European Turbulence Conference 2015

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11:45
15 mins

Mutual-Friction Coefficients in Two-Dimensional Superfluids: From the Gross-Pitaevskii equation to the Hall-Vinen-Bekharevich-Khalatnikov Two-fluid Model
Vishwanath Shukla, Marc Brachet, Anupam Gupta, Rahul Pandit

Session: Superfluids 1
Session starts: Wednesday 26 August, 10:30
Presentation starts: 11:45
Room: Room E

Vishwanath Shukla (Indian Institute of Science, Bangalore, India)
Marc Brachet (Ecole Normale Superieure, Paris, France)
Anupam Gupta (Department of Physics, University of Rome Tor Vergata, Rome, Italy)
Rahul Pandit (Indian Institute of Science, Bangalore, India)

Abstract:
We start from the two-dimensional Gross-Pitaevskii equation (GPE) and develop algorithms for the ab-initio determination of the temperature ($T$) dependence of the mutual-friction coefficients, $\alpha$ and $\alpha'$, and the normal-fluid density $\rho_n$, which appear as parameters in the Hall-Vinen-Bekharevich-Khalatnikov (HVBK) two-fluid model for a superfluid. In the second part of our study, we elucidate the statistical properties of two-dimensional, homogeneous, isotropic superfluid turbulence in the simplified HVBK model, with values for the mutual-friction coefficients that are comparable to those we obtain from the first part of our study.