Research Of Engine Noise Testing And Analysis

With the development of industry and transportation, engine's noise and vibration has become more critical. Noise index is an important aspect in evaluating engine's performance. Analysis and control of engine noise has the significance. The main contents of this paper as follow:Fundamental theories about vibration and noise especially precedential research on engine noise are summarized. On the basis of analyzing engine's structure and working principle, the origination, transfer path, influential factors and control measures of engine noise are analyzed in this paper; With regard to noise testing, sound pressure and sound intensity are introduced. Traditional sound pressure c an b e affected b y environment e asily, how to select proper instrument and improve testing precision are discussed in this paper. Study of sound intensity is focused on testing principal, instrument structure, instruction and how to reduce error. The works will be helpful for the further noise studying through sound intensity; Application of signal processing technology particularly frequency spectrum, power spectrum and wavelet analysis in noise research are studied, some methods of noise source identification are also discussed. The testing object in this paper is an engine (6 cylinders),aimed at evaluating and improving its noise performance, sound pressure is measured inanechoic chamber, hence sound power determined, frequency spectrum is also analyzed andthe main source and cause identified.