直喷汽油机喷雾碰壁特性实验研究

Experimental research on spray and impingement characteristics of direct injection gasoline engine

本文采用折射率匹配方法,在非蒸发环境下研究喷雾碰壁后形成油膜的质量、面积和厚度变化特点,获得油膜在不同容弹压力和喷射压力下变化规律并分析其原因。通过Mie散射方法,研究与上述相同工况下喷雾碰壁后油束变化规律,并与RIM实验结果进行对比。实验结果表明,容弹压力对喷雾碰壁后油膜的形成有重要作用,容弹压力较低时,油膜质量、面积和最大厚度随喷射压力的升高而减小;容弹压力较高时,油膜质量、面积和最大厚度随喷射压力的升高而增大。

The mass, area and thickness of the fuel film with different ambient pressures and injection pressures under non-evaporation condition are studied by utilizing the refractive index matching method.The spray impingement images are obtained by utilizing Mie scattering method in the same conditions as described above.Both results are compared mutually and analyzed.The results show that the ambient pressure play a key role in spray and impingement.When the ambient pressure is at a low value, the fuel film quality, area and maximum thickness decrease with an increase of injection pressure, but when the ambient pressure is at a high value, fuel film quality, area and maximum thickness increase with an increase of injection pressure.