Recent results have concluded that the efficacy of compression stroke injections in enhancing natural thermal stratification are dependent on the injector’s included angle. Therefore, there is a need to further understand how different hardware affects the efficacy of thermally stratified compression ignition. In this study, three injector included angles are considered: 150°, 118°, and 60°. Compression stroke injection timing sweeps are performed with these three injectors using two distinct piston geometries: a re-entrant bowl piston geometry found in a production, light-duty diesel engine, and a custom-made open, shallow bowl piston geometry, designed to reduce surface-to-volume ratio. Using an equivalence ratio of 0.5 and a split fraction of 80%, it was found that, with the re-entrant bowl piston geometry, the 150° injector displayed high controllability over the burn duration and was able to elongate the burn duration by a factor of 1.8×. The 118° injector displayed slight controllability over the burn duration, while the 60° injector displayed no controllability. With the open bowl piston geometry, the 150° maintained high controllability over the burn duration, albeit with less efficacy. The 60° injector still had no controllability and now the 118° injector had no controllability. The low surface-to-volume ratio of the shallow bowl piston led to less natural thermal stratification than the re-entrant bowl piston geometry, which impacted the compression stroke injection’s ability to control the burn rate. Therefore, the hardware setup that achieves the highest efficacy is a re-entrant bowl-like piston geometry with a wide spray angle injector.

最近的结果得出结论，压缩冲程喷射在增强自然热分层方面的功效取决于喷射器的夹角。因此，需要进一步了解不同的硬件如何影响热分层压缩点火的功效。在本研究中，考虑了三个喷射器夹角：150°，118°和60°。使用这三个喷射器使用两个不同的活塞几何形状进行压缩冲程喷射正时扫描：在生产型轻型柴油发动机中发现的凹角活塞几何形状，以及旨在减少尺寸的定制开放，浅碗活塞几何形状体积比。使用0.5的当量比和80％的分流比，发现在凹腔活塞几何形状的情况下，150°喷射器在燃烧期间显示出高度可控性，并且能够将燃烧持续时间延长1.8倍。118°喷油器在燃烧期间显示出轻微的可控性，而60°喷油器则显示无可控性。采用开碗式活塞的几何形状，尽管效率较低，但150°在燃烧期间仍可保持较高的可控性。60°喷油器仍然没有可控性，现在118°喷油器没有可控性。浅碗活塞的低表面积体积比导致比凹腔活塞几何形状更少的自然热分层，这影响了压缩冲程喷射控制燃烧速率的能力。因此，获得最高功效的硬件设置是具有宽喷射角喷射器的凹入碗状活塞几何形状。