中文摘要：

利用STAR-CD软件模拟研究了3种燃烧室形状对柴油-天然气双燃料发动机性能的影响,3种燃烧室分别为ω形燃烧室、八边哑铃形燃烧室和圆柱形燃烧室。研究发现,八边哑铃形燃烧室因为减小了喉口直径,增加了挤流强度,使得气缸内的湍动能增强,火焰传播速度加快,燃料利用率提高,同时,在燃烧室的底部设计凸台,能引导燃烧室内的气流运动,并引导柴油向燃烧室的底部扩散,促进着火点的广泛分布。因此,八边哑铃形燃烧室的缸内平均压力、平均温度和指示热效率最高,天然气剩余比例最小。

英文摘要：

The influences of three kinds of combustion chamber shape on the performance of diesel and natural gas dual-fuel engine were studied with STAR-CD software.The three kinds of combustion chamber wereω-shaped combustion chamber,octagonal dumbbell-shaped combustion chamber and cylinder-shaped combustion chamber.The results show that the octagonal dumbbell-shaped combustion chamber has better performance.The in-cylinder turbulent kinetic energy strengthens,the flame propagation accelerates and the fuel utilization ratio increases due to the squish flow caused by reducing dumbbell throat diameter.Meanwhile,the designed boss at the bottom of the combustion chamber can guide the mixture movement,and promote diesel diffusion to the chamber bottom,resulting a wide distribution of ignition point.Therefore,the in-cylinder average pressure,average temperature and indicated thermal efficiency of octagonal dumbbell-shaped combustion chamber is the highest and the proportion of remained natural gas is the least.