Cavitation Inception on a Circular Cylinder at Critical and Supercritical Flow Range

1986 ◽  
Vol 108 (4) ◽  
pp. 421-427 ◽  
Author(s):  
A. Ihara ◽  
H. Murai

Cavitation tests were performed in the critical and supercritical flow range on circular cylinders with and without boundary layer trip. Mean and fluctuating static pressures were meausred on the smooth circular cylinder from θ = 0 to 180° and on the tripped surface at θ = 104 and 106° corresponding to tripping wire location α = 38 and 40 deg. Through these measurements it was found that cavitation that closely resembles bubble ring cavitation reported on axisymmetric bodies took palce in a reattachment region of the laminar separation bubble for the critical flow range where the laminar separation bubble was present. For the supercritical flow range where the laminar separation bubble disappeared, smooth cavitation with small irregular bubbles at its rear part took place at a location about 100° from the stagnation point.

1981 ◽  
Vol 103 (4) ◽  
pp. 543-549 ◽  
Author(s):  
B. R. Parkin

Flow conditions surrounding bubble-ring cavitation inception on hemispherical headforms are analyzed with respect to the initiation of air diffusion into microbubbles as is observed to occur at fixed positions in the boundary layer. Fairly recent observations have shown this phenomenon to occur in the laminar separation bubble on the body. The analysis shows, in agreement with the body of experimental evidence now available, that gaseous growth must be preceded by a period of vaporous growth starting in regions of low pressure upstream of the laminar separation bubble. It also appears that the most favorable condition for the initiation of gaseous growth should occur when a typical vapor bubble reaches its maximum radius as it enters the laminar separation bubble. The conditions for the initiation of subsequent gaseous growth, once the cavitation bubble is stabilized in the laminar separation zone, are more demanding. Nevertheless, it is found that the liquid in the water surrounding the bubble in the separation zone is definitely supersaturated for most flows of experimental or practical interest. Therefore, gaseous growth, as well as vaporous growth, is definitely to be associated with the onset of bubble-ring cavitation on both theoretical and experimental grounds.


2012 ◽  
Vol 89 (4) ◽  
pp. 547-562 ◽  
Author(s):  
Daniele Simoni ◽  
Marina Ubaldi ◽  
Pietro Zunino

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