2种结构喷油嘴的流体动力学(CFD)计算及试验研究

CFD Calculation and Experiment Study in Two Kinds of Nozzle

为了满足越来越严格的排放法规和经济性要求，改善柴油机混合气均匀性是有效的措施之一。特别是对于每缸2 气门喷油器偏置结构的发动机，燃烧系统开发的一项重要内容是提高喷油嘴各孔流量的均匀性。应用 FIRE 软件，对无 压力室及小压力室2种不同结构的6孔喷油器进行了三维流体动力学(CFD)计算，小压力室结构在流量系数和各喷孔 流量的均匀性方面都明显优于无压力室结构。对2种结构的喷油嘴进行了试验对比，小压力室喷油器由于提高了混合 气的质量，经济性优于无压力室喷油器。在 HC 排放量上，无压力室喷油器有很明显的优势。

In order to meet strict emission regulations and economic demand, it is one of effective means to improve uniformity of mixture of air and fuel in diesel engine. In the diesel engine in which two charge exchange valves are used and the injector is leaned, one of important things in combustion system study is to improve flow uniformity among holes in the injector nozzle. Three dimensional CFD simulations are made in two kinds of 6 - hole nozzle by means of FIRE software. It is found that the Mini - sac is prior to the VCO nozzle in the flux coefficient and the flow uniformity of holes. After some comparable experiments for two kinds of nozzle are carried out, it is also found that the Mini -sac nozzle has advantage in fuel consumption. On the other hand, the VCO nozzle has obvious advantage in the HC emission.