Grid resolution requirement for resolving rare and high intensity wall-shear stress events in direct numerical simulations

Abstract

Wall-shear stress becomes more intermittent as the Reynolds number (Re) of a flow increases. To properly resolve wall shear stress events in direct numerical simulations thus requires finer grids at higher Re. In this work we examine the grid resolution required to resolve a given percentage of wall shear stress events as a function of Re. We find that the standard grid resolution does not capture a fraction of high intensity events which increases with Re and quantify the grid resolution needed to do so.