Numerical simulation of acoustic wave phase conjugation in active media

Godunov-type computation schemes are applied to numerical simulations of wa ve propagations in time-dependent heterogeneous media (solids and liquids). The parametric phase conjugation of a wide band ultrasound pulse is consid ered. The supercritical dynamics of the acoustic field is described fur one -dimensional systems containing a parametrically active solid. The impulse response function, numerically calculated for a finite active zone in an in finite medium above the threshold of absolute parametric instability, is in a good agreement with the analytical asymptotic theory. The supercritical evolution of the acoustic field spatial distribution is studied in detail f or parametric excitations in an active zone of a solid layer, loaded by a s emi-infinite liquid on one side and free on the other. (C) 2001 Acoustical Society of America. [DOI: 10.1121/1.1328794].