亲水/疏水复合凹槽壁面上气泡成核的分子动力学模拟研究

Molecular Dynamics Study of Bubble Nucleation on the Substrate With a Hydrophilic-hydrophobic Composite Groove

本文采用分子动力学方法研究亲水/疏水性复合壁面凹槽壁面对气泡成核的影响,并对比其与单一亲水性或单一疏水性凹槽壁面在成核行为、成核率等方面的差异。结果表明:液体氩在不同润湿性凹槽壁面加热下均产生明显的气核,但成核现象存在差异;固–液传热效率随着亲水性的增强而提高,而壁面附近液体原子所受的势能束缚随疏水性增强而降低,亲水/疏水性复合壁面凹槽可利用其亲水侧高效传热与疏水侧低相变能垒的优势,提高被加热液体的成核率。

In this paper,the molecular dynamics method is conducted to study the effects of hydrophilic-hydrophobic composite groove substrate on bubble nucleation.The differences in nucleation behavior and nucleation rate are compared between hydrophilic-hydrophobic composite groove substrate and the groove substrate with uniform hydrophilicity and hydrophobicity,respectively.The results show that a visible bubble nucleus appears on the substrates with different wettability conditions after a period of heating on liquid argon,but the nucleation behaviors are different.The heat transfer efficiency of solid-liquid increases with the enhancement of hydrophilicity,while the potential barrier of nucleation for liquid atoms in the vicinity of the substrate decreases with the enhancement of hydrophobicity.The hydrophilic-hydrophobic composite groove has characteristics of high heat transfer efficiency on the hydrophilic side and low nucleation potential barrier on the hydrophobic side,leading to the promotion of bubble nucleation.