Van der Waals Cascade in Supercritical Turbulence near a Critical Point

TL;DR

This paper explores turbulence in supercritical fluids near a critical point, revealing a new van der Waals cascade at small scales influenced by density fluctuations, distinct from the classical Richardson cascade.

Contribution

It introduces the concept of a van der Waals cascade occurring at sub-correlation length scales in supercritical turbulence, expanding understanding of energy transfer mechanisms near critical points.

Findings

Identification of a crossover from Richardson to van der Waals cascade.

Conditions for observing the van der Waals cascade in experiments.

Analysis of turbulence behavior at scales smaller than the correlation length.

Abstract

We investigate a quite strong turbulence in a supercritical fluid near a gas-liquid critical point. Specifically, we consider a case in which the Kolmogorov scale is much smaller than the equilibrium correlation length $\xi$. Although equilibrium critical fluctuations are destroyed by turbulence, $\xi$ still provides a crossover length scale between two types of energy cascade. At scales much larger than $\xi$, the Richardson cascade becomes dominant, whereas at scales much smaller than $\xi$, another type of cascade, which we call the van der Waals cascade, is induced by density fluctuations. Experimental conditions required to observe the van der Waals cascade are also discussed.