Hybrid grid-free and grid-based method for simulation of turbulent flows

Abstract

The principles of a new vortex particle intensified large eddy simulation (VπLES) method based on grid-based/grid-free techniques are described. The method is based on the idea of dividing the flow into large-scale and small-scale motions, with the first being solved on a grid, and the second using the vortex particle method. This article provides a brief overview of previous validation and verification results and further illustrates the advantages of VπLES for passive mixing in homogeneous decaying isotropic turbulence and free jet. VπLES, which is a kind of reduced-order model with a direct reconstruction of the subgrid motion by vortex particles, was used to study the anisotropy of small-scale motion in a free jet. The application of VπLES to the flow in the channel makes it possible to restore the high-frequency part of the spectrum with relatively coarse resolution due to explicit modeling of small-scale vortices.