【摘要】 分析比较了火花点火发动机循环变动的评价方法 ,并提出了用各个曲轴转角下的压力变动率曲线表示压力循环变动的方法。结果表明 ,平均指示压力的标准差及变动率是评定内燃机压力循环变动的最佳参数 ;各个曲轴下的压力标准差及变动率曲线可以清楚地表示出发动机工作过程中各个曲轴转角下的压力变动情况 ;进气过程中也存在压力变动 ,其压力变动率高于燃烧过程 ;燃烧过程的压力变动率存在一个峰值更多还原

【Abstract】 The methods of evaluation on pressure cyclic variation in a spark ignition engine are studied in this paper.The results show that standard deviation and coefficient of variation of indicated mean effective pressure are the best parameters.The situation of pressure cyclic variation can clearly express with the circumstance of standard deviation and coefficient of pressure cyclic variation at each crank angle.There is a peak value of coefficient of pressure cyclic variation in combustion process.Pressure cyclic variation begins from intake process.更多还原