Investigation of Cavity Cycling for Ventilated and Natural Cavities.

摘要

The frequency of cavity cycling due to the re-entrant jet was measured for a 45 degrees conical-nosed model having a 1-inch diameter afterbody. Spectral analyses of the output of an internally mounted transducer were performed to determine the cycling frequency. The cavity cycling was also measured from high-speed movies taken of the model cavitation. Data for both natural (vaporous) and ventilated cavities were obtained and compared with data from hydroballistics tank tests of NSWC and previous water tunnel tests. The cavity cycling frequency presented as a Strouhal number increases with cavitation number. Frequency data, measured by the transducer, for vaporous cavitation were higher than the results for similar ventilated cavities. However, measurements from high-speed movies show close agreement between cycling frequency for both types of cavitation. (Author)