Acoustic ray theory applied to vortex refraction
Abstract
Acoustic ray equations are derived from geometrical considerations, thereby avoiding an ambiguity of sign associated with acoustic refraction by vortices. Some exact solutions are given for simple velocity distributions. A numerical example shows that rays are turned through large angles even when the greatest Mach number in the vortex is quite low; specifically for M = 0.3, the deflection of rays passing near the center of the vortex is about 1 radian. The antisymmetry of the scattered field about a line through the acoustic source and the center of the vortex is investigated; the antisymmetry is found to exist, which is consistent with results obtained by methods independent of ray theory.
 Publication:

Journal of the Institute of Mathematics and Its Applications
 Pub Date:
 January 1977
 Bibcode:
 1977JIMIA..19....1B
 Keywords:

 Acoustic Propagation;
 Axisymmetric Flow;
 Refraction;
 Vortices;
 Differential Equations;
 Flow Equations;
 Flow Velocity;
 Shear Flow;
 Sound Intensity;
 Two Dimensional Flow;
 Acoustics