Nonlinear Distortion and Attenuation of Intense Acoustic Waves in Lossy Media Obeying a Frequency Power Law

Abstract

Nonlinear propagation of a periodic wave and a single pulse with a shack front through a lossy medium is studied theoretically. The medium is characterized by the frequency dependence of the attenuation coefficient obeying a power law and by a corresponding dispersion law. The numerical modeling of the problem is performed on the basis of the modified spectral approach. It is found that the exponent of the aforementioned power law essentially affects the efficiency of nonlinear interactions, the distortion of the wave profile, and the absorption of acoustic energy in the nonlinear mode. The stability of the discontinuous structure of a shock front is investigated for different power laws close to a linear one. The possibility of pulsed diagnostics of the parameters of the frequency power law governing the attenuation in the medium by the shape of a single pulse with a shock front after its passage through the medium is considered. (C) 2000 MAIK "Nauka/Interperiodica".