Physics – Condensed Matter – Other Condensed Matter
Scientific paper
2008-11-18
J. Low Temp. Phys. 153, 189-196 (2008)
Physics
Condensed Matter
Other Condensed Matter
5 pages and 3 figures. Proceedings of the "Low Temperature Quantum Phenomena and Devices": Symposium in Espoo, Finland, March
Scientific paper
10.1007/s10909-008-9834-2
The critical velocity vc for the onset of turbulent drag of small spheres oscillating in superfluid 4He is frequency dependent (omega/2pi from 100 Hz to 700 Hz) and is described by vc = 2.6sqrt(kappa*omega), where kappa is the circulation quantum. A qualitative analysis based on a recent theory of the onset of superfluid turbulence gives vc = sqrt(8*kappa*omega/beta), where beta is of order 1 and depends on the coefficients of mutual friction. This agrees well with the data and implies that vc is a universal critical velocity that is independent of geometry, size, and surface properties of the oscillating body. This is confirmed by comparing our data on spheres with vc obtained with other oscillating structures by other groups. Numerical simulations indicate somewhat larger critical velocity, above which a rapid increase in vortex length is observed.
Hänninen R.
Schoepe Wilfried
No associations
LandOfFree
Universal Critical Velocity for the Onset of Turbulence of Oscillatory Superfluid Flow does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Universal Critical Velocity for the Onset of Turbulence of Oscillatory Superfluid Flow, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Universal Critical Velocity for the Onset of Turbulence of Oscillatory Superfluid Flow will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-100804