Experiments and simulations were conducted to study effects of charge density, temperature, and oxygen concentration on the mixing-controlled engine combustion pathway in heavy-duty diesel engines. Due to the inherent heterogeneity of diesel combustion in high-load operations, the rich and lean mixtures are simultaneous present. The mass and accompanying heat transfers were found to be decisive in determining the combustion path. The chemical transformation from a richer mixture to a leaner mixture is primarily driven by charge density, which activates the combustion process, and reduction in oxygen concentration, which stagnates the mass and heat transfer and chemical transformation, reduces the reactivity of the mixtures. The difference in mass and heat transfer processes causes differences in the mass fractions of mixtures with different equivalence ratio intervals. The different mixtures produce different mass fractions of intermediate combustion products (carbon dioxide, CO), different heat releases, and different mass temperature distributions. It is found that the accumulated CO correlates well with the gross indicated thermal efficiency and soot emission; the mass averaged temperature and the high temperature abidance scale (HTAS) correlate well with NO_x emissions. A significant optimization of the overall engine performance could be achieved by simultaneously minimizing the HTAS and accumulated CO.

进行实验和模拟以研究装料密度，温度和氧气浓度对重型柴油发动机的混合控制发动机燃烧路径的影响。由于高负荷运行中柴油燃烧的固有异质性，因此同时存在浓混合气和稀混合气。发现质量和伴随的热传递对确定燃烧路径起决定性作用。从较浓的混合物到较稀的混合物的化学转化主要由电荷密度驱动，电荷密度激活了燃烧过程，氧气浓度的降低使质量停滞，传热和化学转化降低了混合物的反应性。质量和传热过程的差异导致具有不同当量比间隔的混合物的质量分数差异。不同的混合物产生不同质量分数的中间燃烧产物（二氧化碳，一氧化碳），不同的热量释放和不同的质量温度分布。发现累积的CO与总的指示热效率和烟尘排放良好相关。质量平均温度和高温持续量表（HTAS）与NO密切相关 发现累积的CO与总的指示热效率和烟尘排放良好相关。质量平均温度和高温持续量表（HTAS）与NO密切相关 发现累积的CO与总的指示热效率和烟尘排放良好相关。质量平均温度和高温持续量表（HTAS）与NO密切相关_x排放量。通过同时最小化HTAS和累积的CO，可以实现整体发动机性能的重大优化。