Reconnection dynamics and mutual friction in quantum turbulence

TL;DR

This paper studies how vortex reconnections influence mutual friction in quantum turbulence of superfluid helium, highlighting reconnections as key in generating high-curvature regions affecting turbulence dynamics.

Contribution

It demonstrates the role of vortex reconnections in mutual friction and provides statistical analysis of vortex tangles using the vortex filament model.

Findings

Reconnections are primary in creating high-curvature, high-velocity regions.

Mutual friction correlates strongly with reconnection events.

Different vortex tangle types exhibit distinct mutual friction behaviors.

Abstract

We investigate the behaviour of the mutual friction force in finite temperature quantum turbulence in $^4$He, paying particular attention to the role of quantized vortex reconnections. Through the use of the vortex filament model, we produce three experimentally relevant types of vortex tangles in steady-state conditions, and examine through statistical analysis, how local properties of the tangle influence the mutual friction force. Finally, by monitoring reconnection events, we present evidence to indicate that vortex reconnections are the dominant mechanism for producing areas of high curvature and velocity leading to regions of high mutual friction, particularly for homogeneous and isotropic vortex tangles.