resolutions