A dynamic wall model for large eddy simulation of turbulent flow over complex/moving boundaries based on the immersed boundary method

Abstract

A hybrid immersed boundary/wall-model approach for large eddy simulation is developed for turbulent flows with complex/moving boundaries. The filtered Navier-Stokes equations are solved on a regular Eulerian mesh, with the no-slip condition on the wall imposed through the continuous forcing of the immersed boundary (IB) method. To implement the wall model, the thin boundary layer equation is solved on an embedded mesh refined along the wall-normal direction and a dynamic matching procedure is adopted. Near-wall subgrid-scale viscosity is further modified by taking into account the influence of IB forcing. The proposed method is tested on several numerical examples, including turbulent channel flow, turbulent flow over periodic hills, and turbulent channel flow with a traveling wavy wall. The mean velocity profile and turbulent fluctuations are reasonably well predicted in the canonical channel flow, as well as in flows with a complex/moving boundary and large flow separation.