Nonlinear Effects in Wave Propagation

Abstract

Linear theory for different kinds of waves in fluids has so far been developed. The superposition principle holds in this theory, i.e., waves of different kinds as well as different modes of waves of the same kind propagate without interaction with each other. One must bear in mind, however, that linear equations are only approximate ones and the original hydrodynamic equations are substantially nonlinear. It is important to clarify the conditions under which a linear approximation is adequate and to consider new effects caused by nonlinear terms in the equations. To this very question is this chapter devoted.