• CN:11-2187/TH
  • ISSN:0577-6686

›› 2004, Vol. 40 ›› Issue (9): 1-5.

• 论文 •    下一篇

有序薄膜润滑的速度场

张朝辉;雒建斌;温诗铸   

  1. 北京交通大学机电学院;清华大学摩擦学国家重点实验室
  • 发布日期:2004-09-15

VELOCITY FIELD IN THIN FILM LUBRICATION LUBRICATED WITH THE ORDERED MOLECULES

Zhang Chaohui;Luo Jianbin;Wen Shizhu   

  1. School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University State of Key Laboratory of Tribology,Tsinghua University
  • Published:2004-09-15

摘要: 基于有序膜分子模型分析薄膜润滑中的速度场分布。薄膜润滑中有序膜分子的取向与向列相液晶分子有类似性,可用“向矢”表示。利用液晶理论可以分析薄膜润滑的速度场和润滑剂分子的取向,为分析薄膜润滑的特性提供依据。薄膜润滑区别于弹流润滑之处在于有序膜分子的弹性。粘弹比可以很好地表征这种差异。给出了不同粘弹比下的“向矢”角度和等效粘度的分布情况以及速度场的分布情况。

关键词: 薄膜润滑, 速度场, 液晶, 有序分子

Abstract: The velocity field of thin film lubrication (TFL) lubricated with the ordered molecules is investigated. TFL is essentially a lubrication regime in which the ordered molecules play a dominant role. The orientation of ordered molecules is similar to that of nematic liquid crystal molecules and subsequently a vector, the director, can describe it. The velocity field and molecules’ ordering can be analyzed with the use of theories of nematic liq-uid crystals, and consequently the properties of lubrication with ordered molecules could be obtained. The differences, however, because the alignments are resulted from the surface forces of the solid walls, express in that the pertinent Leslie coefficients are not prescribed as the nematics are. The discrepancy of TFL from EHL comes from the elasticity of the ordered molecules. The viscosity-to-elasticity ratio can account for it well. The distributions of the director at various viscosity-to-elasticity ratios, as well as the effective viscosity, are presented. The corresponding velocity field is also presented. The research exhibits the feasibility of using the liquid crystals theory in TFL analyzing.

Key words: Liquid crystal, Ordered molecules, Thin film lubrication, Velocity field

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