This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Study of the Generation mechanism for Abnormal Exhaust Noise
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 01, 1987 by SAE International in United States
Annotation ability available
Based on experimental analysis, the generation mechanism of abnormal exhaust noise which is characterized by an intermittent high frequency aetallic sound, is clarified by bench testing of a FWD vehicle.
The noise is caused by large amplitude pressure waves (finite amplitude waves) in the exhaust pipe. They are amplified due to interference between reflected waves and subsequent waves from the engine, and are finally transformed into shock waves in the propagation process along the exhaust pipe, resulting in abnormal exhaust noise. By theoretical analysis of finite amplitude waves, the wave profile in the propagation process and the transition distance to the shock wave can be solved analytically where the assumptions of mass, momentum, and energy conservation are valid, until the moment of shock wave formation. The transition distance is a key parameter in analyzing the growth and existence of shock waves. This paper proposes a simulation method for estimating the transition distance which enables the generation of abnormal exhaust noise.
|Technical Paper||Shock Wave Development and Propagation in Automobile Exhaust Systems|
|Technical Paper||Modeling and Prediction of Engine-Radiated Noise of a Motorcycle|
CitationOkada, M., Abe, T., and Inaba, M., "Study of the Generation mechanism for Abnormal Exhaust Noise," SAE Technical Paper 871924, 1987, https://doi.org/10.4271/871924.
- Shapiro A.H. “The Dynamics and Thermodynamics of Compressible Fluid Flow-Volume 1” Ronald Press New York 1953
- Landau L.D. Lifshitz M.E. “Fluid Dynamics” Moscow 1954
- Lipmann H.W. Roshko A. “Elements of Gas Dynamics” Yoshioka Shoten 1957
- Kuratani K. et al. “The Chemical and Physical Properties of Shock Waves” Shokabo 1958
- Furuhama F. “Internal Combustion Engine Technology” Sangyo Tosho 1976
- Jones A.D. Brown G.L. “Determination of two-stroke engine exhaust noise by the sethod of characteristics” Journal of Sound and Vibration March 1982 305 327