Grid-independent large-eddy simulation of turbulent wake flow using explicit differential filters

Abstract

Large-eddy simulations (LES) using explicit filtering are performed to obtain grid-independent solutions of turbulent wake flow behind a circular cylinder at ReD = 3900 on non-Cartesian type grids. A differential elliptic equation where the filter kernel is implicitly defined is discretized in an unstructured-grid solver to enable explicit filtering on non-Cartesian grids. The separation of filtering procedure from discretization is known to produce an LES solution of which error is mainly attributed to the capability of a sub-filter scale (SFS) model. Equipped with the differential filter and the Vreman SFS model, explicitly filtered LES on unstructured grids is shown to produce nearly grid-independent solutions for flow over a circular cylinder at a critical Reynolds number.