Liquid helium films. II. The flow of the film

Abstract

The rate of flow of the helium II film has been found to vary slightly with the height of the film and the pressure head. Most of the variation can be ascribed to changes in the thickness of the film, but a small residual variation at small pressure heads suggests that at least part of the flow is subject to frictional retardation. Measurements of the damping of the film oscillations enable a small upper limit to be put on the frictional retardation of the remaining part, but a similar method applied to flow through wide capillaries indicates that in this case most of the flow is opposed by frictional forces. The results are discussed in conjunction with the measurements of Allen & Misener on flow through capillaries and an attempt made to formulate some of the general features of the flow of the superfluid component.