Twin-orifice喷嘴的闪急沸腾喷雾特性  

Flash-Boiling Atomization Characteristics of a Twin-Orifice Injector

作　　者：具德浩 乔信起[1] 肖进[1] 黄震[1] 

机构地区：[1]上海交通大学动力机械与工程教育部重点实验室,上海200240

出　　处：《燃烧科学与技术》2016年第2期102-107,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51306118);中国博士后科学基金资助项目(2013M531172)

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.This work is to investigate the internal flow pattern and macroscopic spray characteristics of R134a（a representativeof dimethyl ether）actuated through a Twin-orifice injector.The internal flow and spray images were recordedat various times after the start of actuation using a visualization system consisting of a high speed digital cameraand a metal halide lamp as the illumination source.Internal nucleation,bubble growth in the expansion chamberand external liquid atomization were observed simultaneously during the actuation.The transient continuous spraycone angles were measured in each case.The relationship between the internal boiling flow in the expansion chamberand external flash-boiling atomization was analyzed.Larger expansion chamber provided more residence time forboiling,and sprays were diluted by the mixture flow with higher gas/liquid mass fraction.

关 键 词：闪急沸腾喷雾 Twin-orifice喷嘴 低压喷雾 多阈值法 

分 类 号：O359[理学—流体力学]