Accession Number : ADA504594


Title :   Investigations of the Sound Generated by Supercavity Ventilation


Descriptive Note : Final technical rept.May 2006-May 2009


Corporate Author : BOSTON UNIV MA COLL OF ENGINEERING


Personal Author(s) : Howe, Michael S ; Foley, Alia W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a504594.pdf


Report Date : 20 Aug 2009


Pagination or Media Count : 168


Abstract : An investigation is made of the sound generated by the impingement of a ventilating jet on the interface of a ventilated supercavity. A ventilated supercavity is a gaseous envelope generated around an underwater vehicle that allows for order of magnitude increases in vehicle speeds. Hydrodynamic noise generated by the supercavity can interfere with successful vehicle deployment A principal mechanisms of noise generation is believed to be the impingement of ventilating gas jets on the gas-water cavity wall. An understanding of this interaction has been developed by analysis of a series of model problems which approximate the geometry and physical mechanisms involved in the jet-cavity interaction. The first problem is that of a spherical, gas-filled cavity in water whose surface is excited by a planar ring of axially projecting jets. The second involves a theoretical and experimental study of a jet of infinitesimal cross-section impinging at nonnal incidence on the gas-water interface. The final problem makes use of a creeping mode diffraction theory to estimate the 'self-noise' produced by the impinging jets on the solid nose of the vehicle.


Descriptors :   *NOISE GENERATORS , *HYDRODYNAMICS , *SELF NOISE , *VENTILATION , SOUND , GASEOUS DIFFUSION SEPARATION , JET FLOW , IMPINGEMENT , PLANAR STRUCTURES , MODELS , UNDERWATER VEHICLES , VELOCITY , CREEP


Subject Categories : Acoustics
      Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE