Quan Yunyun, Zhang Li-Zhi
Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
Langmuir. 2014 Oct 7;30(39):11640-9. doi: 10.1021/la502836p. Epub 2014 Sep 24.
The dynamics of droplets impinging on different microtextured superhydrophobic surfaces are modeled with CFD combined with VOF (Volume of Fluid) technique. The method is validated by experimental data and an analytical model (AM) that is used to predict the penetrating depth and the maximum spreading diameter of an impinging droplet. The effects of geometrical shapes and operating conditions on the spreading and bouncing behaviors of impinging droplets are investigated. Six surfaces with different shapes of pillars are considered, namely, triangular prism, square pillar, pentagonal prism, cylindrical pillar, and crisscross pillar surfaces. The bouncing ability of an impinging droplet on textured surfaces can be illustrated from three aspects, namely, the contact time, the ranges of velocities for rebound and the penetrating depth of liquid in the maximum spreading stage. The surface with crisscross pillars exhibits the best ability to rebound, which can be attributed to its large capillary pressure (PC) and its special structures that can capture air in the gaps during the impinging process.
采用计算流体力学（CFD）结合流体体积（VOF）技术，对撞击不同微纹理超疏水表面的液滴动力学进行了建模。该方法通过实验数据和一个用于预测撞击液滴穿透深度和最大铺展直径的解析模型（AM）进行了验证。研究了几何形状和操作条件对撞击液滴铺展和弹跳行为的影响。考虑了六种具有不同形状支柱的表面，即三棱柱、方柱、五棱柱、圆柱和十字交叉柱表面。撞击液滴在纹理表面上的弹跳能力可以从三个方面来说明，即接触时间、反弹速度范围和最大铺展阶段液体的穿透深度。十字交叉柱表面表现出最佳的反弹能力，这可归因于其较大的毛细压力（PC）及其特殊结构，该结构在撞击过程中能够在间隙中捕获空气。
