Velocity distributions of tracer particles in thermal counterflow in superfluid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow /><mml:mn>4</mml:mn></mml:msup></mml:math>He

Mineda, Yoshikazu; Tsubota, Makoto; Sergeev, Yu. A.; Barenghi, Carlo F.; Vinen, W. F.

doi:10.1103/physrevb.87.174508

Cited by 21 publications

(24 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should also be kept in mind that while fluctuations of the local vortex line velocity play a large role in G1 velocity fluctuations [18], they are not solely responsible. Other factors, such as drag from the normal fluid, can also affect the G1 particle velocity [7,8]. Nonetheless, the results indicate that use of PTV to estimate c 2 is indeed feasible, implying that the parameter can be spatially resolved by estimating its local value based on local G1 velocity fluctuations.…”

Section: Experimental Measurement Of Cmentioning

confidence: 94%

Characterizing vortex tangle properties in steady-state He II counterflow using particle tracking velocimetry

Mastracci

Guo

2019

Phys. Rev. Fluids

View full text Add to dashboard Cite

Historically, there is little faith in particle tracking velocimetry (PTV) as a tool to make quantitative measurements of thermal counterflow in He II, since tracer particle motion is complicated by influences from the normal fluid, superfluid, and quantized vortex lines, or a combination thereof.Recently, we introduced a scheme for differentiating particles trapped on vortices (G1) from particles entrained by the normal fluid (G2). In this paper, we apply this scheme to demonstrate the utility of PTV for quantitative measurements of vortex dynamics in He II counterflow. We estimate ℓ, the mean vortex line spacing, using G2 velocity data, and c 2 , a parameter related to the mean curvature radius of vortices and energy dissipation in quantum turbulence, using G1 velocity data. We find that both estimations show good agreement with existing measurements that were obtained using traditional experimental methods. This is of particular consequence since these parameters likely vary in space, and PTV offers the advantage of spatial resolution. We also show a direct link between power-law tails in transverse particle velocity probability density functions (PDFs) and reconnection of vortex lines on which G1 particles are trapped.

show abstract

Section: Experimental Measurement Of Cmentioning

confidence: 94%

Characterizing vortex tangle properties in steady-state He II counterflow using particle tracking velocimetry

Mastracci

Guo

2019

Phys. Rev. Fluids

View full text Add to dashboard Cite

show abstract

“…To this end, we perform a series of numerical experiments, extending the work of Mineda et al [14], which simulates the movement of seeding particles in the velocity field due to the counterflow tangle of quantized vortices. We find that a trapped particle deforms the vortex on which it is trapped, stretching it in the direction of the flowing normal fluid, via the action of the Stokes drag.…”

Section: Introductionmentioning

confidence: 99%

Backreaction of Tracer Particles on Vortex Tangle in Helium II Counterflow

et al. 2015

View full text Add to dashboard Cite

We report computer simulations of the interaction of seeding particles with quantized vortices and with the normal fluid flow in thermal counterflow of superfluid 4 He. We show that if the particle concentration is too large, the vortex tangle is significantly affected, posing problems in the interpretation of visualization experiments. The main effects are an increase in vortex line density and a change in polarization of the vortex tangle, caused by the action of the Stokes drag of the viscous normal fluid on the trapped particles. We argue that in the case of large particle concentration, typically used for the particle image velocimetry technique, the tangle properties might become significantly changed. On the contrary, the particle tracking velocimetry technique that uses smaller particle concentration should not be appreciably affected.

show abstract

“…In order to take account for the particle-vortex interaction, we introduce the equation of motion for a trapped particle as described in Ref. [13]. By making three assumptions, we are able to let a vortex point represent the trapped particle.…”

Section: Methodsmentioning

confidence: 99%

Dynamics of fine particles due to quantized vortices on the surface of superfluid $^4$He

Inui,

Tsubota,

Moroshkin

et al. 2018

Preprint

View full text Add to dashboard Cite

We have conducted calculations of the coupled dynamics of quantized vortices and fine metallic particles trapped at a free surface of superfluid 4 He. The computational result so far indicates that a particle-vortex complex may produce quasi-periodic motions along the surface and that the motions can be enhanced if the metallic particles are heated and induce local radial flows. Our results qualitatively reproduce recent experimental observations of trapped particle motion. Keywords quantized vortices • free surface of 4 He 1 IntroductionA new dynamical aspect of superfluid 4 He that involves both bulk quantized vortices and the free surface of the system may have been revealed by the experiment utilizing a number of electrically charged fine metallic particles

show abstract

Velocity distributions of tracer particles in thermal counterflow in superfluid4He

Cited by 21 publications

References 19 publications

Characterizing vortex tangle properties in steady-state He II counterflow using particle tracking velocimetry

Characterizing vortex tangle properties in steady-state He II counterflow using particle tracking velocimetry

Backreaction of Tracer Particles on Vortex Tangle in Helium II Counterflow

Dynamics of fine particles due to quantized vortices on the surface of superfluid $^4$He

Contact Info

Product

Resources

About