A Test of a Modular, Wall Adapted Nonlinear Filter Model for Underresolved Flows

A . Stabilization using filters is intended to model and extract the energy lost to resolved scales due to nonlinearity breaking down resolved scales to unresolved scales. This process is highly nonlinear. We consider nonlinear filters which select eddies for damping (simulating breakdown) based on knowledge of how nonlinearity acts in real flow problems. The particular form of the nonlinear filter allows for easy incorporation of more knowledge into the filter process and its computational complexity is comparable to calculating a linear filter of similar form. Herein we show how to adapt nonlinear filters to the near wall region, adapting an idea of Nicoud and Ducros, give a convergence result for the wall-adapted method and give a test which shows eddy viscosity can be highly localized and produce an excellent result.