The Energy Flow For A Spherical Acoustic Lens: Ray vs. Wave Methods
Document Type
Article
Publication Date
2008
Publication Title
The Journal of the Acoustical Society of America
DOI
10.1121/1.2934446
Abstract
A simple classroom demonstration consists of a weather balloon filled with carbon dioxide, a sound source, and a microphone. Since the speed of sound is slower in carbon dioxide than in air at room temperature and pressure, the balloon acts as a positive spherical acoustic lens. The accuracy of ray methods in locating the acoustic focus versus a full blown wave solution approach is probed. This problem presents particular difficulties if the sound source lies in the near field region. The sound emitter is treated as a dipole source equivalent to a rigid oscillating sphere of small size and amplitude of motion relative to the scatterer. The energy flux around the balloon is visualized by both ray methods and by the acoustic Poynting vector field. The geometrical ray results and the acoustic Poynting vector field resulting from the wave solution are compared. © 2008 Acoustical Society of America
Recommended Citation
Dean, Cleon, James P. Braselton.
2008.
"The Energy Flow For A Spherical Acoustic Lens: Ray vs. Wave Methods."
The Journal of the Acoustical Society of America, 123: 3520: Acoustical Society of America.
doi: 10.1121/1.2934446
https://digitalcommons.georgiasouthern.edu/physics-facpubs/6
Comments
Copyright 2008 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.