Reynolds number dependency of small scale structures in steady anisotropic turbulence produced by implicit large-eddy simulation

This study presents small-scale fluctuation characteristics of anisotropic steady turbulence reproduced by implicit large eddy simulation (LES). The Reynolds number dependence of this small-scale fluctuation characteristic is approached in this study. This study focuses on that, a small scale turbulence field is not needed to be isotropic if the Reynolds number is sufficiently high. The anisotropic steady turbulence is maintained steady by using the forcing terms in the governing equations. The results of the implicit LES are compared with those obtained by direct numerical simulation (DNS) and LES based on the Smagorinsky model. Spatial derivatives are discretized using a fourth-order central difference scheme that conserves the kinetic energy of the turbulence field. The governing equations are integrated for the temporal direction using the fourth-order Runge-Kutta method. The results of enstrophy and small-scale turbulence characteristics quantified by the isotropy parameter are found to be consistent between the implicit LES and DNS.