This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Boundary Element Energy Method for the Acoustic Prediction of External and Interior Vehicle Noise - Application on a Truck
Technical Paper
2010-01-1406
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
In the context of more and more drastic noise regulation and increasing customers demand for lower noise annoyance, acoustic shields become essential for a wide range of vehicles. Due to reduced development time, acoustic design must start in the early stage of industrial projects, requiring precise and reactive prediction tools. The most widely used computation methods perform a numerical resolution of Helmholtz equation with a spatial discretization into Finite Elements or Boundary Elements. These methods are efficient in the low frequency range, but they reach their limits at higher frequencies, due to high computational cost, very precise mesh required, and high sensitivity to geometry and frequency. Then Ray Tracing techniques may be an alternative in some cases, but diffused reflection is generally ignored and convergence is not always reached, observation points receiving too few rays. The method proposed here is also based on a light/sound analogy, but the resolution is based on Boundary Elements. Lamberts law is used to model diffuse reflection. Absorbing materials are characterized by diffuse absorption coefficients, widely used in the industry. The frequency based meshing criterion is relaxed: only the description of the geometry must be considered. The resolution can be made every third-octave if the evolution of acoustic properties is smooth enough. The phase information is not kept. Meshing and computation time are drastically reduced. This energy method is dedicated to industrial acoustic issues in the mid and high frequency range, preferably with complex geometries, broadband and distributed sources. The method is therefore particularly suited for the prediction of the noise radiation of thermal engine in its environment. The acoustic resolution is carried out by a specific program and relies on view factors computed with thermal radiation software. Successful comparisons with measurements are presented, concerning the engine compartment of trucks. Successful comparisons with measurements are presented, concerning both external and internal noise predictions for trucks.
Recommended Content
Journal Article | Localization of Truck Noise Sources under Passby Conditions Using Acoustic Beamforming Methods |
Technical Paper | Materials for Noise Control |
Technical Paper | Virtual Transfer Path Analysis at Daimler Trucks |
Authors
Citation
Thivant, M., Bouvet, P., Cloix, A., Blairon, N. et al., "Boundary Element Energy Method for the Acoustic Prediction of External and Interior Vehicle Noise - Application on a Truck," SAE Technical Paper 2010-01-1406, 2010, https://doi.org/10.4271/2010-01-1406.Also In
References
- Thivant M. Bouvet P. Cloix A. Blairon N. Boundary Element Energy Method for the acoustic design of vehicles shields Proceeding of ISNVH congress SAE Graz 2008
- Blairon N. Thivant M. Simulation du bruit des véhicules industriels lors de la certification européenne (Pass-by noise) Proceeding of 3rd congress SIA on Vehicle Comfort Le Mans 2004
- Thivant M. Modélisation de la propagation acoustique par la méthode du potentiel d'intensité Institut National des Sciences Appliquées 128 Lyon 2003
- Bouvet S. Méthode PIANO, livre technique VIBRATEC 900.446.LT13.C 2004
- Augis E. Mesures sur une maquette d'encapsulage de véhicule industriel suivant une méthodologie de Type piano Rapport VIBRATEC n° 039.090.RA.01.A. 2000
- Thivant M. Cloix A. Boundary Element Energy Method for the prediction of machinery encapsulation Proceedings of SAPEM conference 2005
- Le Bot A. A vibroacoustic model for high frequency analysis Journal of sound and vibration 211 4 537 554 1998
- Le Bot A. Bocquillet A. Comparison of an integral equation on energy and the ray tracing technique for room acoustics JASA 108 4 1732 1740 2000
- Le Bot A. Reboul E. Perret-Liaudet J. Introduction of acoustical diffraction in the radiative transfer method Comptes rendus mécanique 332 7 505 511 2004
- Le Bot A. Reboul E. Niveau sonore à 7.5m d'un GMP par le code CERES LTDS UMR CNRS 5513 10 2005
- Lambert R.F. Beranek L. Sound in large enclosures Noise Reduction 222 245 USA 1991