Superfluid Flow: Macroscopic Limit

From an experimental investigation of superfluid film transfer in narrow beakers in helium II it emerges that there are probably two kinds of film. A ‘normal’ film is formed by superfluid creep over a dry substrate. A ‘thick’ film remains when liquid has drained from a substrate that has previously been immersed in the liquid helium bath. A comparison has been made of the superfluid flow between the two types of film. Scatter of values of transfer rate associated with a normal film is attributed to third sound generated by bath waves impinging on the meniscus at the base of the film. The thick film shows an enhanced rate of transfer which can persist for long periods of time in quiet conditions, but which can be abruptly diminished by disturbances such as bath surface agitation. There is a maximum stable length for a thick film exhibiting the full enhanced rate. The enhanced rate can be as much as 60% greater than the normal rate at 1° K, but the difference between the two rates of transfer disappears above 1.8 °K. No enhanced rate of transfer at any temperature is observed in beakers as large as 8 mm diameter.

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Superfluid Flow and Local Gauge Invariance

Journal of the Physical Society of Japan ◽

10.1143/jpsj.48.793 ◽

1980 ◽

Vol 48 (3) ◽

pp. 793-798 ◽

Cited By ~ 1

Author(s):

Masakazu Ichiyanagi

Keyword(s):

Gauge Invariance ◽

Local Gauge ◽

Superfluid Flow ◽

Local Gauge Invariance

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Comments on the article: ‘The two-fluid model of the helium film’

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1973.0061 ◽

1973 ◽

Vol 333 (1593) ◽

pp. 261-263 ◽

Cited By ~ 5

Keyword(s):

Superfluid Helium ◽

Fluid Model ◽

Convection Velocity ◽

Thermodynamic Approach ◽

Helium Film ◽

Helium Films ◽

Third Sound ◽

Superfluid Flow ◽

Two Fluid Model ◽

Two Fluid

It is argued that the thermodynamic approach used by Goodstein and Saffman in their theory of thin superfluid helium films is incorrect. Their theory does not explain Keller’s experiment. The value they obtained for the convection velocity of third sound in a film with superfluid flow is consequently unfounded theoretically. Their calculation of third sound attenuation is shown to be incomplete.

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