缸盖振动加速度信号与燃烧过程时域相关性分析

Time-Domain Analysis of Relationship between Engine Cylinder Head Vibration Acceleration and Combustion Process

对缸盖位移与缸内压力信号,缸盖振动加速度与缸内压力升高加速度信号进行了对比分析,结果表明:燃烧峰值压力出现时刻前,缸盖位移及缸内压力信号变化趋势相近,缸盖振动加速度与压力升高加速度的特征点出现时刻接近。对比缸内压力信号及其压升率、压力升高加速度曲线可知:压力升高加速度曲线上存在特征点,分别与燃烧起始时刻、最大压升率出现时刻及峰值压力出现时刻等燃烧特征点接近。据此,提出了利用振动加速度信号的特征点对燃烧特征点进行估计的方法,并在ZH195单缸柴油机和495T柴油机上进行试验,试验结果表明了所提出的方法的可行性。

The cylinder head displacement and vibration acceleration were respectively contrasted with the cylinder pressure signal and its rise acceleration signal in time domain. It is found that before the peak cylinder pressure occurring, the trend of the cylinder head displacement and the cylinder pressure signal are almost same, and the appearance timings of feature points of vibration acceleration and the pressure rise ac- celeration are very close. From comparison of the cylinder pressure, its rise rate and acceleration curves, it is found that the feature points on the pressure rise acceleration curve are nearly corresponding to the moments of combustion feature points e.g. the points of combustion start, the max. pressure rise rate, and the peak cylinder pressure, etc. Accordingly, the method to estimate the combustion process feature points from the feature points of cylinder head vibration acceleration signals was proposed. The method had been verified in model ZH195 single cylinder and model 495T diesel engines successfully.