通过改变燃烧室结构和压力脉冲的大小 ,测量压力脉冲和噪声信号 ,求取燃烧噪声传递函数 ,并对不同方法求取的传递函数进行比较分析。设计适当的时间窗获取正常工况下的活塞拍击噪声和燃烧噪声 ,并与用传递函数和测量的缸内燃烧压力计算所得的燃烧噪声进行比较分析 ,对活塞拍击特性进行了分析 ,为燃烧噪声的机理研究提供了较好的方法 By changing the structure of the combustion chamber and the size of the pressure pulse, the pressure pulse and the noise signal are measured to obtain the combustion noise transfer function. The transfer functions obtained by different methods are compared and analyzed. An appropriate time window is designed to obtain the rattling noise and combustion noise of the piston under normal conditions and the comparative analysis of the combustion noise calculated by the transfer function and the measured combustion pressure in the cylinder is carried out to analyze the characteristics of the piston slamming. The mechanism of combustion noise provides a better method