Nonlinear distortion and attenuation of intense acoustic waves in lossy media obeying a frequency power law

Nonlinear propagation of a periodic wave and a single pulse with a shack fr ont through a lossy medium is studied theoretically. The medium is characte rized 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 aff ects the efficiency of nonlinear interactions, the distortion of the wave p rofile, and the absorption of acoustic energy in the nonlinear mode. The st ability of the discontinuous structure of a shock front is investigated for different power laws close to a linear one. The possibility of pulsed diag nostics of the parameters of the frequency power law governing the attenuat ion in the medium by the shape of a single pulse with a shock front after i ts passage through the medium is considered. (C) 2000 MAIK "Nauka/Interperi odica".