Variational Multiscale Large Eddy Simulation of Turbulent Flows Using a Two-Grid Finite Element or Finite Volume Method

Abstract

Abstract In this article, variational multiscale large eddy simulation based on multigrid scale-separating operators is presented. Two different scale-separating operators, which are basically applicable within both a finite element and a finite volume method, are proposed for separating large resolved scales and small resolved scales. One of these operators is a projector. Using the multigrid operators for scale separation, dynamic and non-dynamic subgrid-scale modeling approaches are applied to the challenging test case of turbulent flow in a diffuser. Variational multiscale large eddy simulation using a projective multigrid scale-separating operator provides remarkable results already in combination with a simple non-dynamic subgrid-scale modeling approach. Furthermore, this methodical combination turns out to be very efficient with regard to the important aspect of computational cost.