连续均匀热气流中液核/袋状破碎特性实验

为了获得热气流中单液滴液核/袋状破碎特性，采用高速摄像机对液滴变形、破碎过程进行了捕获.实验设计工况下所得结果表明:①液核/袋状破碎过程是液滴中液体流动与外界气动力共同作用下发生的，可以分为伞形破碎与勺形破碎；②液滴初始直径减小、气流温度增加，都可以降低液滴发生液核/袋状破碎所需最小气动力；③液滴破碎特征时间，随气动力增加呈负增长变化趋势，其值与变化梯度都随液滴初始直径增加而增大；④子液滴质量分数随气动力增加而增加，且随液滴初始直径增加而减小；⑤子液滴群质量分数的空间离散度都随气动力增加而增加. 

Experimental investigations on breakup characteristic of single droplet in the core/bag breakup regime inthe continuous uniform heating airflow

In order to obtain characteristics of single droplet deformation and breakage in a continuous and uniform air jet flow,the high-speed cameras were applied to measure the single droplet deformation and breakage.In the experimental conditions,experimental results show that:(1) The process of droplet deformation and breakage in the core/bag breakup regime is caused by the combination effects of liquid-flow and external aerodynamics.It can be divided into umbrella-type breakup regime and dipper-type breakup regime.(2) The reduction of original diameters of droplet and the increase of airflow temperature could decrease the minimum requirements of aerodynamic force on the core/bag breakup.(3) The characteristic time of droplet breakup has a negative relationship with the aerodynamics,while its value and change gradient are both positively associated with the original droplet diameter.(4) The percentage of sub-droplet quality raises with the increase of aerodynamics,but decreases with the increase of droplet original diameter.(5) The spatial dispersion of quality percentage of sub-droplet increases with the rise of aerodynamics.