Investigation of Unsteady Sheet Cavitation and Cloud Cavitation Mechanisms

Autor:	D. H. Fruman, T. M. Pham, Frédérique Larrarte
Rok vydání:	1999
Předmět:	Flow visualization Physics Leading edge Jet (fluid) business.industry Mechanical Engineering Mechanics Instability law.invention Physics::Fluid Dynamics Pressure measurement Optics law Cavitation High-speed photography business FOIL method
Zdroj:	Journal of Fluids Engineering. 121:289-296
ISSN:	1528-901X 0098-2202
DOI:	10.1115/1.2822206
Popis:	Sheet cavitation on a foil section and, in particular, its unsteady characteristics leading to cloud cavitation, were experimentally investigated using high-speed visualizations and fluctuating pressure measurements. Two sources of sheet cavitation instability were evidenced, the re-entrant jet and small interfacial waves. The dynamics of the re-entrant jet was studied using surface electrical probes. Its mean velocity at different distances from the leading edge was determined and its role in promoting the unsteadiness of the sheet cavitation and generating large cloud shedding was demonstrated. The effect of gravity on the dynamics of the re-entrant jet and the development of interfacial perturbations were examined and interpreted. Finally, control of cloud cavitation using various means, such as positioning a tiny obstacle (barrier) on the foil surface or performing air injection through a slit situated in the vicinity of the leading edge, was investigated. It was shown that these were very effective methods for decreasing the amplitude of the instabilities and even eliminating them.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::4248b8d9579a81d075276c09167d269b https://doi.org/10.1115/1.2822206 Zobrazit plný text záznamu