基础油中金刚石纳米颗粒润滑性能和导热性能的分子动力学分析

Molecular Dynamics Analysis of Lubrication and Thermal Conductivity of Diamond Nanoparticles in Base Oil

为了研究纳米颗粒对基础油液热导率的影响,在基础油蓖麻油酸中加入不同体积分数和粒径的纳米金刚石颗粒,采用LAMMPS和分子动力学的研究方法,对粒子数密度以及粒子的径向分布规律、导热系数进行研究。结果表明:加入纳米颗粒的纳米流体的热物理性质受到多方面的影响,其中包括纳米颗粒体积分数及粒径等;随纳米粒子体积分数的提高纳米流体的热导率呈近似线性增加,随着纳米粒子粒径的减小,纳米粒子润滑膜的承载能力增强。纳米润滑膜能承受很高的外界冲击力,这有助于减小两作用面之间的摩擦,减小表面磨损;加入纳米颗粒的润滑油会减小摩擦副之间的摩擦和增强散热,提高热导率。

In order to study the effect of nanoparticles on the thermal conductivity of base oil,nano diamond particles with different volume fraction and particle size were added into castor oil,and the particle number density,radial distribution and thermal conductivity of the particles were studied by using the method of LAMMPS and molecular dynamics.The results show that the thermophysical properties of nanofluids with nanoparticles are affected by many factors,including concentration,size of nanoparticles.With the increase of the volume fraction of nanoparticles,the thermal conductivity of nanofluids increases approximately linearly.With the decrease of the size of nanoparticles,the load-carrying capacity of nanofluids is increased.The lubrication film formed by nanofluids has a high bearing capacity,which helps to reduce friction and improve surface wear.The lubricating oil with nanoparticles can reduce the friction between the friction pairs,enhance the heat dissipation and improve the thermal conductivity.