油束撞击形成混合气及其燃烧过程的机理研究

本文介绍了用多次喷雾叠加摄影与激光粒子分析技术对燃油喷雾撞击前后的粒径、贯穿度以及喷雾锥角等因素变化所进行的观察和测量以及介绍了利用双像高速摄影技术对燃油束撞击雾化形成的混合气以及燃烧过程特点的研究。结果表明，燃油经撞击后可显著地增大油束扩散角、不同程度地影响了燃油束的贯穿度，但对燃油束撞击前后滴径变化的影响不大。混合气形成及其燃烧过程的高速摄影研究结果表明，燃油束撞击雾化对加快燃油与空气的混合并促进其火焰扩展起到重要作用。另外撞击反弹方向和喷油压力等也是影响混合气形成和燃烧的重要因素。

INVESTIGATION INTO CHARACTERISTICS OF FUEL SPRAY IMPINGEMENT AND ITS MIXING AND BURNING PROCESS

This paper reports the droplet size and distribution, penetration and diffusion angle of fuel spray before and after impingement by multiple-picture overlapping photography and laser technology, as well as the fuel spray mixing and burning process in a direct injection diesel engine by high speed photography. The obtained results showed that, after impingement the diffusion angle of fuel droplet changed much bigger than that of before impingement, and the same to the penetration, but the droplet size and distribution remained unchanged. The experimental results also illustrated that it is importance of the fuel impingement to promote fuel and air mixing and speed up burning process. The direction of fuel spray after impingement and opening pressure of nozzle were important factors to influence fuel and air mixing and burning process.