Sergey K. Nemirovskii

Comment on “Dynamics of the density of quantized vortex lines in superfluid turbulence”

In the paper by Khomenko et al. [Phys. Rev. B 91, 180504 (2015)] the authors, numerically analyzing the steady counterflowing helium in an inhomogeneous channel flow, concluded that the production term

Dynamics of Quantized Vortices Before Reconnection

\mathcal{P}

Torsional oscillation of vortex tangles. Possible applications to oscillations of solid 4He

in the Vinen equation is proportional to

Numerical simulation of stochastic motion of vortex loops under action of random force. Evidence of the thermodynamic equilibrium state

|{\mathbf{V}}_{\mathrm{ns}}{|}^{3}{\mathcal{L}}^{1/2}

Quantum turbulence: Theoretical and numerical problems

(where

Diffusion of inhomogeneous vortex tangle and decay of superfluid turbulence

\mathcal{L}

GAUSSIAN MODEL OF VORTEX TANGLE IN HE II

is the vortex-line density and

Kinetics of a network of vortex Loops in He II and a theory of superfluid turbulence

{\mathbf{V}}_{\mathrm{ns}}

Langevin Dynamics of Vortex Lines and Thermodynamic Equilibrium of Vortex Tangle

is the counterflow velocity). In this Comment we demonstrated that the procedure, implemented by the authors, includes a number of questionable steps, such as a decomposition of velocity of line and interpretation of the flux term. Additionally, the overall strategy,\char22{}extracting information on the temporal behavior from the stationary solution also remains questionable. Because the method of determination of the explicit shape of the Vinen equation is very sensitive to the listed elements, the final conclusion of the authors cannot be considered as unambiguous.

SUPERFLUID MASS CURRENT INDUCED BY CHAOTIC VORTEX LINES IN TURBULENT HE II

The main goal of this paper is to investigate numerically the dynamics of quantized vortex loops, just before the reconnection at finite temperature, when mutual friction essentially changes the evolution of lines. Modeling is performed on the base of vortex filament method using the full Biot–Savart equation. It was discovered that the initial position of vortices and the temperature strongly affect the dependence on time of the minimum distance