已报道过采用多次喷油的预混合压缩着火技术降低排放、噪声和燃油耗的柴油机燃烧系统。这一燃烧系统的关键是第2次喷油的喷油定时和喷油量。运用光学发动机的缸内可视化和数值模拟技术发现,浓混合气区域的火焰氧化加速,通过设定最佳的第2次喷油定时,以及适当的喷射间隔,可以抑制喷嘴附近区域碳粒的形成。燃烧噪声频谱分析发现,在2个压力升高率峰值之间,燃烧噪声得以降低。 Diesel engine combustion systems have been reported that use premixed compression ignition with multiple injections to reduce emissions, noise, and fuel consumption. The key to this combustion system is the second fuel injection timing and fuel injection quantity. Using in-cylinder visualization and numerical simulation of an optical engine, it was found that the flame oxidation in the rich-mixed gas region is accelerated and the formation of carbon particles in the vicinity of the nozzle can be suppressed by setting the optimum second injection timing and the proper injection interval . Spectrum analysis of combustion noise found that the combustion noise was reduced between the two peaks of the rate of pressure rise.