1 research outputs found
Self-organization in He4 near the superfluid transition in heat flow and gravity
We investigate the nonlinear dynamics of He4 slightly below the superffluid
transition by integrating model F equations in three dimensions. When heated
from above under gravity, a vortex tangle and a sheetlike phase slip are
generated near the bottom plate. Then a self-organized superfluid containing
high-density vortices and phase slips grows upward into an ordinary superfluid.
The thermal resistance due to these defects produces a constant temperature
gradient equal to the gradient of the pressure-dependent transition temperature
. In this self-organized region, the temperature deviation
consists of a negative constant independent of the height
and time-dependent fluctuations. Its time-average is calculated in good
agreement with the experimental value (W.A. Moeur {\it et al.}, Phys. Rev.
Lett. 78, 2421 (1997)).Comment: 8 pages, 7 figure