Research On Noise Source Identification Of Vehicles By Sound Intensity Measurement

This paper researches on a novel method to measure three-dimensional sound intensity use for failure diagnosis of electro-hydraulic system and the fabrication of a miniature three-dimensional sound intensity probe by using two separate micro-machined pressure probes and one microphone frame. A three-dimensional sound intensity probe has been realized based on a three-dimensional micro-machined pressure microphone, built into a miniature pressure microphone probe.Sound intensity describes the flow of acoustic energy produced by a sound source, and it is a vector. Sound intensity measurements accurately capture only the sound produced by the source under test, eliminating interference from other sounds and realizing the location of the sound.Traditional measurement of sound power and sound pressure must be processed under a rigorous acoustic environment and required that the device be shipped to an acoustical laboratory chamber. It is very difficult to realize under industrial circumstance, but the measurement of sound intensity can be processed. Sound intensity measurement allows accurate identification, isolation and ranking of individual sound sources. For complex machines and processes, the noisy components can be identified and treated. The measurement of sound intensity can be applied to course detect, product research and development applications.In this paper the measures of diagnosis analysis for noise sources have been discussed according to the sound intensity measurement. The sound intensity measurement is carried out for the exterior radiation noise of an automobile and by means of spectrum and correlation analysis of noise signal, an investigation into the application of sound intensity measurement to vehicle noise control is presented. For the main noise sources of automobile-noise of the engines made a distinguish analysis technology and various noise control measures. It isbeneficial reference to reduce noise of engine.