液滴撞击超疏水碳纳米管阵列表面的行为研究

The Characteristics Study of Droplet Impingement on Superhydrophobic Carbon Nanotube Arrays

实验研究了不同韦伯数(We)时液滴碰撞碳纳米管阵列表面的动态过程行为,并借助改进的水平集方法对液滴碰撞过程进行了数值模拟。模拟过程中,分别引入了接触角动态变化的Kistler模型和Blake模型,并就液滴铺展因子和顶点高度等方面将模拟与实验结果进行了对比分析。结果表明:在We=1.4～110范围内液滴碰撞都经历了相似的铺展-收缩-弹跳过程,不同We时模拟和实验结果都比较接近;在液滴铺展阶段,依据Kistler模型的模拟结果与实验值更接近,而在收缩阶段,依据Blake模型的模拟结果与实验值更加吻合.综合考虑后发现Blake模型与实验值的偏差较Kistler模型在整体上更小,细节吻合较好,验证了模型的可靠性。

The impact characteristics of water droplet on superhydrophobic carbon nanotube（CNT）arrays have been experimently studied at different Weber（ We） numbers. Also, a numerical simulation was performed to investigate the droplet impingement based on an improved level-set method in conjunction with two dynamic contact angle models（namely Kistler model and Blake model）. The experimental and numerical results were compared and showed in an acceptable agreement during the whole spreading-receding-bounding process at the Weber number range of 1.4 to 110. In the droplet spreading stage, the numerical results from Kistler model were closer to the experimental values, while Blake model was preferable in the receding stage. The Blake model is a better choice as compared with the Kistler model after comprehensive consideration, and the numerical dynamic evolution process of droplet impact based on the Blake model is quite close to the experimental results on the whole, which verifies the reliability of this model.