Application of PIV technique to cavitating flows of liquid helium

摘要

PIV technique was applied to the measurement of bubbly flow of cavitating liquid helium driven by a bellows pump. In the present PIV application the velocity of cavitation bubbles is measured without adding any seeding particles. The flow field, the downstream of the Venturi throat, is separately illuminated by two stroboscopes through an optical window of the cryostat, and subsequent two successive pictures of cavitaion bubbles are taken by a digital CCD camera. The image information of the two pictures is analyzed with the aid of a PIV algorithm to yield a 2-D velocity distribution of cavitation bubbles. It may be concluded that the application of PIV technique is of great use in the quantitative study of cavitaion flows of He Ⅰ and He Ⅱ.