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In the comment I develop a critical analysis of the use of the HVBK methodfor the study of three-dimensional turbulent flows of superfluids. Theconception of the vortex bundles forming the structure of quantum turbulence iscontroversial and does not justify the use of the HVBK method. In addition,this conception is counterproductive, because it gives incorrect ideas aboutthe structure of the vortex tangle as a set of bundles containing parallellines. The only type of dynamics of vortex filaments inside these bundles ispossible, namely, Kelvin waves running along the filaments. At the same time,as shown in numerous numerical simulations, a vortex tangle consists of a setof entangled vortex loops of different sizes and having a random walkstructure. These loops are subject to large deformations (due to highlynonlinear dynamics), they reconnect with each other and with the wall, splitand merge, creating a lot of daughter loops. They also bear Kelvin waves onthem, but the latter have little impact.  I also propose and discuss an alternative variant of study ofthree-dimensional turbulent flows, in which the vortex line density $\mathcal{L}(r,t)$ is not associated with $\nabla \times \mathbf{v}_{s}$, but itis an independent variable described by a separate equation.

Coarse-grained Hydrodynamics of turbulent superfluids: HVBK approach and the bundle structure of the vortex tangle