Accession Number:

AD0611167

Title:

THE INFLUENCE OF FREE AIR BUBBLES ON CAVITY VOLUME AND THE ASSOCIATED NOISE SIGNATURE,

Descriptive Note:

Corporate Author:

OCEANICS INC PLAINVIEW N Y

Personal Author(s):

Report Date:

1964-08-01

Pagination or Media Count:

66.0

Abstract:

The series of investigations concerned a study of cavity volume and how the volume was affected by the presence or absence of free air bubbles in the test stream. The cavity was of an intermittent type created when a specially designed propeller passed through a reduced flow region wake. The size or volume of cavity investigated was such that the largest had a volume greater than 30 times the smallest. In conjunction with the volume studies, measurements were made of the noise characteristics of the cavities employing one third octave analysis. Key conclusions are a free gas bubbles in the water significantly affects the cavity volume, b the cavity volume generally appears to be directly associated with the amplitude of the noise signature for a given water condition, c bubble-filled water tends to produce smaller signature amplitudes than bubble-free water, d the higher frequencies 10 kc and above are superior to lower frequencies in detecting the existence of cavitation not including distance considerations. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE