A Kirchhoff approximation-based numerical method to compute multiple acoustic scattering of a moving source
2015 (English)In: Applied Acoustics, ISSN 0003-682x, Vol. 96, 108-117 p.Article in journal (Refereed) Published
Within the scope of a study of external noise propagation from moving ground vehicles, a numerical method is developed to compute the acoustic field emitted by a moving source in the presence of scattering objects such as roads, buildings or noise-shields. This method is developed with the purpose of being used in a vehicle design process and therefore it must have a low computational cost, which requires a certain number of approximations. The case of a fixed point source is studied first then the effect of a movement of the source is taken into account through the introduction of a retarded time. The acoustic source is assumed to be represented by one or many harmonic monopoles of possibly different frequency moving with a constant speed in a quiescent flow field. Scattering from nearby perfectly reflecting objects is computed through a Kirchhoff–Helmholtz integral equation applying the Kirchhoff approximation. A ray-surface intersection algorithm to compute shadow areas is proposed. The method is validated against analytical solutions and experimental results for a fixed source, and against a higher-order finite difference time-domain method for the multiple scattering of a moving source. Results are good and show that this method can potentially be used to predict urban noise.
Place, publisher, year, edition, pages
Elsevier, 2015. Vol. 96, 108-117 p.
Multiple scattering, Moving source, Kirchhoff–Helmholtz integral, Kirchhoff approximation, Urban noise
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-163047DOI: 10.1016/j.apacoust.2015.03.016ISI: 000355033900013ScopusID: 2-s2.0-84926306952OAI: oai:DiVA.org:kth-163047DiVA: diva2:798494
QC 201504242015-03-262015-03-262015-10-02Bibliographically approved