3D acoustic scattering from an irregular fluid waveguide via the BEM

The BEM is used to calculate the variation in the pressure held generated b y a dilatational point load inside a channel filled with a homogeneous flui d, in the presence of an irregular floor. The Green's functions are defined in the frequency domain and obtained by superposing virtual acoustic sourc es combined so as to generate the boundary conditions of the free or rigid surfaces of the channel. The responses in the time domain are obtained by m eans of Fourier transforms, making use of complex frequencies. The main fea tures and spectral representation of the signals scattered by irregular flo ors are then described and used to elucidate the most important aspect of w ave acoustics, which can provide the basis for the development of non-destr uctive testing and imaging methods. (C) 2001 Elsevier Science Ltd. All righ ts reserved.