Experiments concerned with the measurement of viscous resistance in rotating liquid helium II have been analyzed on the basis of the stratification model for the superfluid motion. The onset of nonlinear dissipation is attributed to the setting in of large-scale vorticity in the superfluid and it is proposed that this would happen at a certain "critical" velocity corresponding to which the thickness of the layers becomes of the order of the "correlation length." The magnitude of this characteristic length turns out to be about 8×${10}^{-5\mathrm{}}$ cm. Further, the concept of stratified motion has also been applied to linear flow through the supersurface film, leading thereby to a satisfactory explanation of the observations of Chandrasekhar and Mendelssohn.

• Received 16 October 1956

DOI:https://doi.org/10.1103/PhysRev.106.3