可控热氛围中喷雾的雾化特性和粒径分布  

Atomization and Droplet Size Distribution of Diesel Sprays Issuing into a Hot Vitiated Co-Flow

作　　者：张青[1] 秦秋实[1] 邓俊[1] 吴志军[1] ZHANG Qing, QIN Qiushi, DWG Jun , WU Zhijun(School of Automotive Studies, Tongji University, Shanghai 201804, Chin)

机构地区：[1]同济大学汽车学院,上海201804

出　　处：《同济大学学报（自然科学版）》2018年第6期842-847,共6页Journal of Tongji University:Natural Science

基　　金：国家自然科学基金(91441125;51576141)

摘　　要：基于可控热氛围燃烧器提供的均匀温度场,使用高速摄像机和激光衍射粒度仪对300~673K协流温度范围内的柴油喷雾进行测量.结果表明,随协流温度升高,相同时间内的喷雾贯穿距减小,喷雾锥角先增大后减小.在300K协流下,索特平均直径处于10~20μm之间,随轴向高度升高而略有增加,大尺寸液滴的直径在离开喷孔20~40mm过程中下降了17%.各粒径参数随径向距离的增大而减小.粒径一致性随着轴向和径向距离的增加而提高.在协流温度从300K上升至673K的过程中,索特平均直径从15μm上升到24μm,粒径一致性提高,蒸发使得小尺寸液滴大量消失.The information of diesel spray in a stable hot coflow（300—673 K）is recorded with a high-speed camera and a laser diffraction instrument.The results show that as the coflow temperature increases,the spray penetration decreases and apeak spray angle appears.When the co-flow temperature is equal to 300 K,the Sauter mean diameter of the droplets is between 10 μm and 20 μm and slightly increases along the axis.Dv90 decreases by 17% from 20 mm to 40 mm in the axial distance.The size distribution parameters decrease along the radius.The uniformity of the droplet sizes becomes better as the axial/radial distance increases.The Sauter mean diameter increases from15μm to 24μm and the uniformity increases as the co-flow temperature increases from300 K to 673 K,owing to the fast evaporation of small droplets.

关 键 词：发动机 喷雾 热氛围 激光衍射 粒径分布 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]