The parabolic approximation for sound propagation in a stratified moving medium
Abstract
Propagation of sound in a stratified moving medium is discussed through an extension of the parabolic approximation to the acoustic equations of motion for short wavelengths. The parabolic approximation is related to the theory of geometric acoustics, and it is shown that it yields an improvement in accuracy over geometric theory. Also, the approximation corrects cumulative failures of geometric theory which occur when sound propagates many wavelengths from its source. The theory is illustrated by application to simple examples of quasiplane wave propagation.
 Publication:

American Institute of Aeronautics and Astronautics Conference
 Pub Date:
 October 1977
 Bibcode:
 1977aiaa.confT....M
 Keywords:

 Aeroacoustics;
 Approximation;
 Equations Of Motion;
 Parabolic Differential Equations;
 Sound Propagation;
 Stratified Flow;
 Error Analysis;
 Ideal Gas;
 Inviscid Flow;
 Plane Waves;
 Wave Equations;
 Acoustics