ACOUSTIC-WAVE PROPAGATION IN 2-DIMENSIONAL MEDIA CONTAINING SMALL-SCALE HETEROGENEITIES

We study the propagation of an acoustic wave through a two-dimensional medium with many small-scale inhomogeneities. The integral-equation m ethod we employ compares favorably with respect to effective-medium me thods in the sense that it handles multiple scattering to any order, a nd is numerically more efficient than straightforward discretization m ethods thanks to our choice of expansion functions for the acoustic fi eld at the heterogeneities. In numerical experiments we find apparent attenuation and dispersion of the incident wave field and compare with a self-consistent method originated by Willis and coworkers to invest igate the expected breakdown of that type of method when multiple scat tering becomes more important. Copyright (C) 1998 Elsevier Science B.V .