[GTP] GTP Seminar at NCAR April 23

[Silvia Gentile]

Marc Brachet
CNRS, France

April 23, 2010
Mesa Laboratory, Chapman Room
Lecture 3:30pm


Simulations of Finite-temperature Superfluids using the Truncated 
Gross-Pitaevskii Equation

We first give a short review of the thermalization that is known to take 
place in the truncated (finite range of spatial Fourier modes) Euler 
equation for incompressible fluids. The statistical equilibria of the 
(conservative) Gross-Pitaevskii Equation (GPE) dynamics will then be 
characterized using an algorithm based on a stochastically forced 
Ginzburg-Landau equation (SGLE) that directly generates grand canonical 
distributions. A standard finite-temperature second-order ?-transition 
will be exhibited. A new turbulent mechanism of GPE thermalization at 
small scales through a direct cascade of energy will be demonstrated. 
Dynamical counter-flow effects on vortex evolution will be investigated 
and a dilatation of vortex rings will be obtained for counter flows 
larger than their longitudinal velocity.






-- 
Silvia Gentile
NCAR IMAGe
1850 Table Mesa Drive
Boulder, CO 80305
www.image.ucar.edu