Twin-orifice 喷嘴的闪急沸腾喷雾特性.PDF

第 22 卷 第 2 期 燃 烧 科 学 与 技 术 Vol.22 No.2 2016 年 4 月 Journal of Combustion Science and Technology Apr. 2016 DOI 10.11715/rskxjs.R201504011 Twin-orifice 喷嘴的闪急沸腾喷雾特性 具德浩，乔信起，肖 进，黄 震 (上海交通大学动力机械与工程教育部重点实验室，上海 200240) 摘 要 ：利用多阈值图像处理法对 Twin-orifice 喷嘴的闪急沸腾喷雾特性进行研究．通过高速照相机分析在喷射开 始、发展及结束时喷嘴的内部流场和雾化形态，研究膨胀室内部形核、气泡生长等如何影响雾化特性．较大的膨胀 室为液化 R134a 的气化和沸腾提供了更多的空间和时间，其射流被高气/液质量比的两相流稀释．进口孔径小的喷嘴 喷射流量小，膨胀室中蒸发潜热消耗快并导致腔内温度迅速下降，使其过热度较低，最终导致喷雾锥角小，液滴空 间分布浓度低． 关键词 ：闪急沸腾喷雾；Twin-orifice 喷嘴；低压喷雾；多阈值法 中图分类号：O359 文献标志码 ：A 文章编号 ：1006-8740 (2016)02-0102-06 Flash-Boiling Atomization Characteristics of a Twin-Orifice Injector Ju Dehao ，Qiao Xinqi ，Xiao Jin ，Huang Zhen (Key Laboratory of Power Machinery and Engineering ，Ministry of Education ， Shanghai Jiao Tong University ，Shanghai 200240 ，China) Abstract ：This work is to investigate the internal flow pattern and macroscopic spray characteristics of R134a (a rep- resentative of dimethyl ether)actuated through a Twin-orifice injector．The internal flow and spray images were re- corded at various times after the start of actuation using a visualization system consisting of a high speed digital cam- era and a metal halide lamp as the illumination source．Internal nucleation ，bubble growth in the expansion chamber and external liquid atomization were observed simultaneously during the actuation．The transient continuous spray cone angles were measured in each