Acoustic wave propagation in two-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 method we employ compares favorably with respect to effective-medium methods in the sense that it handles multiple scattering to any order, and is numerically more efficient than straightforward discretization methods thanks to our choice of expansion functions for the acoustic field 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 investigate the expected breakdown of that type of method when multiple scattering becomes more important. Copyright (C) 1998 Elsevier Science B.V.