不同液膜厚度条件下液滴/液膜碰撞特性  

Effect of Liquid Film Thickness on the Behaviors of Droplets Impacting on Film

作　　者：方龙 张云峰 陈博[1] 随亚光[1] FANG Long;ZHANG Yunfeng;CHEN Bo;SUI Yaguang(Northwest Institute of Nuclear Technology,Xi’an 710024,China)

机构地区：[1]西北核技术研究所,西安710024

出　　处：《现代应用物理》2023年第4期184-189,共6页Modern Applied Physics

基　　金：强脉冲辐射环境模拟与效应全国重点实验室基金资助项目(13062001)。

摘　　要：为获得不同液膜厚度条件下液滴/液膜碰撞特性,开展了大量的液滴/液膜碰撞试验,分析了液膜厚度对液滴/液膜碰撞形态的影响,构建了考虑液膜厚度影响的液滴/液膜碰撞形态辨识准则,确定了液滴/液膜碰撞产生的二次液滴数量与碰撞工况条件间的无量纲关系。研究结果表明:在碰撞初始阶段,液滴/液膜碰撞形态与液膜厚度无关,液滴顶部速度与入射速度一致,而空腔底部扩展速度约为液滴入射速度的0.4倍;随着碰撞时间的继续,液膜厚度对液滴/液膜碰撞形态有较大影响,液膜厚度越小,越不利于二次液滴和中心射流的产生,空腔深度扩展速度呈现出随无量纲液膜厚度减小而下降的趋势;当飞溅参数KCossali大于1 500+1 000×δ-0.8时,液滴/液膜的碰撞形态为溅射,给出了发生飞溅后产生的二次液滴数量的计算公式。In this paper,a large number of droplets impacting on liquid film experiments are carried out to obtain the impacting behaviors of droplets and liquid films with different liquid film thickness.The effect of liquid film thickness on the droplet impacting on liquid film morphology is analyzed,and a droplet impacting on liquid film morphology identification criterion considering the influence of liquid film thickness is constructed to determine whether the impacting outcome is splashing or not.The dimensionless relationship between the number of secondary droplets generated by droplets impacting on liquid film and the operating conditions is established.The results indicate that it is independent of the thickness of the liquid film,and the velocity at the top of the droplet is the same as the impacting velocity during the initial stage,while the crater expanding velocity is about 0.4 times the impacting velocity.The film thickness has a significant influence on the impacting morphology.The smaller the thickness of the liquid film,the harder the generation of secondary droplets and central jets.The crater expanding velocity decreases with the decrease of the film thickness.When the splashing parameter K Cossali is greater than 1500+1000×δ-0.8,the impact outcome of droplets impacting on liquid film will be splashing,and a calculation formula for the number of secondary droplets generated after splashing is given.

关 键 词：液滴 液膜厚度 空腔 辨识准则 二次液滴 中心射流 

分 类 号：TG156[金属学及工艺—热处理] O35[金属学及工艺—金属学]