发动机缸内环境下二甲醚喷雾特性的试验  

Dimethyl ether spray characteristics under engine-like conditions

作　　者：孙敬[1,2] 张光德[1] 三村昂 金野满 若林大辉 

机构地区：[1]武汉科技大学汽车与交通工程学院,湖北武汉430081 [2]茨城大学理工学研究科,日本茨城日立3160036

出　　处：《江苏大学学报（自然科学版）》2014年第4期386-390,共5页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50975212);湖北省重点实验室开放基金资助项目(ZDK201212)

摘　　要：采用只能拍摄液态喷雾形态的背景散射法,在定容容器内模拟增压发动机实际压力和温度条件,利用超高速摄像机,观察二甲醚喷雾形态.研究了缸内环境、喷射压力、喷孔直径等因素对二甲醚喷雾特性的影响.结果表明:受喷射速度影响,喷雾贯穿距离随着喷射压力的增加而增大;喷雾液态贯穿距离随喷孔直径的增加而增加;在增压发动机高温、高压条件下,由于缸内气体密度和温度增加,喷雾贯穿距离减小;只在常温条件下,二甲醚喷雾周围才出现液滴;与柴油喷雾相比,二甲醚喷雾蒸发更迅速;2种喷雾的外缘处均呈现卷吸状,柴油喷雾分裂是液滴不断破碎微粒化,二甲醚喷雾分裂则是从喷雾液核开始直接迅速蒸发.The background scattering method was used to only take liquid state spray videos. The actual pressure and the temperature conditions in turbocharged engines were simulated in a constant volume vessel, and the DME spray characteristics were investigated with ultra-high speed camera. The influences of environment temperature and pressure, injection pressure and nozzle diameter on spray characteristics of DME were also investigated. The results show that the spray penetration distance increases with the increasing of injection pressure and nozzle diameter. Under the conditions with high temperature and high pressure in turbocharged engine environment, the spray penetration distance decreases when the ambient gas density and the temperature are increased. The liquid drops appear around DME sprays only at normal temperature. Compared with diesel spray, DME spray evaporates more quickly. For both of the two kinds of spray, the outline parts show unregulated wave shape. The diesel spray is broken into particles constantly with droplet splitting, while the DME spray division is directly started from the main spray rapid evaporation.

关 键 词：二甲醚 高温高压 喷雾特性 喷雾贯穿距离 喷雾蒸发 

分 类 号：TK434.6[动力工程及工程热物理—动力机械及工程]