Nonlinear acoustic behavior at a caustic

Abstract : The paper is concerned with modifying the basic theory of sonic booms to include nonlinear effects not properly accounted for in the neighborhood of a caustic. The basic theory accounts for nonlinear effects on the propagation of the pressure signal down a ray tube, but the concept of ray tubes is a linear one. The envelope of the rays is a caustic surface; this surface is the locus of cusps in the acoustic wave fronts. Interest is in the detailed structure of the wave front as it reflects at a caustic surface. (Author)