Counterflow-induced macroscopic vortex rings in superfluid helium: visualization and numerical simulation
✍ Scribed by G. Stamm; F. Bielert; W. Fiszdon; J. Piechna
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 654 KB
- Volume
- 193
- Category
- Article
- ISSN
- 0921-4526
No coin nor oath required. For personal study only.
✦ Synopsis
The existence of macroscopic vortex rings produced without any moving mechanical part, simply bv releasing a heat pulse of appropriate intensity and duration at the closed end of a circular counterflow channel, will be provcd, From consecutive pictures, taken from a light sheet crossing the axis of symmetry, the formation and further propagation of the vortex rings can be studied. The average translational velocity as well as the w~rtex parameters like ring and core diameter are compared with the obserw~tions found for w~rtex rings generated by a moving piston. Due to the interaction of superfluid and normal fluid turbulence the countcrflow-induced vortex rings arc turbulent and appear unstable. The experimental observations are compared with numerical simulations where thc boundary conditions for the normal fluid and the superfluid velocity have been chosen appropriately.