Transition to turbulence for a quartz tuning fork in superfluid He-4

Bradley, D. I. and Fear, M. J. and Fisher, S. N. and Guénault, A.M. and Haley, R. P. and Lawson, C. R. and McClintock, P. V. E. and Pickett, G. R. and Schanen, R. and Tsepelin, V. and Wheatland, L. A. (2009) Transition to turbulence for a quartz tuning fork in superfluid He-4. Journal of Low Temperature Physics, 156 (3-6). pp. 116-131. ISSN 0022-2291

[img]
Preview
PDF (JLTPforksCorrectedPostPrint)
JLTPforksCorrectedPostPrint.pdf - Accepted Version

Download (566kB)

Abstract

We have studied the resonance of a commercial quartz tuning fork immersed in superfluid He-4, at temperatures between 5 mK and 1 K, and at pressures between zero and 25 bar. The force-velocity curves for the tuning fork show a linear damping force at low velocities. On increasing velocity we see a transition corresponding to the appearance of extra drag due to quantized vortex lines in the superfluid. We loosely call this extra contribution "turbulent drag". The turbulent drag force, obtained after subtracting a linear damping force, is independent of pressure and temperature below 1 K, and is easily fitted by an empirical formula. The transition from linear damping (laminar flow) occurs at a well-defined critical velocity that has the same value for the pressures and temperatures that we have measured. Later experiments using the same fork in a new cell revealed different behaviour, with the velocity stepping discontinuously at the transition, somewhat similar to previous observations on vibrating wire resonators and oscillating spheres. We compare and contrast the observed behaviour of the superfluid drag and inertial forces with that measured for vibrating wires.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Low Temperature Physics
Additional Information:
The final publication is available at Springer via http://dx.doi.org/10.1007/s10909-009-9901-3
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3104
Subjects:
ID Code:
61513
Deposited By:
Deposited On:
03 Jan 2013 14:33
Refereed?:
Yes
Published?:
Published
Last Modified:
28 Nov 2020 01:41