An intrinsic velocityindependent criterion for superfluid turbulence
Abstract
Hydrodynamic flow in classical and quantum fluids can be either laminar or turbulent. Vorticity in turbulent flow is often modelled with vortex filaments. While this represents an idealization in classical fluids, vortices are topologically stable quantized objects in superfluids. Superfluid turbulence is therefore thought to be important for the understanding of turbulence more generally. The fermionic ^{3}He superfluids are attractive systems to study because their characteristics vary widely over the experimentally accessible temperature regime. Here we report nuclear magnetic resonance measurements and numerical simulations indicating the existence of sharp transition to turbulence in the B phase of superfluid ^{3}He. Above 0.60T_{c} (where T_{c} is the transition temperature for superfluidity) the hydrodynamics are regular, while below this temperature we see turbulent behaviour. The transition is insensitive to the fluid velocity, in striking contrast to current textbook knowledge of turbulence. Rather, it is controlled by an intrinsic parameter of the superfluid: the mutual friction between the normal and superfluid components of the flow, which causes damping of the vortex motion.
 Publication:

Nature
 Pub Date:
 August 2003
 DOI:
 10.1038/nature01880
 arXiv:
 arXiv:condmat/0304586
 Bibcode:
 2003Natur.424.1022F
 Keywords:

 Condensed Matter;
 Nonlinear Sciences  Chaotic Dynamics;
 Physics  Fluid Dynamics
 EPrint:
 Revtex file