利用LSD技术对高压共轨柴油机喷雾特性SMD的研究

为更好地研究高压共轨柴油机喷雾特性，搭建了柴油喷雾特性激光测试试验系统，基于激光测试手段，利用平面激光粒径测试技术，对高压共轨柴油机喷雾微观特性—索特平均直径进行定量测量，分别考察不同喷孔直径、不同喷油压力下喷雾索特平均直径随时间的变化.研究表明，随着喷孔直径的增加，在1 600 μs内喷雾场中的平均索特平均直径增大；随着喷油压力的增加，在1 400 μs内喷雾场中的平均索特平均直径相对较小，分布也较均匀；喷雾场中粒径的分布趋于粒径较小的方向集中，因此喷雾场中索特平均直径的形态分布近似服从于概率分布中的非中心F分布，并根据其分布形态拟合出相应的非中心F分布函数. 

Spray Characteristics SMD of High-Pressure Common Rail Diesel Engine Based on LSD Technique

To investigate the spray characteristics of high pressure common-rail diesel engines, a test system was constructed. Based on laser sheet drop size(LSD) technique, the micro characteristics of diesel spray were quantitatively tested with the diesel spray laser test system to investigate the variation law of Sauter mean diameter(SMD) over time in different nozzle diameters and injection pressure. Experimental results show that with the increase of the nozzle diameter, the average SMD of the spray field increases in 1 600 μs. With the increase of the injection pressure, the average SMD of the spray field can be smaller in 1 400 μs and the distribution distributes uniformly.The droplet size distribution tends to be concentrated in the smaller diameter direction, therefore the distribution of droplet size in the spray field is similarly subjected to the noncentral F-distribution, and the noncentral F-distribution function is fitted according to the distribution pattern.