初始直径对单液滴破碎特性影响的试验

为了获得均匀横向气流中单液滴变形、破碎特性,采用高速摄像机对液滴的变形、破碎过程进行了测量.通过试验获得了液滴初始直径对液滴破碎模式、变形时间、变形与破碎总时间、无量纲索太尔平均直径的影响.在试验设计工况下所得结果表明:液滴破碎临界韦伯数随液滴初始直径的增加而增加;液滴初始直径增加使得液滴由单一的破碎模式转变成多种破碎模式共生的混合型破碎模式;相同韦伯数下,在初始直径尺寸较大的区域液滴变形时间、变形与破碎总时间都比尺寸较小的区域要大,变形时间随韦伯数增加呈先减小后不变的线性变化关系,而变形与破碎总时间随韦伯数增加呈先减小后增加再减小的线性变化关系;液滴初始直径对无量纲索太尔平均直径的影响能力要强于气液初始相对速度对其影响.

Experiment on impact of initial diameter on breakup characteristic of single droplet

The high-speed camera was applied to measure droplet deformation and breakup in the continuous and uniform air jet flow. Impacts of the initial diameter on breakup mode, deformation time, deformation and breakup total time and non-dimensional Sauter mean diameter were obtained. Result shows that,critical Weber number increases with the increasing initial diameter. The breakup model is changed into hybrid breakup model constituted by many single breakup models with the increasing initial diameter. Under the same Weber numbers, the deformation time and deformation and breakup total time in the region of larger diameter are both larger than the region of the smaller diameteras the Weber number increased, the deformation time showes the linear variation of first decreasing and then keeping the same, and the deformation and breakup total time showes the linear variation of first decreasing then increasing and decreasing again. The impact of the initial diameter is stronger than the impact of initial relative velocity of gas-liquid on non-dimensional Sauter mean diameter.