中文摘要：

燃料水花是直接注射引擎燃烧的枢轴的过程。水花模拟的 Theaccuracy 决定燃烧计算的可靠性。然而，在大地穴和商业 CFD 代码的水花模拟的传统的技术是很易受影响的衣服根除分辨率。作为后果，预言引擎性能和排放能取决于计算网孔。这个问题的二个主要原因是微滴碰撞算法并且在气体和液相之间联合。以便改进水花模拟的精确性，原来的大地穴代码用生气网孔微滴碰撞(CMC ) 被修改算法和煤气的阶段速度插值算法。在经常的卷仪器和 D.I 柴油机引擎，在水花模拟精确性的修改大地穴代码的改进分别地从水花结构，预言的平均落下尺寸和水花尖端穿入被检查。结果在格子相关性显示出戏剧的减少。与这些变化，水花结构的弄歪的现象被消失。在预言的平均落下尺寸的不确定性从 30 ～ 5 瓮被减少反复无常的体积仪器计算，和不确定性进一步在引擎模拟被归结为 2 亩 m。在引擎模拟的预言的水花尖端穿入也在中等、好的网孔有更好的一致性。

英文摘要：

Fuel spray is the pivotal process of direct injection engine combustion. The accuracy of spray simulation determines the reliability of combustion calculation. However, the traditional techniques of spray simulation in KIVA and commercial CFD codes are very susceptible to grid resolution. As a conse- quence, predicted engine performance and emission can depend on the computational mesh. The two main causes of this problem are the droplet collision algorithm and coupling between gas and liquid phases. In order to improve the accuracy of spray simulation, the original KIVA code is modified using the cross mesh droplet collision （CMC） algorithm and gas phase velocity interpolation algorithm. In the constant volume apparatus and D.I. diesel engine, the improvements of the modified KIVA code in spray simulation accuracy are checked from spray structure, predicted average drop size and spray tip penetration, respectively. The results show a dramatic decrease in grid dependency. With these changes, the distorted phenomenon of spray structure is vanished. The uncertainty in predicted average drop size is reduced from 30 to 5 pm in constant volume apparatus calculation, and the uncertainty is further reduced to 2 pm in an engine simulation. The predicted spray tip penetrations in engine simulation also have better consistency in medium and fine meshes.