The dynamics of vorticity tubes in homogeneous turbulence

Abstract

Analysis of data from a direct simulation of statistically steady homogeneous turbulence suggests that the vorticity tubes, which constitute the main structure of the vorticity field, are produced by shear instabilities. This is confirmed by a decay calculation, in which vorticity sheets appear at first, and then roll up to form the first tubes. These instabilities seem to be at least as important as vortex stretching in transferring energy from large to small scales.