稀薄环境自燃与压力振荡关系的实验研究  

Experimental Study of Relationship Between Auto-ignition and Pressure Oscillation in the Lean Mixture

作　　者：范钦灏 齐运亮[1] 王志[1] FAN Qin-Hao;QI Yun-Liang;WANG Zhi(State Key Laboratory of Automotive Safety and Energy, Beijing 100084, China)

机构地区：[1]清华大学汽车节能与安全国家重点实验室

出　　处：《工程热物理学报》2019年第10期2440-2446,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.91541206);汽车安全与节能国家重点实验室自主课题(No.ZZ2019-031)

摘　　要：利用快速压缩机光学诊断,研究了压缩着火和火花点火辅助压缩着火方式下,当量比为0.4的异辛烷混合气的自燃特征与相应的爆震强度。通过分析燃烧过程图像和压力振荡特征讨论了混合气自燃与产生压力振荡的关系。结果表明:在有效温度为730~830 K的低压区,混合气自燃与压力振荡解耦;相近工况条件下,火花点火辅助压缩着火能够大幅缩短滞燃期并增加爆震强度;有效温度大于850 K时,"爆而不震"区域消失,但爆震强度对热力状态不敏感。Auto-ignition behavior and knock intensity were investigated in iso-octane/buffer gas mixture with and without spark through an optical rapid compression machine.The equivalence ratio was fixed at 0.4.Images of combustion process combined with characteristics of pressure oscillation were discussed.The results show that in low pressure areas where effective temperature ranges from 730~830 K,auto-ignition is decoupled with pressure oscillation.In the similar thermodynamic conditions mentioned above spark assist can greatly shorten ignition delay and increase knock intensity.With temperature over 850 K non-knock area disappear while knock intensity is insensitive to thermodynamic conditions.

关 键 词：自燃 压力振荡 爆震强度 空气稀释 快速压缩机 

分 类 号：TK16[动力工程及工程热物理—热能工程]