Measurements of the critical velocity of hydraulic cavitation in superfluid He-4
Abstract
In an effort to clarify the mechanism of the inception of phase transition in liquid helium, He II was made to cavitate in the flow through a glass constriction nozzle with a diameter of 0.45 mm, by using a fountain effect pump. Attainable critical velocities for incipient cavitation were obtained over a temperature range of 1.2 K to the lambda-point. It was found that the cavitation threshold was quite low, with an approximate range of 0.1 - 1.0 KPa. The result seems to show that, contrary to the hypothesis of nuclear bubbles, some kind of direct coupling between the state of flow of He II, probably superfluid turbulence, and the inception of cavitation may be responsible for the phenomena.
- Publication:
-
Advances in Cryogenic Engineering. Vol. 35B - Proceedings of the 1989 Cryogenic Engineering Conference
- Pub Date:
- 1990
- Bibcode:
- 1990ACGE...35..239N
- Keywords:
-
- Cavitation Flow;
- Critical Velocity;
- Cryogenic Cooling;
- Liquid Helium;
- Phase Transformations;
- Superfluidity;
- Cryopumping;
- Pressure Gradients;
- Space Missions;
- Temperature Dependence;
- Engineering (General)