Flow of He II due to an oscillating grid in the low-temperature limit.
The macroscopic flow properties of pure He II are probed in the limit of zero temperature using an oscillating grid. As the oscillation amplitude passes a first critical threshold, the resonant frequency starts decreasing but the flow remains nondissipative. Beyond a second critical amplitude, the flow undergoes a transition to turbulence and becomes dissipative. Nonlinearity and hysteresis observed between the thresholds are attributed to a boundary layer of quantized vortices.
Nichol
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Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Skrbek
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Hendry
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McClintock
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