A molecular dynamics study of transient evaporation and condensation
A molecular dynamics study of transient evaporation and condensation
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DOI：
10.1016/j.ijheatmasstransfer.2019.119152
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发表时间：
2020-03
影响因子：
5.2
通讯作者：
Zhi Liang;A. Chandra;E. Bird;P. Keblinski
中科院分区：
文献类型：
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作者：
Zhi Liang;A. Chandra;E. Bird;P. Keblinski
我们使用分子动力学 (MD) 模拟来研究纳米通道中纯流体 Ar 的瞬态蒸发和冷凝。在 MD 模型中，流体 Ar 的蒸发和冷凝是通过纳米通道一侧固体基质中温度的突然升高或周期性变化来引发的。在这两种情况下，我们发现直接从 MD 模拟获得的瞬态蒸发和冷凝速率与 Schrage 关系式的预测非常一致。此外，我们的分析表明，纳米通道中蒸发和冷凝表面之间的瞬态传热和传质的动力学主要由蒸汽中的热和质量扩散而不是对流控制。仿真结果表明，即使在高频振荡驱动力条件下，Schrage关系也能够准确描述瞬态蒸发/冷凝过程及其速率。
We use molecular dynamics (MD) simulations to study the transient evaporation and condensation of a pure fluid Ar in a nanochannel. In the MD model, the evaporation and condensation of fluid Ar is initiated by a sudden increase of the temperature or periodically varying the temperature in the solid substrate on one side of the nanochannel. In both cases, we find the transient evaporation and condensation rates obtained directly from MD simulations are in good agreement with the predictions from the Schrage relationships. Furthermore, our analyses show that the kinetics of the transient heat and mass transfer between the evaporating and the condensing surfaces in the nanochannel are mainly controlled by heat and mass diffusion in the vapor rather than by convection. The simulation results indicate that the Schrage relationships are capable of accurately describing the transient evaporation/condensation processes and their rates even under a high-frequency oscillatory driving force condition.