固液界面热阻的温度依赖特性模拟研究

Numerical Study of the Effects of System Temperature on Heat Transfer at the Solid-Liquid Interface

基于非平衡态分子动力学模拟方法,研究了系统温度及固液结合强度对固液界面传热的影响规律。模拟结果表明,固液界面热阻随着系统温度的升高而降低,并且亲水性界面的界面热阻温度依赖性较弱。基于微观热流密度计算式的分析表明,随着系统温度升高,动能项和维里项的贡献均逐渐增大,因而固液界面传热增强,但是动能项占比逐渐增大,维里项占比逐渐降低;随着固液结合强度逐渐增大,界面吸附效应增强,维里项贡献明显增大,这是较强的固液相互作用能够强化界面传热的主要原因。

In the present paper,the effect of system temperature and solid-liquid bond strength on the thermal transport has been investigated based on the non-equilibrium molecular dynamics simulations.It is revealed that the interfacial thermal resistance decreases with increasing temperature,and the interfacial thermal resistance of the hydrophilic interface has a weak temperature dependence.The interfacial thermal transport mechanism is analyzed based on the microscale calculation formula of the heat flux.With increasing temperature,both the contributions by the kinetic and virial term can be enhanced.The proportion of the kinetic term increases,while the proportion of the virial term decreases with increasing temperature.For strong interfacial couplings,the virial term can be enhanced,which is the dominate mechanism for the enhanced interfacial heat transfer.