Superfluids flex their muscles: wakes, storms and turbulence If vortices
If vortices are the “sinews and muscles of fluid motions” in everyday viscous fluids (Kuchemann, 1965) then in superfluids they are the bones too. Superfluid vortices are constrained by quantum mechanics to have fixed width and strength, such that any significant agitation of the fluid has a skeleton of these vortex lines. This property, along with the absence of viscosity, means that superfluids embody an idealised prototype fluid.
Given these special properties, how does a superfluid flow, does its behaviour mirror that of everyday viscous fluids, and are there truly quantum behaviours? I will explain how recent discoveries in superfluid helium and superfluid atomic gases, from vortex streets and reconnections to boundary layers and turbulence, are providing insight into these questions, and pointing to a deep connection between quantum and classical flow. Finally, I will discuss how ultracold gases of dipolar atoms open the door to study novel ferrofluidic forms of turbulence.
Dr Nick Parker, University of Newcastle