Spectral-dynamic model for large-eddy simulations of turbulent rotating channel flow

A new subgrid-scale model called the spectral-dynamic model is proposed. It consists of a refinement of spectral eddy-viscosity models taking into acc ount nondeveloped turbulence in the subgrid-scales. The proposed correction , which is derived from eddy-damped quasi-normal Markovian statistical theo ry, is based on an adjustment of the turbulent eddy-viscosity coefficient t o the deviation of the spectral slope (at small scales) with respect to the standard Kolmogorov law. The spectral-dynamic model is applied to large ed dy simulation (LES) of rotating and nonrotating turbulent plane channel flo ws. It is shown that the proposed refinement allows for clear improvement o f the statistical predictions due to a correct prediction of the near-wall behavior. Cases of rotating and nonrotating low (DNS) and high Reynolds (LE S) numbers are then compared. It is shown that the principal structural fea tures of the rotating turbulent channel flow are reproduced by the LES, suc h as the presence of the near-zero mean absolute vorticity region, the modi fication of the anisotropic character of the flow (with respect to the nonr otating case), the enhancement of how organization, and the inhibition of t he high- and low-speed streaks near the anticyclonic wall. Only a moderate Reynolds number dependence is exhibited, resulting in a more unstable chara cter of the longitudinal large-scale roll cells at high Reynolds number, an d a slight increase of the laminarization tendency on the cyclonic side of the channel.