应用LDV测量柴油机高压喷雾对空气的卷吸

用猝发信号频谱分析多普勒测速仪（ＢＳＡ－ＬＤＶ）对柴油机高压喷雾的空气卷吸速度进行了测量，并分析了喷雾卷吸空气的量，结果发现，随喷油压力提高，空气卷吸速度增大；随轴向距离的增加，喷雾对空气的卷吸速度由小变大，再逐渐变小；接近喷 雾头部，喷雾对周围空气的作用将由卷吸成为排推，与气体射流比较，柴油机高压喷雾卷吸空气的量约小２／３。

LDV STUDY ON ENTRAINMENT AIR FLOW OF HIGH PRESSURE SPRAYS

n this paper, the velocity of entrainment air flow in the high pressure diesel fuel spray was measured by using a LDV system with a bust spectrum analyzer. The value of air entrainment rate was also estimated. The results show that the velocity of entrainment air increases with the rise of the fuel injection pressure. When the distance from the nozzle increases, the velocity of entrainment air will increase first and then decrease gradually. The environment air is pushed by the spray head. The air entrainment rate of the high pressure spray is only one third of that of a gas jet on the same condition.