Cumulative distribution of the stretching of vortical structures in isotropic turbulence

Abstract

By using a Navier-Stokes isotropic turbulent field numerically simulated in the box with a discretization of 10243 [Biferale et al. (2005)], we show that the probability of having a stretching-tilting larger than twice the local enstrophy is very small. This probability decreases if we try to filter out the large scales, while it increases filtering out the small scales. This is basically due to the suppression of the compact structures (blobs).