Search results for " Vortex diffusion"

showing 3 items of 3 documents

HEAT FLUX IN SUPERFLUID TRANSITION AND IN TURBULENT HELIUM COUNTERFLOW

Normal fluid profileRadial flow Vortex diffusionTwo-fluid modelHelium 4Ballistic regimeInhomogeneous vortex tangles.lambda TransitionHeat transferQuantized vorticeEffective thermal conductivityTurbulent superfluid helium ( He II)One-fluid modelExtended Irreversible ThermodynamicEntrance regionSettore MAT/07 - Fisica MatematicaLongitudinal flow
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Thermodynamic approach to vortex production and diffusion in inhomogeneous superfluid turbulence

2014

In this paper, we use a non-equilibrium thermodynamic framework to generalize a previous nonlocal model of counterflow superfluid turbulence to incorporate some new coupled terms which may be relevant in the evolution of inhomogeneous vortex tangles. The theory chooses as fundamental fields the energy density, the heat flux, and the averaged vortex line length per unit volume. The constitutive quantities are assumed to depend on the fundamental fields and on their first spatial derivatives, allowing us to describe thermal dissipation, vortex diffusion and a new contribution to vortex formation. The restrictions on the constitutive relations are deduced from the entropy principle, using the …

Statistics and ProbabilityPhysicsTurbulenceQuantum turbulenceCondensed Matter PhysicsQuantum turbulence quantized vortices heat transfer inhomogeneous vortex tangle vortex diffusion entropy fluxVortexSuperfluidityEntropy (classical thermodynamics)symbols.namesakeClassical mechanicsHeat fluxLagrange multiplierHeat transfersymbolsSettore MAT/07 - Fisica Matematica
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Inhomogeneous vortex tangles in counterflow superfluid turbulence: flow in convergent channels

2016

Abstract We investigate the evolution equation for the average vortex length per unit volume L of superfluid turbulence in inhomogeneous flows. Inhomogeneities in line density L andincounterflowvelocity V may contribute to vortex diffusion, vortex formation and vortex destruction. We explore two different families of contributions: those arising from asecondorder expansionofthe Vinenequationitself, andthose whichare notrelated to the original Vinen equation but must be stated by adding to it second-order terms obtained from dimensional analysis or other physical arguments.

T57-57.97Applied mathematics. Quantitative methodsTurbulenceApplied MathematicsQuantum turbulenceQuantum turbulence quantized vortices heat transfer inhomogeneous vortex tangle vortex diffusion.Quantized vorticesquantum turbulencevortex diffusion01 natural sciencesIndustrial and Manufacturing Engineering010305 fluids & plasmasVortexSuperfluidityClassical mechanicsCondensed Matter::Superconductivity0103 physical sciencesHeat transferheat transferinhomogeneous vortex tangle010306 general physicsSettore MAT/07 - Fisica Matematicaquantized vorticesCommunications in Applied and Industrial Mathematics
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