Sensor-based blended wall-modeled LES of the flow over a NASA hump*

Wall-bounded flows subjected to pressure-driven relaminarization present significant challenges for wall-modeled large-eddy simulations with equilibrium wall models, which assume the boundary layer to be fully turbulent, leading to inaccurate predictions of skin friction. We present a numerical study of the relaminarizing flow over the NASA wall-mounted hump that applies a recently introduced blended wall-modeling approach that integrates a local relaminarization sensor. This sensor-based blended wall model, previously validated on the relaminarizing flow over a Gaussian-shaped bump geometry, blends an equilibrium shear-stress wall model with a laminar wall model, incorporating hysteresis time along fluid pathlines. We analyze the configuration with a freestream Mach number of 0.2 and a Reynolds number Re_θ≈7000 based on the momentum thickness of the flow upstream of the hump. Results will be compared with experimental data from Greenblatt et al. (2006) and Naughton et al. (2006), as well as WRLES results from Uzun & Malik (2017). The mean velocity and stresses in the target region will be analyzed to characterize the flow features. A systematic study regarding the effects of the wall-model exchange height and the grid resolution will be presented.