Author(s)

Guoyi Peng^1*, Ayaka Wakui², Yasuyuki Oguma¹, Seiji Shimizu¹, Hong Ji³

¹Department of Mechanical Engineering, College of Engineering, Nihon University, Koriyama, Japan.
²Graduate School of Engineering, Nihon University, Koriyama, Japan.
³College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, China.

The behavior of cavitation cloud shedding in submerged water jets issuing from a sheathed pipe nozzle is investigated experimentally by high-speed camera visualization observation. Experiments are carried out under different cavitation numbers decreased to 0.01 with increase of the injection pressure, and the frequency spectrum of cavitation cloud shedding is evaluated by statistical analysis of a sequence of high-speed camera images. Experiments demonstrate that cavitation clouds appear when the cavitation number σ decreases to the level of 0.5-0.7 and developed cavitation clouds shed downstream periodically at multiple frequencies. The low frequency components of cavitation cloud shedding is basically dependent upon the pressure pulsation of plunger pump, which is often employed in various industry application of water jets. However, the high frequency components are closely related to the shedding of vortexes and the collapsing of cavitation clouds, which are dependent on the flow structure of submerged jets and the property of cavitation clouds consisted of numerous bubbles.

Water Jet, Cavitation, Cavitation Cloud, Visualization, Image Analysis

Peng, G. , Wakui, A. , Oguma, Y. , Shimizu, S. and Ji, H. (2018) Periodic Behavior of Cavitation Cloud Shedding in Submerged Water Jets Issuing from a Sheathed Pipe Nozzle. Journal of Flow Control, Measurement & Visualization, 6, 15-26. doi: 10.4236/jfcmv.2018.61002.