燃烧室形状对柴油机性能影响的研究

为研究混合气的形成状况和燃烧质量，探索燃烧室形状对柴油机性能的影响，本文应用STAR—CD程序对不同几何形状的燃烧室内的燃油雾化、燃烧进行三雏数值模拟。计算结果表明，燃烧室的形状对燃烧过程有着重要影响。缩口燃烧室具有较大的挤流强度，较长的涡流持续期，较合理的涡流分布，更有利于混合气的形成，可以进一步加速扩散燃烧，产生较高的缸内压力和温度，具有最好的燃烧性能。直口燃烧室燃烧性能相对较差，敞口燃烧室的最差。但是缩口燃烧室的热应力较大，残余废气不易排除，实现增压比较困难。

Studying on the Performance Effected by the Shape of Combustion Chamber

In order to investigate the mixture formation and combustion quality,find the rule of performance effected by the shape of combustion chamber,atomization and combustion of fuel in different geometrical combustion chambers were simulated using STAR-CD.The results show that the shape of chamber plays an important role to combustion process.The contracted cave(chamber A) has much strong squish,which can last for long-term period and distributs reasonably.That is beneficial to the formation of the mixture.The diffuse combustion could be enhanced with higher pressure and temperature,which demonstrates chamber A has the best combustion performance.But the thermal stress of chamber A is higher,and residual gas is not easy to be dischargd.It is difficult to realize superchargbe.