Characteristics of shearing motions in incompressible isotropic turbulence

Abstract

Shearing motions in isotropic turbulence are studied with a triple decomposition of velocity gradient tensor. A mean flow around the shearing motions exhibits a thin shear-layer pattern sustained by a biaxial strain. The thickness of each shear layer is well predicted by Burgers' vortex layer. Interplay between the shear and biaxial strain causes enstrophy production and strain self-amplification.