论文标题
表面纳米结构和润湿性对池沸腾的影响：一项分子动力学研究
Effects of surface nanostructure and wettability on pool boiling: A molecular dynamics study
论文作者
论文摘要
我们研究表面拓扑，表面化学和壁过热温度对沸腾，气泡成核和生长的发作的作用，以及通过大规模MD模拟的手段可能形成绝缘蒸气膜的作用。在数值实验中，我们通过对运动活塞施加恒定力来控制系统压力。模拟表明，纳米结构的存在会触发气泡的形成，确定成核位点并促进从热基质到水的能量转移。另一方面，表面化学控制了形成的气泡的形状。但是，亲水性表面化学加速了气泡成核，但是，气泡的膨胀减速，从而推迟了蒸气膜的形成。因此，亲水表面提供了从热壁到水的更好的能量转移。通过分析系统能量，我们表明，无论墙壁拓扑和化学，都有一个壁温度最大的壁温度。
We study the role of surface topology, surface chemistry, and wall superheat temperature on the onset of boiling, bubble nucleation and growth, and the possible formation of an insulating vapour film by means of large-scale MD simulations. In the numerical experiments, we control the system pressure by imposing a constant force on a moving piston. The simulations reveal that the presence of a nanostructure triggers the bubble formation, determines the nucleation site and facilitates the energy transfer from the hot substrate to the water. The surface chemistry, on the other hand, governs the shape of the formed bubble. A hydrophilic surface chemistry accelerates the bubble nucleation, however, decelerates the bubble expansion, thus postponing the formation of the film of vapour. Therefore, a hydrophilic surface provides better energy transfer from the hot wall to the water. By analysing the system energy, we show that irrespective of wall topology and chemistry, there is a wall temperature for which the amount of transferred energy is maximum.
