GDI椭圆喷孔的喷雾撞壁特性  

Spray-wall impingement characteristics of GDI elliptical nozzle

作　　者：王葭泽 贾和坤[1] 俞升浩 周泽原 WANG Jiaze;JIA Hekun;YU Shenghao;ZHOU Zeyuan(School of Automotive and Traffic Engineering,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2023年第1期96-103,111,共9页Journal of Jiangsu University：Natural Science Edition

基　　金：江苏省自然科学基金资助项目(BK20201166)。

摘　　要：采用流体体积-喷雾单向耦合(VOF-spray one way coupling)分析方法,在不同喷射压力下对缸内直喷汽油机(GDI)圆形和椭圆喷孔的内部流通特性和喷雾撞壁特性进行了模拟仿真研究.结果表明:同等压力条件下,椭圆喷孔出口处异辛烷质量流量大于圆形喷孔,当喷射压力为15.0 MPa时,椭圆喷孔长短轴比为4的椭圆喷孔E2中异辛烷质量流量要比圆形喷孔大3.54%;在喷雾贯穿阶段,由于椭圆喷雾贯穿距离始终小于圆形喷雾,导致椭圆喷雾撞击壁面的时间延迟,当喷射压力为6.0 MPa时,椭圆喷孔E2的喷雾撞壁时间较圆形喷雾推迟0.14 ms;喷雾撞击壁面后,圆形喷雾的铺展半径和卷吸高度都要大于椭圆喷雾,这是因为圆形喷雾速度快,喷雾动量大,促进了喷雾的飞溅和反弹,但这种差异随着喷射压力的提高而减小.The internal flow and spray-wall impingement characteristics of circular and elliptical GDI orifices were simulated by the VOF-spray one way coupling method under different injection pressures. The results show that the mass flow rate of isooctane at the outlet of elliptical orifice is larger than that of circular orifice, and the mass flow rate of isooctane in elliptical orifice E2 with the aspect ratio of 4 is 3.54% larger than that of circular orifice under the injection pressure of 15.0 MPa. In the spray penetration stage, the spray penetration of elliptical orifice is always smaller than that of circular orifice, which delays the time when the spray impacts the wall. Under the injection pressure of 6.0 MPa, compared with the circular orifice, the spray impingement time of the elliptical orifice E2 is delayed by 0.14 ms. The impinged spray radius width and height width of the circular orifice are larger than those of the elliptical orifices after the impingement. This is because the circular spray has larger momentum, which promotes the splash and rebound of the impinged spray, while the difference between circular and elliptical orifices is decreased with the increasing of injection pressure.

关 键 词：内燃机 汽油直喷 椭圆喷孔 流通特性 喷雾撞壁特性 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]