活塞式航空煤油直喷发动机的爆震控制

Knocking control of direct injection piston-type aviation kerosene engine

针对过量空气系数、点火提前角、压缩比等影响因素,在一台自主研发的单缸试验机上,开展了活塞式航空煤油发动机爆震抑制方法以及相关影响因素的爆震敏感度分析的研究。结果表明:减小过量空气系数不能有效地抑制航空煤油爆震;推迟点火能够减小爆震强度,但减小点火提前角至爆震消除时,燃烧热效率和输出功率均损失10%~15%;降低压缩比可以有效抑制航空煤油爆震燃烧,但压缩比由9降至7时,输出功率出现了30%左右的显著损失。爆震敏感度分析表明,压缩比的变化对航空煤油爆震燃烧强度影响最大,而过量空气系数的爆震敏感度最小。

Focusing on knocking-influenced factors including excess air coefficient,spark advance angle and compression ratio,investigations on methods to suppress the knocking of piston-type aviation kerosene engine and sensitivity analysis of relevant factors were conducted on a self-developed engine.The results showed that the decrease of excess air coefficient cannot suppress the knocking of aviation kerosene effectively;retarding ignition timing can reduce knocking intensity,but if the spark advance angle was delayed till the knocking was eliminated,the combustion thermal efficiency and output power lost 10%-15%;reducing compression ratio turned out to be effective to restrain the knocking of aviation kerosene,but when compression ratio was reduced from 9 to 7,the output power had an approximate 30%loss.Sensitivity analysis shows that knocking intensity of aviation kerosene is most sensitive to the change of compression ratio,and the change of the excess air coefficient of mixture slightly influences the knocking intensity.