射流角度对双燃料发动机燃烧过程的影响  

Effect of Jet Angles on Combustion Process of a Dual Fuel Engine

作　　者：陈贵升[1] 魏峰 杨杰[1] 黄震 张敬贤 张涵[1] Chen Guisheng;Wei Feng;Yang Jie;Huang Zhen;Zhang Jingxian;Zhang Han(Yunnan Key Laboratory of Internal Combustion Engine,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学云南省内燃机重点实验室,云南昆明650500

出　　处：《内燃机学报》2022年第4期297-305,共9页Transactions of Csice

基　　金：国家自然科学基金资助项目(51866004);云南省教育厅科学研究基金资助项目(2022Y157).

摘　　要：基于三维流体力学软件,模拟研究了天然气射流中心轴线与水平方向夹角α、柴油/天然气两射流的中心轴线在水平方向上相对交角β对柴油/天然气双直喷发动机缸内射流发展、混合及燃烧过程的影响,结果表明:水平夹角α较小(30°和40°)时,受燃烧室空间限制难以形成稳定的涡旋结构;α较大(50°和60°)时,有利于形成尺度较大且稳定的涡旋结构,与后续柴油射流作用后,形成较多柴油-天然气-空气混合气,引燃面积增大,燃烧速率加快且温度分布更加均匀,剩余未燃CH;较少;相对交角β较小(0°和10°)时,缸内混合气形成不均匀分布,燃烧室中心混合气较稀,唇口处较浓;β较大(30°和40°)时,柴油射流和原有涡旋相互作用,形成更多且分布更加广泛的柴油-天然气-空气混合气,缸内燃烧情况最好,剩余未燃CH;较少.Based on the three-dimensional fluid dynamics software,a simulation of angleα,which is the angle between the central axis of the natural gas jet and the horizontal direction,and angleβ,which is the relative intersection angle of the central axes of diesel-natural gas jets in the horizontal direction,was carried out to study jet development,mixing and combustion process in cylinder of a diesel-natural gas dual direct injection engine.Results show that when the horizontal angleαis small(30°,40°),it is difficult to form a stable vortex structure due to the limitation of the combustion chamber space.When the angleαis large(50°,60°),it is beneficial to form a large scale stable vortex structure.After the swirl structure interacts with the subsequent diesel jet,more dieselnatural gas-air mixtures are formed and the ignition area is increased.At the same time,the flame propagation speed increases and the temperature distribution becomes more uniform after burning.The larger angleαwill leave less unburned CH;in cylinder.Whenβis small(0°,10°),the mixtures in cylinder form uneven distribution.The mixture in the center of the combustion chamber is relatively thin,while the mixture in the lip is relatively thick.Whenβis large(30°,40°),the diesel jet interacts with the original vortex to form more and more widely distributed diesel-natural gas-air mixture.At large angleβ,the combustion is better,and less unburned CH;remains.

关 键 词：柴油 天然气 数值模拟 射流角度 燃烧过程 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]