Une Méthode Numérique pour Calculer la Diffusion Acoustique d’une Source Mobile par Plusieurs Objets
2014 (French)In: 12e Congrès Français d'Acoustique, 2014Conference paper (Other academic)
As part 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 point source and its interaction with a near environment constituted of buildings or noise barriers for example. This method is developed with the purpose of being used in a vehicle design process therefore it must be low demanding on computational resources. This requires approximations. The problem is simplified to that of a constant speed moving harmonic monopole point source passing by one or more perfectly reflecting large objects in a quiescent flow field. The simpler case of a fixed point source is studied first. Reflections on nearby objects are computed through a Kirchhoff-Helmholtz integral equation to which is applied the Kirchhoff approximation, assuming the regime of high frequencies. Multiple scattering is computed by consecutive updates of surface pressure values. The effect of a movement of the source is accounted for through the introduction of a Doppler shift in the Kirchhoff-Helmhotlz equation. This method is validated against experimental results from literature for a case of simple scattering of a sound wave emitted by a fixed source and against results from a higher-order finite difference time-domain solver in case of multiple scattering of the sound wave emitted by a moving point source. Results are satisfying for the foreseen use of this method.
Place, publisher, year, edition, pages
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-159512OAI: oai:DiVA.org:kth-159512DiVA: diva2:785404
CFA 2014 Poitiers, france, 22-24 April 2014
QC 201502052015-02-022015-02-022016-06-13Bibliographically approved