Evidence for multiplicative cascades as the origin of small-scale intermittency in turbulence

TL;DR

This paper provides evidence that small-scale turbulence intermittency originates from a local multiplicative cascade process, linking intense event dynamics to the energy cascade through analysis of numerical simulations.

Contribution

It demonstrates the connection between intense turbulence events and multiplicative cascades using generalized means in direct numerical simulations.

Findings

Intense turbulence events are modulated by large-scale fluctuations.

Evolution of these events aligns with a local multiplicative cascade model.

Supports the hypothesis of cascade-driven small-scale intermittency.

Abstract

This investigation presents evidence of the relation between the dynamics of intense events in small-scale turbulence and the energy cascade. We use the generalised (H\"older) means to track the temporal evolution of intense events of the enstrophy and the dissipation in direct numerical simulations of isotropic turbulence. We show that these events are modulated by large-scale fluctuations, and that their evolution is consistent with a local multiplicative cascade, as hypothesised by a broad class of intermittency models of turbulence.