SIMPLE ANALYSIS OF EXHAUST NOISE PRODUCED BY A FOUR CYLINDER ENGINE

Developing an idea of Laville and Soedel @J. Sound Vib., 60 (1978) 273@, the noise radiated by the exhaust system of a four cylinder engine is calculated, analytically and numerically, and compared to experiment. The basic idea is as follows: the effect of the exact shape of the volume velocity signal produced by a cylinder during opening can be considered as a second order effect on the result. The amplitude of every harmonic of the radiated noise is shown to be proportional to the first order of certain quantities, the zeroth order being zero. The analysis of the amplitude of the radiated noise exhibits the role of the resonances of the admittance of the whole exhaust as viewed from outside when the cylinders are closed, and of the resonances of the manifold. Comparisons with experiment confirms the basic hypothesis and the result of the theory, at least qualitatively, but losses seem to cancel the manifold resonances, which are related to the interferences between parallel tubes. (A)

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  • Corporate Authors:

    Elsevier Science Publishers

    Crown House, Linton Road
    Barking, Essex IG11 8JU,   England 
  • Authors:
    • DESMONS, L
    • KERGOMARD, J
  • Publication Date: 1994

Language

  • English

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Filing Info

  • Accession Number: 00662426
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Jul 28 1994 12:00AM