F332 ベンチュリ管を用いたヘリウムの 2 つの液相におけるキャビテーション

概要

論文の詳細を見る
Helium has two liquid phases, He I and He II. We studied cavitation flows in two liquid helium phases using a Venturi channel. It is found that there are many differences in cavitation between He I and He II. It is found from pressure measurement, that the pressure loss in cavitation flow of He II is larger than of He I. It is also seen from visualization picture He II cavitation bubbles rapidly grow up and numerous small vapor bubbles are generated in the primitive stage of cavitation flow. On the other hand, He I cavitation bubbles still remain in the state of massive individual tiny vapor bubbles until the collapse of the cavitation far downstream. It is recognized that there is a definite difference in the temperature decrease between He I and He II cavitation flows. Inside of a cavitation flow, the temperature decreases by maximum 100mK in He I, but in He II the temperature drop tends to saturate about 25mK whatever the flow velocity increases.
2001-07-31