关键词: 单缸熄火, 噪声源, 小波时频分析, 激励源响应

Abstract:

In the study of identification of noise source and its excitation source response of V-cylinder diesel engine. A technique of JWSmICA based on fourth-order cumulants was set up. Firstly, the technique made use of single cylinder misfire method to separate mechanical noise and combustion noise in different running speeds and loads, the main noise source of V-cylinder diesel engine was found out, secondly, it combined joint approximate diagonalization of eigen-matrices(JADE) algorithm based on fourth-order cumulants with wavelet time-frequency analysis to separate and identify major excitation source response of noise source under the same conditions. Combining single cylinder misfire with independent component analysis(ICA) identification analysis results, it was found that mechanical excitation including the valve impact and piston-slap, and combustion excitation. The technical analysis was applied to draw the conclusion, which will be a key point of noise reduction to restrain the vibration energy in low and medium frequency range of combustion excitation source response.

Key words: single cylinder misfire, noise source, wavelet time-frequency analysis, excitation source response