超亲水多孔表面的小液滴发射行为及动力学特性

发布时间：2018-02-09 16:02

  本文关键词： 超亲水 多孔介质 液滴 动力学 渗透 小液滴发射　出处：《化工学报》2016年09期 　论文类型：期刊论文

【摘要】：构建了4类不同的超亲水微/纳多孔结构,通过低速液滴撞击实验研究了多孔介质的结构参数如微/纳尺度特征、孔隙率以及表面粗糙度等对液滴行为和动力学特性的影响。结果表明:多孔表面液滴的早期扩散符合惯性扩散的幂函数规律,并且纳米级结构孔隙率的变化对幂函数关系无显著影响,微米级结构C和α的值随孔隙率增大而降低,粗糙度的提高能够导致C值增大。发现了两种新颖的小液滴发射模式,分别称为第1阶段断裂和第2阶段断裂。纳米级多孔结构发生第1阶段断裂的原因在于较快的惯性扩散速度和较长的惯性时间;第2阶段断裂发生于微米级多孔结构,原因在于渗透的强化导致液滴高度的快速下降以及惯性时间的缩短。
[Abstract]:Four kinds of superhydrophilic micro / nano porous structures were constructed. The structural parameters such as micro / nano scale characteristics of porous media were studied by low speed droplet impact experiments. The effects of porosity and surface roughness on droplet behavior and kinetic characteristics are investigated. The results show that the early diffusion of droplets on porous surfaces conforms to the law of power function of inertial diffusion. The change of porosity of nanostructure has no significant effect on the power function relationship. The values of C and 伪 of micron structure decrease with the increase of porosity, and the increase of roughness can lead to the increase of C value. Two novel emission modes of small droplets have been found. They are referred to as the first stage fracture and the second stage fracture respectively. The first stage fracture of nanometer porous structure is caused by the faster inertial diffusion velocity and longer inertial time, and the second stage fracture occurs in the micrometer porous structure. The reason is the rapid drop of droplet height and the shortening of inertial time due to the enhancement of permeation.
【作者单位】： 华北电力大学新能源电力系统国家重点实验室多相流动与传热北京市重点实验室;
【基金】：国家自然科学基金项目(51436004,51276061) 中央高校基本科研业务费专项资金项目(JB2015202)~~
【分类号】：O35
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