摘要
在一台低压空气辅助直喷活塞式航空发动机上进行试验,分析了不同喷射开始时刻、点火提前角、过量空气系数对活塞式航空煤油直喷发动机燃烧特性的影响,并对比了航空煤油与汽油在混合气形成、滞燃期、火焰传播速度、抗爆性等方面的差异.研究表明:存在一个最佳喷射开始时刻使得燃油雾化质量最好,循环变动率最小,航空煤油冷起动比汽油困难.航空煤油火焰传播速度比汽油慢,同工况下航空煤油最佳点火提前角大于汽油,偏离最佳点火提前角对航空煤油热效率的影响大于汽油.航空煤油比汽油更加适合在燃油摩尔分数较大的混合气下燃烧,在过量空气系数为0.80~0.85的范围内,航空煤油的滞燃期最短,燃烧循环变动率最小.在低速大负荷工况下,航空煤油爆震强度显著上升,抗爆性比汽油差.
Based on the experiment implemented on a low pressure air-assistant direct injection piston aviation engine,the influence of different start of injection timings,advance ignition angles,excess air ratios on the combustion characteristics was analyzed,and the difference between aviation kerosene and gasoline in the aspect of mixture formation,ignition delay period,flame propagation velocity and anti-detonating quality was compared.The result shows that：the fuel atomization will get higher and the cyclic variation coefficient get lower at the optimal start of injection timing,the cold start for aviation kerosene is harder than gasoline.Aviation kerosene＇s optimal advance ignition angle is bigger than gasoline＇s under same conditions since its flame propagation velocity is lower than gasoline,and the impact of thermal efficiency on aviation kerosene is more obvious than on gasoline when the optimal advance ignition angle is deviated from the minimum advance for the best torque.Compared with gasoline,aviation kerosene is more suitable for burning in the enviroment with biger fuel mole fraction,when the excess air ratio is with in the range of 0.80 to 0.85,the ignition delay period of aviation kerosene will be the shortest and the cyclic variation coefficient will be the lowest.Under the low speed and high load condition,the knock intensity gets higher significantly.The anti-detonating quality of aviation kerosene is worse than gasoline.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2017年第5期1035-1042,共8页
Journal of Aerospace Power
基金
国家自然科学基金(51476112)
天津市科技计划(13ZCZDGX04400)
关键词
活塞式航空发动机
航空煤油
汽油
燃烧特性
抗爆性
piston aviation engine
aviation kerosene
gasoline
combustion characteristic
anti-detonating quality
