A coherent image source method for flat waveguides with locally reacting boundaries
Date of Issue2010
International Congress on Acoustics (20th : 2010 : Sydney, Australia)
School of Mechanical and Aerospace Engineering
An image source method is presented for coherently evaluating the sound field from a point source in flat waveguides with two infinite and parallel locally reacting boundaries, where one is sound absorbing and the other is reflective. The method starts from formulating sound reflections into integrals by plane wave expansion, and the inherent intractability in solving these integrals in such spaces is avoided by introducing a physically plausible assumption that wave fronts remain the same before and after the reflection on a near-rigid boundary. By comparisons to the classical wave theory and the existing coherent ray-based methods, it is shown that the proposed method is considerably accurate to predict the sound propagation in flat waveguides with a sound absorbing ceiling and a reflective floor over a broad frequency range and for various source/receiver geometries, even if at large distances from the source compared to the waveguide height while the existing methods are shown to be erroneous.
DRNTU::Science::Physics::Acoustics and sound
© 2010 Australian Acoustical Society. This paper was published in Proceedings of 20th International Congress on Acoustics, ICA 2010 and is made available as an electronic reprint (preprint) with permission of Australian Acoustical Society. The paper can be found at the following official URL: http://www.acoustics.asn.au/conference_proceedings/ICA2010/cdrom-ICA2010/papers/p386.pdf. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.