## 2pUW3. Scattering from a fluid loaded elastic spherical shell in proximity to a rough interface: Numerical results.

### Session: Tuesday Afternoon, May 14

### Time: 1:50

**Author: Judy Smith**

**Author: Garner C. Bishop**

**Location: Naval Undersea Warfare Ctr. Div., Newport, RI 02840**

**Abstract:**

A null field T-matrix formalism is developed and used to calculate
plane-wave scattering from a fluid loaded elastic spherical shell in proximity
to sound hard, sound soft, fluid--fluid, and fluid--elastic interfaces with
periodic surface roughness. For each type of interface, the Helmholtz--Kirchhoff
integral representation of the various scattered pressure and displacement
fields are constructed; the surface fields are required to satisfy the
appropriate boundary conditions and the scattered fields are required to satisfy
the extended boundary condition. Spherical basis functions are used to construct
a free field T-matrix for the elastic shell and rectangular vector basis
functions are used to construct a representation of the free field T-matrix for
the rough interface. The free field T-matrices are introduced into the
Helmholtz--Kirchhoff equations for the scattered fields and the null field
equations for the shell-interface system and an ``exact'' analytical solution is
obtained. Numerical results are obtained that demonstrate the effects of
boundary type, elastic parameters, roughness geometry, amplitude, and slope on
the scattered pressure field and on the ability to ``see'' the scatter from the
elastic shell.

from ASA 131st Meeting, Indianapolis, May 1996