Dusty turbulence

TL;DR

This paper reveals a new scaling law for velocity fluctuations in dusty turbulence, driven by particle-induced Kelvin-Helmholtz instabilities, confirmed through numerical simulations.

Contribution

It introduces a novel scaling law for velocity spectra in dusty turbulence resulting from particle feedback forces.

Findings

Velocity spectra follow a $k^{-2}$ power law.

Kelvin-Helmholtz instabilities facilitate energy transfer to small scales.

Numerical simulations confirm the proposed mechanism.

Abstract

The feedback forces exerted by particles suspended in a turbulent flow is shown to lead to a new scaling law for velocity fluctuations associated to a power-spectra $\propto k^{-2}$. The mechanism at play relies on a direct transfer of kinetic energy to small scales through Kelvin--Helmholtz instabilities occurring in regions of high particle density contrast. This finding is confirmed by two-dimensional direct numerical simulations.