Extra-Large Eddy Simulation of Massively Separated Flows

Abstract

A new hybrid method between Reynolds-Averaged Navier‐Stokes (RANS) and Large Eddy Simulation (LES) is presented. The method, named eXtra-Large Eddy Simulation (X-LES), consists of a composite formulation incorporating both RANS and LES equations. The time-dependent RANS‐LES boundary is governed implicitly by this composite formulation. The composite formulation has two clear advantages over other, comparable hybrid RANS‐LES approaches: it uses a clearly defined subgrid-scale (SGS) model in LES mode and it does not depend on the wall distance.