Abstract
We investigate cryogenic flows of liquid He-4 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 He-4, 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 superfluid He-4 behave as they were tracking classical flows, regardless of the mechanism of flow generation.