Dynamics of turbulent plugs in a superfluid He channel counterflow
arXiv:2002.05002 · doi:10.1103/PhysRevB.101.134515
Abstract
Quantum turbulence in superfluid He-4 in narrow channels often takes the form of moving localized vortex tangles. Such tangles, called turbulent plugs, also serve as building blocks of quantum turbulence in wider channels. We report on a numerical study of various aspects of the dynamics and structure of turbulent plugs in a wide range of governing parameters. The unrestricted growth of the tangle in a long channel provides a unique view on a natural tangle structure including superfluid motion at many scales. We argue that the edges of the plugs propagate as turbulent fronts, following the advection-diffusion-reaction dynamics. This analysis shows that the dynamics of the two edges of the tangle have distinctly different nature. We provide an analytic solution of the equation of motion for the fronts that define their shape, velocities and effective diffusivity, and analyze these parameters for various flow conditions.
25 pages, 26 figures
References in corpus (12)
- An exploration of thermal counterflow in He II using particle tracking velocimetry
- Three-Dimensional Coupled Dynamics of Two-Fluid Model in Superfluid He: Deformed Velocity Profile of Normal Fluid in Thermal Counterflow
- Dynamics of the Density of Quantized Vortex-Lines in Superfluid Turbulence
- Counterflow quantum turbulence of He II in a square channel: Numerical analysis with nonuniform flows of the normal fluid
- Dissipation in quantum turbulence in superfluid He above 1K
- On the Nonuniform Quantum Turbulence in Superfluids
- Transition to turbulence and streamwise inhomogeneity of vortex tangle in thermal counterflow
- Coupled dynamics for superfluid He in the channel
- Diffusion of Quantum Vortices
- Inviscid diffusion of vorticity in low temperature superfluid helium
- Reply to Comment on "Dynamics of the Density of Quantized Vortex-Lines in Superfluid Turbulence"
- Dynamics of the vortex line density in superfluid counterflow turbulence