柴油机喷雾夹角对缸内三维流场的影响

运用CFD软件对直喷柴油机燃烧室中的喷雾及燃烧过程进行数值计算,考察了不同喷雾夹角下缸内三维流场及NOx排放的差异,并将计算结果进行了对比分析。结果表明喷雾夹角的增加使凹坑内的空气利用率变差,并使得燃烧高温区域更加接近气缸壁面以及缸盖平面;喷雾夹角的减小使燃烧过程中生成的NOx排放增加并增加了喷油器的热负荷。

Effect of Inject Spray Angle on the Cylinder - in 3D Flow Distribution of Diesel Engine

The paper gives calculation on the inject spray and combustion process in the combustion chamber of the direct injection diesel engine using the CFD software , analyze the differences of cylinder - in 3D flow distribution and NOx emission and the calculation results in different inject angle. The results shows that air in the combustion chamber concave gets to be consumed much worse when the inject angle increases and the high temperature zone is much close to the cylinder wall and cylinder head surface. Reduction of inject spray angle causes increase of NOx emission and injector thermal load.