Self noise of a supercavitating vehicle

The cavity of a supercavitating vehicle in water is maintained by the steady injection of gas from sources within the vehicle and cavity. An experimental and analytical investigation is being made to establish the spectrum of the acoustic ‘self noise’ produced at the nose of the vehicle. Measurements are made using a specially modified supercavity at the Penn State Applied Research Laboratory. Of particular interest is the sound generated by gas impingement on the cavity walls. In the experiment the gas enters the cavity in a radially symmetric pattern through a series of narrow jets. Experiments have been performed to measure the unsteady force applied to the gas-water interface by these jets, each one of which can then be modeled as a dipole source of sound radiating into the water.  A transfer function has been derived analytically that permits the self noise pressure at the nose of the vehicle to be expressed in terms of the pressure distribution on the cavity wall attributable to the gas jets.

Personnel: Professor M. S. Howe and Ms Alia Foley, BU; Professor T. A. Brungart and Mr. S. D. Young, Penn State University (Research supported by the Office of Naval Research Code 333).