Assessment of wall models in large eddy simulation of turbulent separation bubble with and without sweep

Wall-modeled LES of turbulent separation bubble over a flat plate is conducted using three wall models: ODE equilibrium, integral nonequilibrium, and PDE nonequilibrium wall model. The flow configuration is based on the two DNS studies of Coleman et al. (J. Fluid Mech. (2018), vol. 847, 28-70, and J. Fluid Mech. (2019), vol. 880, 684–706), where suction and blowing from the top results in a pressure-gradient-induced separation bubble at the bottom wall. The incoming freestream velocity vector is unswept in the former case, and swept at 35° to the pressure-gradient vector in the latter. These two cases allow us to assess the performance of wall models in 2D- and 3D-turbulent-boundary-layers undergoing separation, the latter being more representative of practical flows. Mean velocity, boundary layer integral quantities, wall shear stress predictions, and skewness of profiles from WMLES will be analyzed to explore how the differing physics in the two cases affect different wall-models.