00000nam 2200000zi 4500 9.943037 CaOODSP 20241203121833 m o d f cr bn||||||||| 240909e199003##nscad ob f000 0 eng d CaOODSP eng rda CaOODSP eng eng fre D68-21/26-1990E-PDF Sponagle, Neil Charles, 1955- author. Noise from tip vortex and bubble cavitation / Neil C. Sponagle ; approved by L.J. Leggat. Dartmouth, Nova Scotia : National Defence, Research and Development Branch, Defence Research Establishment Atlantic, March 1990. 1 online resource (iv, 36 pages) : illustrations, graphs. text txt rdacontent computer c rdamedia online resource cr rdacarrier Technical memorandum ; 90/202 Digitized edition from print [produced by Defence Research and Development Canada]. Includes bibliographical references (page 33). "This paper presents results from experiments designed to study the sound from different types of propeller cavitation. The propellers used in the tests produced tip vortex and travelling bubble cavitation. The spectral content, directivity, and waveform of the far-field sound were measured, in essentially free-field conditions, up to 100 kHz. These data were then correlated with information about the cavity dynamics, obtained from visual observations. Vibrational modes on the tip vortex cavities produced sound at characteristic frequencies. Bubble cavitation by itself produced very broadband noise, and strongly affected the vortex cavitation noise mechanisms if the free bubbles entered the tip vortices. The noise from both kinds of cavitation was directional"--Abstract, page ii. Includes abstracts in English and French. Propellers Cavitation. Propellers Noise. Cavitation noise. Hélices Cavitation. Hélices Bruit. Cavitation Bruit. Defence Research Establishment Atlantic, issuing body. D.R.E.A. technical memorandum ; 90/202. (CaOODSP)9.941838 PDF 1.37 MB https://publications.gc.ca/collections/collection_2024/rddc-drdc/D68-21-26-1990-eng.pdf