Torque on a Rayleigh Disk Due to He II Flow
The Rayleigh disk has been used in several experiments1–7 to probe the local velocity field of He II. However, the flow pattern around the disk has not been well understood.8 We present here a simple model for He II flow past a Rayleigh disk which assumes that superfluid potential flow and normal fluid Helmholtz flow occur. A torque which increases as the temperature decreases below T λ is predicted. New measurements of the torque on a Rayleigh disk in nonrotating helium are then presented which are in substantial agreement with this model. Finally, we show that our model is in agreement with Pellam’s Rayleigh disk measurements1–4 in rotating helium below T λ .
KeywordsPotential Flow Attack Angle Normal Fluid Superfluid Component Torque Increase
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- 2.J.R. Pellam, in Proc. 9th Intern. Conf. Low Temp. Phys., 1964, Plenum, New York (1965), p. 191.Google Scholar
- 5.D.S. Tsakadze and L.G. Shanshiashvilli, Zh. Eksperim, i Teor. Fiz. Pis’ma 2 305 (1965) [Soviet Phys.—JETP Lett. 2 194 (1965)].Google Scholar
- 6.J.R. Pellam, in Progress in Low Temperature Physics, C.J. Gorter, ed., North-Holland, Amsterdam (1955), Vol. 1, p. 54.Google Scholar