【摘要】 利用小波包分析提取缸内压力和测量噪声的时频信息,结合频谱分析技术,对缸内压力和测量噪声特性进行了研究.结合缸内压力和测量噪声的传递函数及相干分析,讨论了测量噪声各频带活塞拍击噪声和燃烧噪声的情况,并对缸内压力和燃烧噪声各频带所占能量进行了计算和研究.结果表明,通过缸内压力和噪声的时频及频谱分析,能获取更加详细的燃烧噪声和活塞拍击噪声信息,为燃烧噪声的分离以及机理研究提供了技术支撑.更多还原

【Abstract】 The time-frequency and spectrum analysis information is gained from the measurement of cylinder pressure and noise by the method of wavelet packet analysis. The characters of the cylinder pressure and noise are studied by the time-frequency and spectrum analysis. The situation of the piston slapping noise and combustion noise in each frequency range of the measured noise is discussed. The cylinder pressure and combustion noise’ energy in each frequency range is also calculated and analyzed. The results demonstrate that the high-frequency oscillation pressure has an important effect on combustion noise. Analyzing the cylinder pressure and noise by the time-frequency and spectrum analysis method can gain more information about the combustion noise and the piston slapping noise, and provide technical support for separating combustion noise and its principle research.更多还原