纳米尺度水薄膜液-气相变分子动力学模拟

采用分子动力学模拟,研究了纳米尺度水薄膜厚度和系统温度对液-气相变蒸发率的影响.模拟了水薄膜厚度为2nm时,温度(375~425K)对相变蒸发率的影响;同时模拟了温度400K条件下,水薄膜厚度(2、3、4nm)对相变蒸发率的影响.结果表明:相同水薄膜厚度下蒸发率随着温度的升高而增大,相同温度下蒸发率随水薄膜厚度的增大而增大,蒸发率随时间呈指数形式递减.相关结果可为微热管及其他依靠内部液体相变传热的散热器件设计提供参考.

Molecular dynamics simulation of liquid-vapor phase-change for nanoscale water films

The influence of the thickness of nanoscale water film and the system temperature on the evaporation rate of the liquid-vapor phase-change is studied using the molecular dynamics (MD) simulation. The influence of temperature (375-425 K) on the evaporation rate of the phase-change is simulated with the water film thickness of 2 nm. In addition, at the temperature of 400 K, the influence of the water film thickness (2, 3, 4 nm) on the evaporation rate of the phase-change is simulated. The simulation results indicate that the evaporation rate increases with temperature under the condition of the same water film thickness, the evaporation rate increases with the thickness of the water film at the same temperature and exponentially decreases with time. The related results can provide a reference for the design of heat transfer devices whose principle is based on the liquid phase-change, such as micro heat pipe.