Quantum turbulence accompanying thermal counterflow in superfluid 4 He was recently visualized by the Maryland group, using micron-sized tracer particles of solid hydrogen (J. Phys. Soc. Jpn. 77, 111007 (2008)) . In order to understand the observations we formulate the coupled dynamics of fine particles and quantized vortices, in the presence of a relative motion of the normal and superfluid components. Numerical simulations based on this formulation are shown to agree reasonably well with experimental observations of the velocity distributions of the tracer particles in thermal counterflow.
We have simulated the decay of thermal counterflow quantum turbulence from a statistically steady state at T =1.9 [K], with the assumption that the normal fluid is at rest during the decay. The results are consistent with the predictions of the Vinen equation (in essence the vortex line density (VLD) decays as t −1 ). For the statistically steady state, we determine the parameter c 2 , which connects the curvature of the vortex lines and the mean separation of vortices. A formula connecting the parameter χ 2 of the Vinen equation with c 2 is shown to agree with the results of the simulations. Disagreement with experiment is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.