喷孔结构对多孔GDI喷油器喷雾特性的影响  

Influence of Nozzle Configuration on Spray Characteristics of Multi-Hole GDI Injector

作　　者：程强[1] 张振东[1] 谢乃流[1] 朱希[1] 

机构地区：[1]上海理工大学机械工程学院,上海200093

出　　处：《内燃机学报》2014年第1期45-51,共7页Transactions of Csice

基　　金：国家自然科学基金资助项目(51275309);上海市教委科研创新资助项目(13YZ110);上海市研究生创新基金资助项目(JWCXSL1201)

摘　　要：喷孔结构直接决定多孔非对称缸内直喷汽油(GDI)喷油器的孔内流动状态,进而影响GDI喷油器的雾化特性.建立了不同喷孔内圆倒角、喷孔长径比和喷孔锥角等几何参数模型,并结合CFD仿真、高速摄影和激光测量技术对不同喷孔参数的空穴现象、喷雾形态、贯穿距离和索特平均直径的概率密度等进行了研究.结果表明:喷孔内圆倒角有利于减弱空穴现象,增加贯穿距离,但油雾的索特平均直径增大;喷孔长径比对于空穴现象的影响不明显,对贯穿距离和平均索特粒径的影响并不遵循线性规律;喷孔锥角对空穴现象的影响较小,喷雾贯穿距离随着喷孔锥角的增加而减小,但每一束油束锥角变大,喷雾范围扩大,雾化质量提高.Nozzle configuration directly determines the flow state in multi-hole non axisymmetric GDI injector, thereby affecting its atomization characteristics. A model for different inner circle chamfering, length-diameter ratio and spray cone angles of the nozzles were established. The EDM （electro-discharge machining） and abrasive flow technology were used to process the nozzle samples. CFD simulation, high- speed photography and laser measurement were used to analyze and validate the effects of different nozzle parameters on spray pattern, penetration distance and probability density of sauter mean diameter. Results show that, inner chamfering of nozzle effectively decrease the cavitation of nozzle inner flow and increase penetration distance, while sauter mean diameter of spray is slightly increased. The length-diameter ratio of nozzle impact on cavitation is unobvious, and the effect on penetration and sauter mean diameter does not follow a linear law. The nozzle cone angle impact on cavitation is also unobvious. Spray penetration distance is decreased with increase of nozzle cone angle, but individual spray cone angle is increased, leading to the improvement of atomization.

关 键 词：缸内直喷汽油喷油器 喷孔结构 流动特性 喷雾形态 

分 类 号：TK412[动力工程及工程热物理—动力机械及工程]