COMPARISON OF THE RAYLEIGH AND T-MATRIX THEORIES OF SCATTERING OF SOUND FROM AN ELASTIC SHELL

The Rayleigh and T-matrix mathematical formalisms of scattering of sound from an elastic shell are established and compared. It is shown that the two formalisms have a unique solution and are theoretically equivalent when used to calculate the pressure field sufficiently far away from the obstacle. From a numerical point of view, the closeness of the results obtained with the two methods does not depend on the validity of the Rayleigh hypothesis. These results enable one to analyze the validity of the wave superposition and retracted boundary integral formalisms when the auxiliary retracted surface is located inside the inscribed sphere. Some comments are made about the numerical results expected from these methods.