Mechanism of Cloud Cavitation and Its Control
| Autor: | Yasutaka Kawanami, Hiroharu Kato, Hajime Yamaguchi, Masaharu Tanimura, Yoshinori Tagaya, Masatsugu Maeda |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Journal of the Society of Naval Architects of Japan. 1995:41-50 |
| ISSN: | 1884-2070 0514-8499 |
| Popis: | This paper describes the experimental result of cloud cavitation on a two-dimensional foil. Cloud cavitation was observed by a high speed camera and a high speed video camera to know the mechanism of cloud cavitation. Ink was injected to investigate the reserve flow (re-entrant jet) at the bottom of the sheet cavity. The flow around the sheet cavity was measured by a laser doppler velocimeter. By applying conditional sampling technique on the flow measurement, unsteady flow field was examined with the motion of cloud cavitation.A small square bar was attached on the foil surface and the effect on the cloud cavitation was investigated.The conclusion are as follows : (1) The shedding of cloud cavitation is caused by re-entrant jet. (2) The re-entrant jet starts at the rear center of a sheet cavity and spreads to the leading edge.The re-entrant jet disturbs the sheet cavity and the sheet cavity collapses into a mass of bubbly cavities. When the re-entrant jet reaches the cavity leading edge, the shedding of cloud cavity occurs.(3) A bar attached on the foil surface reduces the re-entrant flow, resulting in the reduction of cloud cavitation shedding. A ditch on the foil surface gives the similar effect on the cloud cavitation. |
| Databáze: | OpenAIRE |
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