Distribution of Brownian particles in turbulence

TL;DR

This paper investigates how Brownian particles behave in turbulent flows, especially how diffusion influences their distribution and statistics, providing experimentally testable predictions.

Contribution

It extends previous work by including diffusion effects in the analysis of particle distribution in real turbulence without flow modeling.

Findings

Diffusion modifies particle distribution statistics.

Strange attractors are present in particle trajectories.

Predictions are experimentally testable.

Abstract

We consider Brownian particles immersed in the fluid which flow is turbulent. We study the limit where the particles' inertia is weak and their velocity relaxes fast to the velocity of the flow. The trajectories of the particles in this case have a strange attractor in the physical space, if the particles' diffusion is neglected. Under the latter condition the singular density of the particles was recently described completely. The analysis was done for real turbulence and did not involve the flow modeling. Here we take the diffusion into account showing how it modifies the statistics. The analysis is performed also for real turbulence. Experimentally testable predictions are made.