## 4aSA11. Acoustical scattering by a density contrast wedge.

### Session: Thursday Morning, May 16

### Time: 11:00

**Author: Anthony M. J. Davis**

**Location: Dept. of Math., Univ. of Alabama, Tuscaloosa, AL 35487-0350**

**Author: Robert W. Scharstein**

**Location: Univ. of Alabama, Tuscaloosa, AL 35487-0286**

**Abstract:**

Consider the three-dimensional scattering of a sound pulse generated by an
impulsive point source and incident upon a penetrable wedge, identified by a
density contrast. The wave speed is common to both regions and the radiation
condition of only outgoing waves at infinity is applied in all directions. At
the boundary of the wedge there is a pair of transmission conditions which
ensure continuity of the acoustic pressure and normal velocity. By using Fourier
transforms in time and parallel to the wedge generators and a
Kontorovich--Lebedev transform in the radial direction, as described by Jones
[Acoustic and Electromagnetic Waves, Oxford (1986)], both the exterior and
interior fields can be obtained as a sum of impulsive terms, some of which are
due to edge diffraction. If the wedge angle is a rational fraction of (pi), then
the residue series can be summed and, after careful consideration of when and
where impulsive disturbances can occur, the fields can be written in remarkably
simple closed forms. This solution provides the zero-order field for a
relatively small difference in wave speeds.

from ASA 131st Meeting, Indianapolis, May 1996