### ASA 127th Meeting M.I.T. 1994 June 6-10

## 2aEA6. Application of the T-matrix method to the numerical modeling of an
array of active acoustic transducers.

**Steven R. Baker
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*Physics Dept., U. S. Naval Postgraduate School, Monterey, CA 93943
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**Clyde L. Scandrett
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*U. S. Naval Postgraduate School, Monterey, CA 93943
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**Arthur Ruiz
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*Brazilian Navy
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The conventional T-matrix method is a procedure for the computation of the
far-field scattering of a plane wave by a compact but otherwise arbitrary
collection of scatterers [cf. V. V. Varadan and V. K. Varadan, J. Acoust. Soc.
Am. 70, 213--217 (1981)]. Its strength is that the effects of multiple
scattering to all orders are rigorously and self-consistently obtained from the
single-scattering properties of each scatterer in a free-field environment. For
acoustic waves, the T-matrix method has been extended to the case where the
source of the scattered radiation is the scatterers themselves, i.e., to the
case of an array of active transducers. As an example, the method has been
applied to an array of piezoelectric spherical shell sonar transducers. A
description of the T-matrix method applied to active acoustic arrays will be
given. The use of the finite-element code ATILA [J. N. Decarpigny et al., J.
Acoust. Soc. Am. 78, 1499--1507 (1985)] to compute the single-transducer
radiation and scattering properties will be described. Results will be compared
to Pritchard's approximation. [Work sponsored in part by the Naval Postgraduate
School and the Naval Undersea Warfare Center.]