This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Computational and Experimental Evaluation of a Hybrid Muffler
Technical Paper
2014-36-0782
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Currently, the Brazilian fleet is estimated at 40.0 million automotive vehicles. In the urban centers, as a consequence of this fact, the humans are being exposed daily to continuous and intermittent unwanted noises emitted by these vehicles. The prolonged exposure to noise can cause irreversible damage to human health. As a general rule, the automotive noises are low frequency and the mufflers used to attenuate these noises are made by uniting several kinds of acoustic filters. There are two types of acoustic filters: reactive and dissipative. The first type is made by the expansion chambers, resonators, labyrinths, perforated tubes and other types, by the addition of absorbent material to its inner part. The absorbent materials are fibrous and they have the purpose of increasing the efficiency of acoustic filters. The mufflers built with these two types of filters are called hybrids. There are many works that involve purely reactive mufflers without absorbent material. However, there are few studies that depict the acoustic behavior of mufflers with absorbent material. The difficulty in studying this type of filter is to characterize the acoustic properties of the absorbing material. The properties required for the evaluation of dissipative mufflers are: characteristic acoustic impedance and complex wave number of the traveling wave. This work evaluates the efficiency of a hybrid muffler with the Finite Element Method in terms of its sound transmission loss. The absorbent material is characterized by an inverse methodology. The computational results are compared with an experimental analysis and show a good agreement.
Authors
Topic
Citation
Lima, K., Pimental, V., Barbieri, N., Barbieri, R. et al., "Computational and Experimental Evaluation of a Hybrid Muffler," SAE Technical Paper 2014-36-0782, 2014, https://doi.org/10.4271/2014-36-0782.Also In
References
- Lee , I. Acoustic characteristics of perforated dissipative and hybrid silencers PhD Thesis The Ohio State University USA 2005
- Lee , I. J. , Selamet , A. and Huff , N. T. Acoustic impedance of perforations in contact with fibrous material Journal of Acoustical Society of America 119 5 2785 1797 2006 10.1121/1.2188354
- Lee , I. J. and Selamet , A. Impact of perforation impedance on the transmission loss of reactive and dissipative silencers Journal of Acoustical Society of America 120 6 3706 3713 2006 10.1121/1.2359703
- Storn P. and Price , K. Differential Evolution: a simple and efficient adaptive scheme for global optimization over continuous spaces International Computer Science Institute , Technical Report TR-95-012 Berkeley 1995
- Wu , T. W. and Wan , G. C. Mufflers performance studies using a direct mixed-body boundary element method and a three-point method for evaluating transmission loss Transactions of The ASME - Journal of Vibration and Acoustics 118 479 484 1996 10.1115/1.2888209
- Antebas , A. G. , Denia , F. D. , Pedrosa , A. M. and Fuenmayor , F. J. A finite element approach for the acoustic modeling of perforated dissipative mufflers with non-homogeneous properties Mathematical and Computer Modelling 57 7-8 1970 1978 2012 10.1016/j.mcm.2012.01.021
- Tao , Z. and Seybert , A. F. A Review of Current Techniques for Measuring Muffler Transmission Loss SAE Technical Paper 2003-01-1653
- Lima , K. F. , Barbieri , R. and Barbieri , N. Evaluation of three methods for parametric optimization of the shape of the cylindrical surface of a tube used in acoustic filters Noise Control Engineering Journal 61 6 10.3397/1/3761046
- Delany , M.E. and Bazley , E. N. Acoustical properties of fibrous absorbent materials Applied Acoustics 3 105 116 1970