Large eddy simulations of turbulent channel flow based on interscale energy transfer

TL;DR

This paper extends a modeling procedure for large eddy simulations to inhomogeneous flows, combining structural and functional strategies to accurately recover subgrid scale dissipation and improve numerical robustness across various conditions.

Contribution

It introduces a general, self-contained method that accurately models subgrid scale dissipation in LES of inhomogeneous turbulence, inspired by homogeneous turbulence analyses.

Findings

Capable of providing proper total energy dissipation in low-resolution LES.

Works well across different filtering kernels, Reynolds numbers, and grid resolutions.

Enhances numerical robustness through automatic backscatter control.

Abstract

A previously developed modeling procedure for large eddy simulations (LESs) is extended to allow physical space implementations for inhomogeneous flows. The method is inspired by the well-established theoretical analyses and numerical investigations of homogeneous, isotropic turbulence. A general procedure that focuses on recovering the full subgrid scale (SGS) dissipation from resolved fields is formulated, combining the advantages of both the structural and the functional strategy of modeling. The interscale energy transfer is obtained from the test-filtered velocity field, corresponding subfilter scale (SFS) stress or, equivalently, the similarity model is used to compute the total SGS dissipation. The energy transfer is then cast in the form of eddy viscosity, allowing it to retain the desired total SGS dissipation and making the method numerically robust as an automatic step of backscatter control. The method is capable of providing a proper amount of total energy dissipation in actual, low resolution LES runs. The new approach is general and self-contained, working well for different filtering kernels, Reynolds numbers, and grid resolutions.