Newtonian-like behavior of starting vortex flow in superfluid helium at high Reynolds numbers

TL;DR

This study demonstrates that superfluid helium-4 exhibits vortex behavior similar to classical Newtonian fluids at high Reynolds numbers, suggesting its potential as a model for classical fluid dynamics in turbulent flow regimes.

Contribution

It provides experimental evidence that superfluid helium-4 can mimic classical Newtonian vortex dynamics at high Reynolds numbers, expanding its use in fluid mechanics research.

Findings

Vortex positions in superfluid helium match classical predictions at high Reynolds numbers.

Superfluid helium-4 exhibits Newtonian-like vortex behavior when thermal effects are negligible.

Turbulent flows in superfluid helium can be analogous to classical Newtonian flows.

Abstract

We study experimentally the starting vortices shed by airfoils accelerating uniformly from rest in superfluid helium-4 (He II). The vortices behave apparently as if they were moving in a classical Newtonian fluid, such as air or water. Specifically, the starting vortex positions obtained from the experimental data are found to be very close to those computed numerically in a Newtonian fluid, at sufficiently small times, when self-similar behavior is expected to occur, and for Reynolds numbers ranging approximately between $5 \times 10^2$ and $5 \times 10^5$. The result indicates neatly that turbulent flows of He II can be very similar to classical flows of Newtonian fluids, when thermal effects can be neglected and at sufficiently large flow scales, i.e. the study demonstrates that superfluid helium-4 could also be employed to study classical Newtonian flows.