Coherent Structure and Subgrid-Scale Energy Transfer in Turbulence

Abstract

Correlation of the transfer and dissipation of turbulent energy with the coherent structures is investigated. A classification method is developed to distinguish the tube and sheet structures. Two different kinds are considered for sheet structures. The grid-scale and subgrid-scale (SGS) energy exchange in large-eddy simulation (LES) is utilized to estimate the energy transfer. It is found that the cylindrical sheet region around the tube is organized, shielding the rather incoherent core region of tube. The energy transfer and dissipation were shown to take place primarily in the region similar to the Burgers’ vortex layer. The backward scatter primarily occurred along the compressed vortex tube. The role reversal of the vorticities along eigenvalues for the strain rate tensor is discussed.