nozzle hole

In order to gain ideal spatial distribution of fuel vapor, the swirl ratio should be decreased with increasing number of nozzle hole.

为了获得理想的燃油蒸气空间分布，涡流比的匹配值应随着喷孔数的增加而逐渐减小；

The reasonable combination of nozzle hole number, impingement angle and valve opening pressure is very important to the new conical spray.

喷孔数、碰撞角度和启喷压力三者的合理配合对第三代伞状喷雾至关重要。

The combustion process in the combustion chamber was simulated by use of KIVA-ⅱ code for direct-injection diesel engine. The fuel vapor quantity and combustion temperature and NOx concentration were calculated through changing the size of the nozzle hole.

利用KIVA-Ⅱ程序模拟计算直喷式柴油机燃用柴油时缸内的燃烧过程，如混合气形成过程、缸内温度场、主要有害物质NOx的生成浓度分布等。

The results show that injection timing, total nozzle hole area, inlet water temperature and inlet air temperature have obvious effect on exhaust value of CO, HC and NOx.

试验结果表明，喷油提前角、喷孔总面积、进水温度及进气密度对CO，HC，NO x的排放量有明显的影响。