中文摘要：

为了解高压共轨喷嘴结构对喷雾的影响,试验采用三维相位多普勒粒子分析仪（PDPA）,在高喷射压力条件下研究了不同的喷嘴结构的喷雾粒径空间分布情况.结果表明：高压燃油喷雾的粒径分布呈现轴线大、两边小的趋势,并在喷雾边缘稍微增加;同时随着喷射压力的增加,喷雾索特平均直径（SMD）的分布呈现粒径减小的趋势,小粒径区域逐渐向喷嘴顶端靠近,喷雾雾化效果随喷射压力增加而改善.随着喷孔直径的减小,喷雾总体SMD呈减小趋势;当喷孔直径减小到一定程度时,进一步减小喷孔直径对喷雾雾化效果的影响逐渐减弱.孔径为0.18,mm的喷嘴,喷雾SMD随着长径比（L/D为3.89~5.00）的增加而增大;孔径为0.13,mm的喷嘴,喷雾SMD随着长径比（L/D为5.38~7.69）的增加而降低.

英文摘要：

To explore the effect of nozzle geometry on spray of a high pressure common rail injector,the droplet size distribution of different nozzle geometries was measured under high injection pressure condition using the phase Doppler particle analyzer（PDPA）.Droplet size distribution shows that the Sauter mean diameter（SMD）in the central axis is larger than that of the outer side,and the SMD in the periphery increases slightly.With the increase of injection pressure,SMD decreases remarkablely,and small particles are close to the injection tip.The spray atomization is improved with the increase of injection pressure.With the decrease of orifice diameter,the overall SMD is decreased.the effect of orifice diameter on spray atomization becomes weak.When orifice diameter decreases to a certain value,further decrease in orifice diameter has a little influence on spray atomization.For the 0.18,mm nozzle,the overall SMD increases with the increase of length-diameter ratio（from 3.89 to 5.00）,while it decreases with the increase of length-diameter ratio（from 5.38 to 7.69）for the 0.13,mm nozzle.