### ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

## 2pAO5. A semianalytical method for the noise emission of finite size
objects in shallow water.

**Hasan N. Oguz
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*Dept. of Mech. Eng., Johns Hopkins Univ., Baltimore, MD 21218
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Point sources are commonly used in underwater ambient noise computations
to model wave breaking noise. A semianalytical solution to sound emission by a
finite size object in shallow water is developed. The coefficients of the
normal modes obtained by this technique are compared with the coefficients
given by the point source approximation for the case of a hemispherical bubble
cloud. The comparison is only good when the size of the bubble cloud is much
smaller than the acoustic wavelength. Substantial differences occur when the
radiation pattern near the bubble cloud deviates from a circular shape
associated with the point dipole emission. Accurate normal modes coefficients
given by the current method could be coupled with shallow water propagation
models used in ambient noise calculations. [Work supported by the Office of
Naval Research.]