Inhomogeneous distribution of particles in co-flow and counterflow quantum turbulence

TL;DR

This study investigates how particles distribute in superfluid helium turbulence, revealing temperature-dependent clustering behaviors and flow dimensionality effects through numerical simulations.

Contribution

It introduces a detailed numerical analysis of particle dynamics in superfluid turbulence considering both fluid components and temperature effects.

Findings

Particles cluster in vortex filaments at low temperatures.

Clustering behavior approaches classical turbulence in coflow at higher temperatures.

Counterflow induces quasi-two-dimensional particle distributions.

Abstract

Particles are today the main tool to study superfluid turbulence and visualize quantum vortices. In this work, we study the dynamics and the spatial distribution of particles in co-flow and counterflow superfluid helium turbulence in the framework of the two-fluid Hall-Vinen-Bekarevich-Khalatnikov (HVBK) model. We perform three-dimensional numerical simulations of the HVBK equations along with the particle dynamics that depends on the motion of both fluid components. We find that, at low temperatures, where the superfluid mass fraction dominates, particles strongly cluster in vortex filaments regardless of their physical properties. At higher temperatures, as viscous drag becomes important and the two components become tightly coupled, the clustering dynamics in the coflowing case approach those found in classical turbulence, while under strong counterflow, the particle distribution is dominated by the quasi-two-dimensionalization of the flow.