Large-scale turbulent flow around a cylinder in counterflow superfluid4He (He (II))

Abstract

The detailed nature of fluid flow over a cylinder is one of the fundamental topics in classical fluid dynamics as it demonstrates flow separation and vortex shedding1. In superfluid helium, either He (II) or the B phase of3He, an important question has been to what extent these quantum fluids show classical fluid turbulent states2,3,4. Although the existence of turbulent structures can be inferred using precise instrumentation5,6, direct visualization of the flow field can provide unequivocal evidence of these phenomena. Here we show the existence of large turbulent structures in He (II) counterflow across a cylinder as obtained by the particle image velocimetry technique. Compared with classical fluid flow, the particle motion driven by He (II) counterflow shows macroscopic eddies downstream of the cylinder but also similar structures are observed in front of the cylinder, behaviour not seen in classical fluids. As Landau’s two-fluid model7 for He (II) describes counterflow as the relative motion of the superfluid and normal fluid components, the current results indicate that both components may be undergoing a kind of flow separation as they pass over the cylinder.

Cite this article

Zhang, T., Van Sciver, S. Large-scale turbulent flow around a cylinder in counterflow superfluid⁴He (He (II)). Nature Phys 1, 36–38 (2005). https://doi.org/10.1038/nphys114

View full text

>> Full Text:   Large-scale turbulent flow around a cylinder in counterflow superfluid4He (He (II))