摘要
使用平面激光诱导荧光法(PLIF)对缸内直喷液化石油气(LPG)混合气分布进行了定量研究。测试结果表明,在点火时刻压缩冲程喷射形成分层混合气,其浓区处于火花塞附近,且60℃A BTDC喷射形成的混合气分层效果优于90℃A BTDC喷射,而进气冲程(290℃A BTDC)喷射形成了较均匀的混合气。60℃A BTDC喷射形成的混合气浓区集中难以扩散,浓区位置受涡流运动影响较大,而90℃A BTDC喷射的混合气分布未见明显的集中浓区,在30℃A BTDC后形成较均匀的混合气。在统计区域内,60℃A BTDC喷射形成的混合气循环变动低于90℃A BTDC和290℃A BTDC喷射的循环变动。
Mixture distribution in the cylinder of a LPG engine was quantitatively measured by using PLIF in direct injection mode. The results show that the injection in the compression stroke forms a stratified mixture with high concentration near the spark plug at the ignition timing. Injection at 60°CA BTDC has better effect in stratification than injection at 90°CA BTDC. Injection at 290°CA BTDC only forms the homogenous mixture. High concentration aera formed by injection at 60°CA BTDC is largely influenced by swirl and is difficult to diffuse. There is no distinct rich area when the injection starts at 90°CA BTDC and relative homogenous mixture appears after 30°CA BTDC. In the calculation area around the spark plug＇s pole, mixture formed by injection at 60°CA BTDC shows lower cycle variations than the cases that injection starts at 90°CA BTDC or 290°CA BTDC
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2009年第6期481-486,共6页
Transactions of Csice
基金
国家自然科学基金(50576047)
山东省自然科学基金(Y2006F02)
