Large-Eddy Simulation of Turbulent Flows Using Implicit Subgrid-Scale Modeling

Abstract

In this paper we present large-eddy simulations of the turbulentflow in a channel with streamwise periodic constrictionsusingimplicitsubgrid-scale (SGS)modeling. Theemployed implicitsubgrid-scale model is thesocalled adaptive local deconvolution method (ALDM) recently proposed by Hickel & Adams. 1 In implicit SGS modeling numerical discretization and subgrid-scale modeling are merged together. Therefore, the explicit computation of the SGS stress tensor becomes unnecessary. ALDM is the first approach of providing a systematically framework for implicit SGS modeling in turbulent flows. Our computations are intended to compare the performance of the implicit model ALDM and the well-established Smagorinsky model with dynamic procedure on identically numerical grids. Results of computations performed at three different Reynolds numbers Re=10595, 5600 and 2808 are presented in in comparison to data provided by highly-resolved large-eddy simulation of Fr¨ 2 and Direct Numerical Simulation of Peller & Manhardt. 3 In the comparative tests it is shown that the implicit model performs at least as well as the explicit-subgrid scale model. Additionally, the realizability of the Reynolds stresses predicted by ALDM is verified by means of invariants of the anisotropy tensor. In the investigations we found that ALDM satisfies the realizability conditions of Lumley 4 without exception.