Tuesday, August 14, 2012

1208.2647 (J. J. Hosio et al.)

Energy and angular-momentum balance in wall-bounded superfluid

J. J. Hosio, V. B. Eltsov, P. J. Heikkinen, M. Krusius, V. S. L'vov
An example of steady-state wall-bounded quantum turbulence is provided by the turbulent vortex front. In a rotating cylinder filled with originally vortex-free superfluid 3He-B, the front propagates axially and sets the superfluid in rotation. Our measurements of the front propagation at different angular velocities and temperatures down to 0.16Tc show that besides the energy-dissipation mechanisms, the transfer of angular momentum is increasingly important for the turbulent dynamics in the T -> 0 limit. We suggest a phenomenological model that describes the front velocity in terms of two effective mutual-friction parameters, which govern the energy and momentum balance, respectively. The residual values of these parameters in the T -> 0 limit differ by two orders of magnitude. In this limit, the efficient energy dissipation can be associated in traditional manner with the turbulent energy cascade toward small length scales, while the much less effective angular-momentum transfer causes decoupling of the superfluid from the rotating container.
View original: http://arxiv.org/abs/1208.2647

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