Rotating Couette Flow of Superfluid Helium
Equations for the flow of He II when ∇ × υ s ≠ 0 have been proposed but have not been tested thoroughly. Here I refer to the derivations by Hall and Vinen and by Bekeravich and Khalatnikov (HVBK). There are seven terms in these equations which do not appear in the Landau-Khalatnikov equations; they may be attributed to vorticity in the superfluid. Many experiments have been described in the literature which test two or three of the vorticity terms in the HVBK equations. In these tests the experimental arrangement is chosen to make the magnitude of a particular vorticity term much larger than the others, and it is assumed that the term being tested is the only contributor to the result. Notable are the torsion-pendulum studies of Hall and the rotating second-sound attenuation measurements of Hall and Vinen. All the vorticity terms have not been tested and no experiments have been reported in which each of the seven terms contributes appreciably to the result.
KeywordsVortex Attenuation Helium Vorticity Librium
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