Numerical solution of conservation equations arising in linear wave theory  Application to aeroacoustics
Abstract
A method is developed for solving the conservation equations which describe the propagation of linear waves in slightly inhomogeneous and dispersive media. The method is based on a differentiation of the characteristic system with respect to the initial parameter space. The method can also be used in cases in which the field is reflected by solid boundaries. The approach employed makes use of a set of jump conditions which serve to reinitiate the numerical integration when a reflection occurs. The implementation of the described method is illustrated with the aid of examples related to aeroacoustics. It is pointed out that the calculation cannot be performed in the vicinity of caustics. The method does not apply either to cases of nonlinear propagation where the raytube area depends on the wave amplitude itself. The given examples are concerned with the acoustic radiation from a hot subsonic jet, the acoustic radiation from a nozzle exit, and threedimensional refraction by a jet flow.
 Publication:

Journal of Fluid Mechanics
 Pub Date:
 December 1977
 DOI:
 10.1017/S0022112077001293
 Bibcode:
 1977JFM....83..465C
 Keywords:

 Acoustic Propagation;
 Aeroacoustics;
 Conservation Equations;
 Wave Propagation;
 Jet Flow;
 Nozzle Flow;
 Refracted Waves;
 Subsonic Flow;
 Variational Principles;
 Wave Reflection;
 Physics (General)