Constrained large-eddy simulation of wall-bounded compressible turbulent flows

Abstract

A constrained large-eddy simulation (CLES) approach is developed for wall-bounded compressible turbulent flows based on its incompressible analogue [Chen et al., “Reynolds-stress-constrained large-eddy simulation of wall-bounded turbulent flows,” J. Fluid Mech. 703, 1–28 (2012)]. In the new CLES approach, both the subgrid-scale (SGS) stress and the SGS heat flux are decomposed into an averaged part and a fluctuating part in the near-wall region with the mean SGS stress and heat flux constrained by prescribed Reynolds stress model and turbulent heat flux model, respectively. The Smagorinsky SGS models are employed to approximate the SGS stress and heat flux in the remaining region of the flow domain. The present CLES method is validated by simulating the compressible turbulent channel flows at various Reynolds numbers and Mach numbers. The mean velocity profiles, mean temperature profiles, and other statistical quantities and turbulent structures are obtained and well compared among the present approach, direct numerical simulation (DNS), detached eddy simulation (DES) and traditional large eddy simulation (LES). The results demonstrate that the dual constraint of Reynolds stress and turbulent heat flux plays a non-trivial role in enhancing the ability of LES for wall-bounded compressible flows. In addition, the Reynolds and Mach numbers effects on the mean and statistical quantities as well as the turbulence structures are investigated using the proposed CLES method. The main conclusions are in very good agreement with those drawn by other authors using DNS method. All the results manifest that the present CLES technique is an encouraging and useful tool for wall-bounded compressible turbulent flows.