丝米级矩形沟槽表面的水滴融合过程  

Coalescence Process of Droplets on Decimillimeter-Scaled Grooved Surfaces

作　　者：胡海豹[1] 何强[1] 黄苏和[1] 薛群基[2] 杜向党[1] 

机构地区：[1]西北工业大学航海学院,西安710072 [2]宁波海洋新材料重点实验室中国科学院宁波工业技术研究院,浙江宁波315201

出　　处：《上海交通大学学报》2016年第2期209-214,221,共7页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金重点项目(51335010);中央高校基本科研业务费专项资金项目(3102015ZY017);西北工业大学研究生创意创新种子基金项目(Z2015002);长安大学公路养护装备国家工程实验室开放基金项目(2013G1502048)资助

摘　　要：采用高速摄像技术测试丝米级矩形沟槽表面的水滴融合过程,分析了平行沟槽、垂直沟槽方向的2个等大、非等大水滴间的融合和振荡规律.试验中,采用壁面预埋针头法实现了预置静态水滴与缓慢生长的准静态水滴的融合.结果表明,水滴的融合过程包含融合、振荡2个阶段.在等大水滴间的融合过程中,当水滴平行于沟槽方向融合时,受到沟槽的引导作用,沿沟槽方向的水滴振荡剧烈并伴随接触线的往复移动;当水滴垂直于沟槽方向融合时,受到垂向肋间"能垒"的限制,垂直沟槽方向的水滴振荡较弱,且接触线位置无明显变化,但竖直方向的水滴振幅显著.在非等大水滴间融合时,小水滴被吸引到大水滴一侧,融合过程呈现出不对称性,且液桥高度峰值、融合时间及接触线长度均随两水滴总体积的增加而增大.This paper investigated the coalescence of two droplets on decimillimeter-scaled grooved surfaces by using a high-speed camera and compared the coalescence process of isometric/anisometric droplets on parallel/vertical grooved surfaces.During the experiment,a syringe needle was inserted from the bottom of the substrates in order to obtain a horizontal coalescence of a preplaced static droplet and a slowly growing quasi-static droplet.The results show that the whole coalescence process can be divided into the coalesce process and the oscillation process.When the droplets are isometric,on parallel grooved surfaces,due to the guiding effect of grooves,they oscillate sharply by the direction of grooves,accompanied by reciprocating contact line.On vertical grooved surfaces,limited by the energy barrier of vertical grooves,the oscillation of droplet is weaker and the contact line is almost fixed,while the vertical amplitude of oscillation is distinct.Different phenomena are observed when the droplets are anisometric：the smaller droplet isattracted to the other side,resulting in an asymmetrical coalescence process.Besides,the height of liquid bridge,the lasting time of coalescence and the length of contact line increase as the overall volume of the two droplets increases.

关 键 词：矩形微沟槽 水滴 融合 桥状物 

分 类 号：O647.5[理学—物理化学]