为了探究在超高喷射压力下GDI(gasoline direct injection)喷油器喷雾的宏观特性,采用阴影法对喷射压力为5~60 MPa 的喷雾进行测量,分析喷射压力对油束发展历程、贯穿距离、喷雾锥角、喷雾面积以及喷油器尾喷现象的影响,并通过对DENT经验公式进行修正,得到超高喷射压力下汽油的贯穿距离计算公式.研究结果表明:喷射压力的提高能够促进喷雾外围"分支状结构"的生成;喷射压力的提高使贯穿距离明显增大;喷雾面积随喷射压力的提高有所增加,但增幅逐渐减小;喷射压力每增加10 MPa,喷雾锥角峰值平均增加1.5°;当喷射压力达到30 MPa及以上时,喷油器尾喷现象基本消失;随着喷雾发展,贯穿距离和喷雾面积均呈现一定程度的线性增大;喷雾锥角呈先上升后下降,最后稳定在82°左右的趋势.%In order to explore the spray macroscopic characteristics of GDI(gasoline direct injection) injector under the ultra-high injection pressure, the spray under the injection pressures from 5 MPa to 60 MPa was measured by the shadow photographic method, and the effects of injection pressure on the spray development process, the spray penetration, the spray angle, the spray area and the post injection phenomenon were analyzed. The calculation formula of gasoline spray penetration under the ultra-high pressure was obtained by modifying the DENT empirical formula. The results show that the increase of injection pressure promotes the generation of "branch-like structure" on the outside of the spray. The increase of injection pressure increases the spray penetration obviously. As the injection pressure increases, the spray area increases, but its increasing rate decreases gradually. When the injection pressure increases 10 MPa, the spray angle peak increases by 1.5° on the average. When the injection pressure reaches 30 MPa or above, the post injection phenomenon disappears basically. Along with the development of the spray, the spray penetration and the spray area increases linearly to a certain extent; the spray angle increases first and then decreases, and finally stabilizes at about 82°.
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