Code 130B, Coastal Systems Sta., Panama City, FL 32407-7001
A transition-matrix formulation of the field scattered by a three-dimensional, multilayered, poroelastic obstacle embedded in a poroelastic host is obtained by extending Peterson and Strom formulation for scalar waves [B. Peterson and S. Strom, J. Acoust. Soc. Am. 57, 2--13 (1975)]. An exact solution of the vector Biot equations is obtained, obeying all boundary conditions prescribed on all boundaries of the layered obstacle. By numerically implementing the solution for general poroelastic media, scattering with hosts and obstacles made of loss general media is conveniently predicted by choosing material parameters in a limiting sense. Examples are presented to study the scattering dynamics of layered spheres and spherical shells embedded in fluid and poroelastic hosts.