High-order gas-kinetic scheme for large eddy simulation of turbulent channel flows

Abstract

In this study, the high-order gas kinetic scheme (GKS) is employed for explicit large eddy simulation (hereafter referred to simply as “LES”) and implicit large eddy simulation (iLES) of turbulent channel flows. The main objective is to compare the performance of iLES and LES in the high-order finite volume framework, and study which is most suitable for turbulence simulation. The prediction abilities of different explicit LES models and iLES method on various statistics and flow structures are compared. Most results from both iLES and explicit LES are very close to those of direct numerical simulation. Moreover, iLES is generally superior to explicit LES in predicting several important flow properties, including the mean velocity profiles, Reynolds stress, and Q-criterion iso-surfaces. This superior performance of iLES may arise that the numerical dissipation of the high-order scheme is enough to replace the subgrid dissipation needed in large eddy simulation of turbulence. If the explicit LES model is further adopted, the dissipation will increase, so the results degrade. The overall satisfactory results show that the high-order GKS can provide appropriate numerical dissipation and is suitable for iLES of turbulence.