Vortex dynamics in rotating counterflow and plane Couette and Poiseuille turbulence in superfluid Helium

TL;DR

This paper generalizes an equation for vortex line density in superfluid helium turbulence to include velocity gradients and compares it with existing models and experimental data, enhancing understanding of vortex dynamics in various flow conditions.

Contribution

It introduces a generalized equation for vortex line density that accounts for velocity gradients and barycentric velocity, improving modeling accuracy in superfluid helium turbulence.

Findings

The generalized equation aligns well with experimental data.

It effectively describes vortex density in plane Couette and Poiseuille flows.

Comparison with Lipniacki's approach highlights improvements in modeling vortex dynamics.

Abstract

An equation previously proposed to describe the evolution of vortex line density in rotating counterflow turbulent tangles in superfluid helium is generalized to incorporate nonvanishing barycentric velocity and velocity gradients. Our generalization is compared with an analogous approach proposed by Lipniacki, and with experimental results by Swanson et al. in rotating counterflow, and it is used to evaluate the vortex density in plane Couette and Poiseuille flows of superfluid helium.