Flow visualization study of thermal counterflow jet in He II

✍ Scribed by M. Murakami; N. Ichikawa

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 551 KB
• Volume: 29
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(89)90276-2

✦ Synopsis

A method of flow visualization in superfluid helium has been developed by the use of solid H2-D 2 particles and hollow glass spheres as neutrally buoyant tracers to follow the normal component flow. It is applied to the study of a thermal counterflow jet based on pattern recognition of jet profiles and on measurement of mean normal velocity. Traceability of both kinds of tracers is satisfactory up to a few cm s -1. The evolution of jet pattern is found to vary widely depending on the Reynolds number, quite similar to usual viscous fluid jets, ranging from laminar to fully turbulent ones. The large-scale vortical motion and the entrainment of the surrounding He II into jet are clearly seen in fully developed turbulent-like jets. The calculation of the total momentum flux from the normal fluid velocity profiles seems to indicate that the zero-relative-velocity situation between the normal and super components is reached in jets as suggested in previous experiments.