纳米ZnO对正辛烷边界润滑摩擦特性的分子动力学研究  

Molecular Dynamics Study on Boundary Lubrication Properties of N-octane with Nano ZnO

作　　者：侯献军[1,2] 安恒 江华[1,2] HOU Xianjun;AN Heng;JIANG Hua(Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan University of Technology,Wuhan Hubei 430070,China;Hubei Research Center for New Energy&Intelligent Connected Vehicle,Wuhan University of Technology,Wuhan Hubei 430070,China)

机构地区：[1]武汉理工大学现代汽车零部件技术湖北省重点实验室,湖北武汉430070 [2]武汉理工大学湖北省新能源与智能网联车工程技术研究中心,湖北武汉430070

出　　处：《润滑与密封》2024年第9期1-9,共9页Lubrication Engineering

基　　金：国家自然科学基金项目(51875423)。

摘　　要：为了研究纳米ZnO对正辛烷边界润滑性能的改善机制,在考虑边界粗糙度的情况下,建立具备凸峰的分子动力学边界润滑模型,研究25~400 MPa负载条件下基础液与ZnO纳米流体的密度分布与径向分布函数,分析基础液与ZnO纳米流体在不同正压力下的摩擦特性。结果表明:基础液与纳米流体在不同正压力下都出现了密度分层,且正压力越大,分层越明显;纳米ZnO的加入会改变基础液的结构,提升承载能力;纳米流体能降低剪切过程中摩擦表面应力应变,并减小晶格畸变的程度;质量分数1.636%的纳米ZnO流体界面模型的摩擦因数为0.078 1,较基础液界面模型减小了47.4%,说明纳米ZnO对正辛烷边界润滑界面具有显著的减摩作用。In order to study the mechanism of improving the boundary lubrication performance n-octane by nano ZnO,by considering boundary roughness,a molecular dynamics boundary lubrication model with convex peaks was established.The density distribution and radial distribution function of base liquid and ZnO nano-fluid under a loading condition of 25 MPa to 400 MPa,and the friction characteristics of the base liquid and ZnO nano-fluid under different positive pressures were analyzed.The results show that the density layers occur in both base liquid and nano-fluid under different positive pressures,the greater the positive pressure,the more obvious the layering.The addition of nano ZnO will change the structure of the base liquid and enhance its bearing capacity.Nano-fluids can reduce the stress and strain of friction surface and reduce the degree of lattice distortion during shearing.The friction coefficient of the interface model of the nano-fluid with a mass fraction of 1.636%ZnO is 0.0781,which is reduced by 47.4%compared with the interface model of base liquid interface,indicating that nano ZnO has a significant friction reducing effect on the n-octane boundary lubrication interface.

关 键 词：边界润滑 分子动力学 烷烃 纳米氧化锌 纳米流体 

分 类 号：TH117.1[机械工程—机械设计及理论] TE626.3[石油与天然气工程—油气加工工程]