无人机用点燃式二冲程柴油机燃烧特性研究  

Combustion characteristics of a two-stroke spark-ignition diesel engine for UAVs

作　　者：陈依涵 赵振峰[1] 王斌[2] 贺金虎 庞英 CHEN Yihan;ZHAO Zhenfeng;WANG Bin;HE Jinhu;PANG Ying(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China;Technology Department,Northern General Dynamics Group Co.Ltd,China North Industries Group Co.Ltd,Datong 037000,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]中国兵器工业集团山西柴油机工业有限责任公司工艺中心,山西大同037000

出　　处：《推进技术》2024年第7期144-152,共9页Journal of Propulsion Technology

基　　金：基础产品创新计划(DEDP-145DRCD)。

摘　　要：针对柴油燃料雾化蒸发困难导致的发动机燃烧效果差、易爆震的问题,本文采用空气辅助缸内直喷方案,对一台点燃式二冲程柴油发动机开展燃烧特性研究。建立了点燃式二冲程柴油发动机的三维仿真模型,对混合气特性和燃烧特性进行仿真研究,并通过台架试验进行了验证。研究结果表明:点燃式二冲程柴油发动机在热机工况下,点火时刻有58%的燃油蒸发,缸内平均当量比由冷起动工况下的0.2提升至0.8,混合气品质较高,缸内燃烧情况良好。通过燃用汽油、柴油两种燃料进行发动机整机性能对比试验发现,在高转速大负荷工况下,两种燃料的燃烧特性曲线十分接近,柴油燃烧的指示平均有效压力(IMEP)的分布均值仅比汽油低1.2%。总体而言,柴油燃料应用于点燃式二冲程发动机的燃烧性能与汽油燃料相似,且使用柴油燃料时缸内压力最大震荡幅值仅为0.02 MPa,远小于爆震阈值,不会出现爆震现象。To address the problems of poor combustion and knock caused by the difficulty of diesel fuel at-omization and evaporation,the combustion characteristics of a two-stroke spark-ignition diesel engine has been investigated by adopting the air-assisted direct injection scheme.A three-dimensional simulation model of the two-stroke spark-ignition diesel engine is established,and the mixture characteristics and combustion character-istics are simulated and verified through bench tests.The results show that under hot engine conditions,58%of the fuel evaporates at the ignition time,the average equivalent ratio of the cylinder increases from 0.2 to 0.8 com-pared with cold starting conditions,the quality of the mixture is high,and the in-cylinder combustion is excel-lent.Through the comparison test of engine performance with gasoline and diesel,it is found that under high speed and large load conditions,the combustion characteristic curves of the two fuels are extremely close,and the average distribution of indicated mean effective pressure(IMEP)for diesel combustion is only 1.2%lower than that for gasoline.In general,the combustion performance of diesel used in the two-stroke spark-ignition en-gine is similar to that of gasoline,and when using diesel,the maximum oscillation amplitude of the cylinder pres-sure is only 0.02 MPa,which is much lower than the knocking threshold,so there will be no knocking phenome-non occurs.

关 键 词：点燃式柴油机 直喷 空气辅助喷射 燃烧特性 仿真 

分 类 号：V234[航空宇航科学与技术—航空宇航推进理论与工程]