The role of a split injection in the mixture formation and combustion characteristics of a diesel spray in an engine-like condition is investigated. We use large-eddy simulations with finite rate chemistry in order to identify the main controlling mechanism that can potentially improve the mixture quality and reduces the combustion emissions. It is shown that the primary effect of the split injection is the reduction of the mass of the fuel-rich region where soot precursors can form.

Furthermore, we investigate the interaction between different injections and explain the effects of the first injection on the mixing and combustion of the second injection. Results show that the penetration of the second injection is faster than that of the first injection. More importantly, it is shown that the ignition delay time of the second injection is much shorter than that of the first injection. This is due to the residual effects of the ignition of the first injection which increases the local temperature and maintains a certain level of combustion some intermediates or radical which in turn boosts the ignition of the second injection.

研究了分流喷射在发动机状条件下在柴油喷雾的混合物形成和燃烧特性中的作用。我们使用具有有限速率化学性质的大涡模拟来确定主要的控制机制，该机制可以潜在地改善混合物质量并减少燃烧排放。结果表明，分流喷射的主要作用是减少了可形成烟灰前体的富燃料区域的质量。

此外，我们研究了不同喷射之间的相互作用，并解释了第一次喷射对第二次喷射的混合和燃烧的影响。结果表明，第二次注射的渗透速度比第一次注射的渗透速度快。更重要的是，表明第二次喷射的点火延迟时间比第一次喷射的点火延迟时间短得多。这是由于第一次喷射的点火的残余作用，该残余作用提高了局部温度并保持一定程度的燃烧，某些中间产物或自由基则反过来又增强了第二次喷射的点火。