浸润度对低温下气膜产生的影响

Effect of Wettability on the Vapor Film Formation on the Solid Surface at a Low Temperature

针对气膜在沸腾过程中的低热导率以及能够降低流体流动阻力的特点,应用分子动力学模拟的方法在等温等压系综下模拟了气膜的形成过程,在较低的温度下得到了气膜.通过改变固液界面的接触角来改变固液界面的浸润度,进一步影响气膜的形成.结果表明,超疏水性固体壁面明显能够增强气膜形成,在较低温度下,一般的疏水性界面不能形成气膜,而超疏水性界面能够在较短时间内形成气膜,既可以减小流体流动阻力,又可以防止器件表面温度过高而烧坏.

With the low thermal conductivity of the vapor film in boling and its ability to reduce the fluid flow resistance ,the formation of the vapor film was simulated by the method of molecular dynamics （MD） under the NPT （isothermal and isotonic system ） ensemble ,with the vapor film obtained at the lower temperature .The effect of the contact angle of the solid surface on the vapor films formation on the solid surface was investigated because it can change the wettability of the solid-liquid surface .The results show that the superhydrophobic solid surface can significantly enhance the film formation .At the lower temperature ,vapor films can not form on the normal hydrophobic surface but can form on the superhydrophobic surface in a short time , not only reducing the fluid flow resistance , but also preventing the device surface from burning out because of too high temperature .