Comment on "On the relations between large-scale models of superfluid helium-4" [Phys. Fluids 33, 127124 (2021]"

TL;DR

This paper critiques the use of the HVBK model and vortex bundle approach in describing three-dimensional quantum turbulence in superfluid helium-4, highlighting significant disagreements with prior formalism.

Contribution

It provides a critical analysis of the HVBK model and vortex bundle assumptions in the context of quantum turbulence, challenging their applicability.

Findings

Disagrees with HVBK model for 3D quantum turbulence

Critiques vortex bundle model as a basis for HVBK

Highlights limitations of coarse-grained flow descriptions

Abstract

We comment on the paper by M. S\'ykora, M. Pavelka, M. La Mantia, D. Jou, and M. Grmela "On the relations between large-scale models of superfluid helium-4," Physics of Fluids, 33(12):127124(2021), where the authors have developed a formalism for describing a coarse-grained flow of superfluid helium. This formalism is greatly based on the Hall-Vinen-Bekarevich-Khalatnikov (HVBK) model. We strongly disagree with the use of the HVBK equation approach for the case of the three-dimensional quantum turbulence and expose our objections in this comment. We discuss the HVBK method and also criticize the so-called vortex bundles model, which serves as a basis for using the HVBK method in a three-dimensional quantum turbulence.