柴油机主要振源循环平稳特性实验

Cyclostationary Characteristic of Main Vibration Sources of Diesel

在循环平稳理论的基础上讨论了柴油机振源循环平稳特性的分析方法,分析了柴油机激励源信号具有循环平稳特性的原因并用仿真信号进行了验证。从柴油机的特性出发设计测量气阀撞击激励源和活塞-缸套撞击激励源的实验,通过实测得到气阀应变和活塞应变,结合理论分析与实验结果计算得到激励源的循环平稳特性。结果表明,柴油机激励源信号的循环频率为转频的半倍频。

Diesel excitation signal and vibration acceleration signal have intricate non-stationary characteristics, and the characteristics of these excitation sources have important significance to fault recognition and condition monitoring. Research on the characteristics of these excitation sources is the base for other further studies. Based on the theory of cyclostationarity, the analysis method for diesel excitation sources cyclostationarity is discussed; then the reason of diesel excitation sources exhibited cyclostationarity is analyzed and validated by simulation signal; the experiment for measuring excitation sources of valve slap and piston knock from the characteristic of diesel is designed and the strain of valve and piston are got by the experiment; at last, the cyclostationarity of excitation sources is got through the theory analysis and experiment result calculation. The result indicates that the cycle frequency of the diesel excitation sources is the half frequency multiplication of rotation frequency.