Near-wall patch wall-model for large eddy simulation

Wall-modeled large-eddy simulation (WMLES) requires predicting the near-wall stress, which is imposed as a boundary condition at the wall. Most wall models employ simplified formulations of the Reynolds-averaged Navier-Stokes equations (RANS) near the solid boundary, further supplemented with empirical closures. RANS-based wall models rely on averaged flow quantities without utilizing the available information about the structure of wall-bounded turbulent flows. We present a wall model based on a near-wall patch simulation that accurately resolves the near-wall flow structure. The patch’s domain size scales in inner units such that its cost is Reynolds number independent. The patch’s top boundary condition is derived from statistical constraints extracted from the LES and structural rescaling of its velocity field. The resulting wall-shear stress predicted by the patch is applied as the boundary condition to the LES, closing the system without utilizing a-priori fitted coefficients. Additionally, the patch provides predictions beyond the wall-shear stress and the subgrid mean velocity profile, such as velocity and pressure fluctuations below the first LES grid cell. The new wall model system is tested in various flow environments.