低温下纳通道中纳米流体的传热机理

基于平衡分子动力学方法,引入含有量子修正项的WK势能模型,研究了低温条件下含有铜纳米颗粒的氦纳米流体在纳米尺度通道中的传热机理.通过比较原子势能、动能和碰撞能及加入纳米颗粒对热导率的影响,揭示出纳米颗粒与系统所有原子的相互作用势对纳米流体热导率贡献最大.分析热导率矢量随计算时间的收敛曲线,发现流道方向的热导率远大于壁面方向,热导率呈现出各向异性特征,深入的研究最终阐明了产生这一现象的物理机理.

Mechanism of heat transfer enhancement of nanofluids in a nano-channel at low temperature

Mechanism of heat transfer enhancement of base fluid helium containing copper nanoparticles flowing in a nano-channel at low temperature is obtained based on the equilibrium molecular dynamics method by introducing the WK potential function with quantum correction items.The results show that the interaction between the nanoparticals’ atoms and all atoms plays the most important role in the enhancement of the thermal conductivity by comparing with the influence of potential energy,kinetic energy,collision energy and adding of nanoparticle.The converging curves of thermal conductivty vectors display that it is greatly bigger along the flowing direction than that along the channel height’s direction.The physical mechanism which causes such interesting phenomena of anisotropic characteristic is elucidated.