Acoustic scattering by baffled flexible surfaces: the discrete optical theorem
The optical theorem for acoustic scattering by baffled membranes and plates relates the total cross section of the scattered field, the directivity factor in the specular direction, and the energy dissipated by the structure. It is basically a statement of conservation of power. In this paper it is demonstrated that the discrete formulation of these problems, obtained by a Galerkin approximation, exactly satisfies the optical theorem. This discrete relationship holds regardless of the choice of basis functions and the size of the truncated system N. Thus, the adherence of the approximate numerical results to the power conservation law does not necessarily imply its accuracy.
Kriegsmann
GA
Department of Mathematical Sciences, New Jersey Institute of Technology, Newark 07102, USA.