建立了近壁面区池沸腾系统分子动力学模型,将壁面对流体的作用作为附加力引入,从成核位置、平均分子动能和界面接触热阻三个方面研究了壁面润湿性对液氩沸腾核化的影响规律和机理。模拟结果表明,壁面润湿性越强,壁面对流体分子的束缚作用越强,成核位置离壁面越远;壁面润湿性较强时紧靠壁面区域的平均分子动能明显高于远离壁面处的平均分子动能,润湿性弱时沿垂直壁面方向分子动能变化不明显;对于润湿性较强的壁面,界面接触热阻较大,不利于沸腾核化。
We established a gas-liquid-solid three phase pool boiling system from molecular dynamics insight,introducing the interactions between the wall and the fluid as an additional force.The effects of wall wettability on the boiling nucleation were studied from three aspects of the nucleation position,the average kinetic energy and the interface contact thermal resistance.The results show that strong surface wettability means strong constraint to the near surface molecules and gas nuclear position is farther from the surface.For stronger surface wettability,the molecular average kinetic energy for the molecules adjacent to the surface is significantly larger than that for the molecules far from the surface,for weaker surface wettability,molecular kinetic energy has a uniform distribution in the vertical direction of the wall.As increasing the surface wettability the interface contact thermal resistance increases and accordingly the boiling nucleation is weakened.