Effect of surface ship internal fluid containers on external acoustic intensity measurements
Smith, Amy Ruth
MetadataShow full item record
The nearfield acoustic intensity resulting from vibration transmitted from a main machinery foundation through supporting structure and fluid containing tanks into the hull structure, and then into the surrounding fluid has been studied for a scale model of a frigate ship. The scale model is 1:10 and the scaled frequency range is 640 Hz to 15 kHz. Acoustic pressure is measured on adjacent cylindrical contours close to the surface of the underwater vibrating surface with the fluid-containing tank first empty and the full. The time-averaged acoustic intensity is then calculated from the pressure cross-spectrum. The resulting sound intensity patterns over the surface of the vibrating structure are studied obtain an insight as to which parts of the structure are primarily responsible for the radiated noise. The spatial characteristics of the acoustic intensity patterns are indicators of the energy exchange between the structure and the acoustic medium. Additionally, the total radiated power has been calculated from the local acoustic intensity measurements and these experimental results have been compared with sound radiation measurements from a comparable model of scale 1:6.25.
CIVINS (Civilian Institutions) Thesis documentApproved for public release ; distribution is unlimited
Showing items related by title, author, creator and subject.
Corley, M.S.; Santiago, F.; T. Martinez; Agrawal, B.N. (2011);The Navy is interested in horizontal laser propagation studies in a maritime environment, near the ocean surface, for applications including imaging and high-energy laser propagation. The Naval Postgraduate School (NPS) ...
Statistics of acoustic pulse signals through nonlinear internal waves on the continental shelf of the northeastern South China Sea Reeves, Justin M. (Monterey, California. Naval Postgraduate School, 2008-03);1 km), high-frequency, nonlinear internal depression and elevation waves superimposed on the internal tides. Through the use of an empirical sound-speed field and a coupled, normal-mode acoustic propagation model, the ...
Sensitivity of tropical-cyclone models to the surface drag coefficient in different boundary-later schemes Smith, Roger K.; Montgomery, Michael T.; Thomsen, Gerald L. (Royal Meteorological Society, 2014-04);The recent study of the sensitivity of tropical-cyclone intensification to the surface drag coefficient in a three-dimensional model by Montgomery et al. is extended to include a wind-speed-dependent drag coefficient and ...