Nonlinear profiles and spectra transformation in going from vibrating piston to traveling wave

Abstract

The effects of nonlinear relation between the radiating surface motion law and the traveling wave profile are studied. These effects are significant in the neighbor of the source for the vibration velocities compared with a sound speed. The source was modeled as a nonlinear vibrating system, namely, as a piston excited by external force and loaded by the medium. The temporal profiles and harmonics amplitudes of waves radiated by the piston at harmonic, wide-band (pulsed) and noise excitation are calculated. The effects of dynamic (regular) and stochastic wave generation are compared, and characteristic features of spectral transformation for these two cases are analyzed. Special attention is paid to the difference between the boundary nonlinear phenomena considered here and bulk effects due to nonlinear elastic properties of a medium. A possibility of observing such phenomena for the radiation of high intensity waves into the bubbly liquid is discussed. [Work supported by CRDF and RFBR.]