Grid Dependence of Wall-Modeled RANS Simulations

The paper investigates the influence of the consistency between the law-of-the-wall and turbulence models on the grid dependence of wall-modeled Reynolds-averaged Navier–Stokes (WM-RANS) simulations. It is shown that using a wall function consistent with the turbulence model improves the accuracy of the WM-RANS solution compared to most known wall functions, as it approximates the boundary layer in the buffer zone more accurately. A consistent wall function is constructed for the Spalart–Allmaras turbulence model. The independence of the WM-RANS solution on the grid resolution and the matching location between the law-of-the-wall and the outer turbulent boundary layer solutions is demonstrated for the Spalart–Allmaras turbulence model with the consistent wall function for the zero-pressure-gradient flat plate flow problem.