Radiation and Scattering at Oblique Incidence from Submerged Oblong Elastic Bodies
Abstract
The resonant behavior of solid or hollow oblong submersed elastic objects is studied both theoretically and experimentally. The resonances have been studied directly, by a calculation of surface wave displacements, or inferentially, by calculations or observations of echoes from plane incident acoustic waves with axial, broadside, or general oblique incidence onto the submersed objects. For the latter, we considered solid or hollow spheroids, or cylinders with flat or with hemispherical ends. Resonances are obtained theoretically from the phase matching of surface waves, which physically form standing waves in this case. A bar wave picture of resonant vibration has also been considered; it is shown to apply in the low-ka region while surface wave pictures apply in the high-ka region while surface wave pictures apply in the high-ka region, and the two pictures merge in the intermediate region. The dispersion of surface waves along the object for axial incidence is treated exactly. For broadside incidence, simultaneous excitation of meridional and circumferential surface wave is noted. The same surface wave picture applies for sound radiation from these objects following point excitation. Acoustic scattering, shallow water, waveguide propagation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1992
- Accession Number
- ADA257928
Entities
People
- Herbert Uberall
- Michael F. Werby
- Russel D. Miller
- Xueyang Bao
Organizations
- United States Naval Research Laboratory