Systematic Optimization of an Exhaust System to Meet Noise Radiation Criteria at Idle
2014 (English)In: SAE International Journal of Passenger Cars - Mechanical Systems, ISSN 1946-3995, Vol. 7, no 3Article in journal (Refereed) Published
Exhaust noise is a major contributor to the radiated noise level of a vehicle, especially at idle. The radiated noise level has to meet a certain criteria based on regulation and consumer demand. In many cases, the problem appears after the vehicle is manufactured and the tailpipe noise measurement is performed indicating a high noise level that needs to be reduced. This paper describes one of those cases where the radiated noise level of a certain passenger car at idle was required to be reduced by 6 dB(A). The exhaust system consists of one main muffler and one auxiliary muffler. A 1D two-port model of the exhaust system including the two mufflers was built using commercial software. This model was validated against the measurement of the two-port matrix of both mufflers. The model was then used together with tailpipe noise measurements to estimate the characteristics of the source strength and impedance. Using a 1D model of the complete system, it was possible to propose several modifications for the vehicle manufacturer to choose from. A systematic optimization approach is presented in this paper describing several suggestions to reduce the radiated tailpipe noise.
Place, publisher, year, edition, pages
2014. Vol. 7, no 3
Acoustic noise measurement, Automobile manufacture, Commercial software, Consumer demands, High noise levels, Noise measurements, Noise radiations, Systematic optimization, Two-port models, Vehicle manufacturers
IdentifiersURN: urn:nbn:se:kth:diva-161537DOI: 10.4271/2014-01-0006ScopusID: 2-s2.0-84903398827OAI: oai:DiVA.org:kth-161537DiVA: diva2:794661
QC 201503122015-03-122015-03-122015-03-12Bibliographically approved