GDI喷油器喷嘴结构参数对喷雾特性影响分析

Analysis on Influence of Key Structure Parameters about Spray Characteristic of Injector in Gasoline Direct Injection System

从汽油直喷多孔喷油器喷嘴结构设计的角度出发,采用数值模拟的方法详细研究了喷嘴的关键结构参数对喷雾特性的影响,结果表明:在喷孔总流通截面积相同的情况下,增加喷孔数目,可以适当减小喷雾粒径和贯穿距离;喷孔均匀布置时的喷雾角度较小、贯穿距离较大;小孔形状为渐缩孔的贯穿距离最大,渐扩孔的贯穿距离最小,但渐扩孔的喷雾粒径相对较大;直孔和两级台阶孔的喷雾粒径较接近,两级台阶喷孔和三级台阶喷孔的喷雾贯穿距离和喷雾粒径均略低于直孔;孔径D1和D2对贯穿距离影响最大,其喷雾粒径主要受小孔直径D1影响;小孔长径比L/D1对贯穿距离也有一定的影响。

Based on the structure of nozzle in gasoline direct injection system, the influence of the key structure parameters on spray characteristics is studied in detail by the numerical simulation, results show that： in the same nozzle flow area, increasing the number of nozzle holes, can reduce the particle size and spray penetration ; When the arrangement of holes are uniform , the smaller spray an- gle, and larger spray penetration; holes shape of tapered hole in maximum distance, gradually expanding through the minimum dis- tance, but gradually expanding the spray particle size is relatively large ; the particle size of the straight hole and two step hole is close, the spray penetration and particle size of two step hole and three step hole were slightly lower than that of the straight hole, the pore di- ameter of D1 and D2 are maximum on the spray penetration, the droplet size is mainly affected by the pore diameter of D1, hole length diameter ratio of L/D1. Also has certain influent to the penetration distance.