Large eddy simulation of rotating turbulent channel flow with a new dynamic global-coefficient nonlinear subgrid stress model

Abstract

In this paper, a new dynamic global-coefficient nonlinear subgrid scale (SGS) model is proposed for large eddy simulation (LES) of rotating turbulent channel flow. The basic model is a nonlinear model with a tensorial polynomial relation between the SGS stress and the resolved strain rate tensor. A new dynamic procedure is proposed to determine the model coefficients of the nonlinear model. The new dynamic method is derived from the globally averaged transport equation of the Reynolds shear stress, on which the rotation has strong and direct effects. The new dynamic nonlinear SGS model is examined in rotating turbulent channel at Re=umh/ν=7000, Ro=2Ωh/um =0.3 and 0.6, where Reynolds number Re and Rotation number Ro are defined by bulk mean velocity um , half channel width h, kinematic viscosity ν and angular velocity of spanwise rotation Ω. The statistical results obtained from the new model agree well with those from direct numerical simulation (DNS). The new model also successfully predicts the major structures in rotating turbulent channel flow, such as Taylor–Görtler vortices and streaks.