直喷汽油喷油器喷射过程近场喷雾特性  

Near-Field Characterization of Direct Injection Gasoline Sprays from a Single-Hole Injector

作　　者：何邦全[1] 张倓恺[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机学报》2013年第5期425-430,共6页Transactions of Csice

基　　金：国家高技术研究发展计划"863"资助项目(2006AA110107)

摘　　要：利用长距显微镜和高速摄影相结合的方法,研究了单孔直喷汽油喷油器喷孔下方1.5,mm内的近场喷雾特性.结果表明,在喷油过程中,近场喷雾锥角经历了骤减、大幅波动、波动衰减和结束缓增4个阶段.提高喷油压力差能够明显增强喷雾的初次破碎.在相同的喷油压差下,随着喷油背压的增加,喷雾形成初期的轴向速度降低.喷油压力差对喷雾形成初期的轴向速度影响较大.在喷油结束阶段,在喷孔处会形成膜状油束,最后破碎成较大的油滴.The spray characteristics within 1.5 mm below its hole exit of a direct injection single-hole gasoline injector were investigated through a long-distance microscope and a high-speed digital camera. The results show that the development of spray cone angle experiences a sharp decrease, intensive fluctuation, slight fluctuation and gradual rise versus the time. The increase in the difference between fuel pressure and back pressure enhances the primary break-up. The velocity of spray declines with increased back pressure in the constant vessel at fixed injection pressure differences. The difference between fuel pressure and back pressure evidently affects the vertical velocity of spray at the beginning of fuel injection. Fuel film is formed at the injector hole exit at the end stage of injection and is finally broken up into the droplets with large diameter.

关 键 词：汽油 喷油器 近场 喷雾 空化数 

分 类 号：TK417.4[动力工程及工程热物理—动力机械及工程]