Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Particle Dynamics in 4He Flows Due to Oscillating Grids
P. Švančara, M. La Mantia
Abstract:
We investigate cryogenic flows of liquid ⁴He between two grids oscillating in phase, at temperatures ranging from about 1:3 to 2.5 K, by following the motions of small particles suspended in the fluid. We focus on flows of superfluid ⁴He, which are known to display, in certain conditions, features different from those observed in flows of classical viscous fluids, such as water. We find that, at large enough flow scales, the shapes of the velocity and velocity increment statistical distributions are very similar to those obtained in turbulent flows of viscous fluids. The outcome reinforces the idea that, above 1 K and at large enough length scales, particles probing flows of superuid ⁴He behave as they were tracking classical flows, regardless of the mechanism of flow generation.
Keywords:
superfluidity, flow visualization, oscillatory flows

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2017.037

In Proceedings Topical Problems of Fluid Mechanics 2017, Prague, 2017 Edited by David Šimurda and Tomáš Bodnár, pp. 295-302 ISBN 978-80-87012-61-1 (Print) ISSN 2336-5781 (Print)