直喷式柴油机火焰浮起不对称性的数值模拟  

Numerical Simulation of Flame Lift-off Asymmetry in DI Diesel Engine

作　　者：杨俊伟[1] 赵昌普[2] 孙强[2] 白曼[2] 李艳丽[2] 

机构地区：[1]奇瑞汽车股份有限公司发动机工程研究院,芜湖241009 [2]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2014年第5期445-452,共8页Journal of Combustion Science and Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA111705);国家自然科学基金资助项目(50676067)

摘　　要：为了合理评价直喷式柴油机湍流扩散燃烧火焰浮起的不对称性,建立了一个新的评价体系.该评价体系包括一个评价平面系、度量标准以及若干特征参数的定义,并在该评价体系内以数值模拟的方式研究了直喷式柴油机湍流扩散燃烧火焰浮起不对称性的相关问题.在所建CFD三维数值分析模型的有效性得到相关试验数据的验证后,采用验证后的模型分别研究了火焰浮起不对称性的各表征参数随时间发展、贴壁程度和涡流转速的变化趋势.分析结果表明,喷油油束的贴壁程度以及缸内的涡流转速是产生火焰浮起不对称性的主要原因.该研究为采取有效措施调控火焰浮起长度、降低柴油机碳烟排放奠定了基础.To reasonably evaluate the turbulent diffusion flame lift-off asymmetry in DI diesel engines,an evaluation system was established. This evaluation system consists of a coordinate system,a measurement criterion and definitions of some characteristic parameters. The turbulent diffusion flame lift-off asymmetry and some related problems in a DI diesel engine were studied with this evaluation system. After the model＇s validity was proved,the developments of the flame lift-off asymmetry characteristic parameters along with time scale,surface proximation and swirl speed were respectively investigated. The results indicate that the fuel sprays＇ proximation to the wall and the swirl rotational speed are the key factors inducing flame lift-off asymmetry in DI engines,which lays foundation for effective control of flame lift-off length and decrease of soot emission.

关 键 词：柴油机 火焰浮起 不对称性 数值模拟 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]