NUMERICAL ANALYSIS ON EFFECT OF REGULAR SURFACE
TOPOGRAPHY IN NON-NEWTONIAN FLUID LUBRICATION

CHEN Haosheng  LI Yongjian  CHEN Darong  WANG Jiadao

(State Key Laboratory of Tribology, Tsinghua University, Beijing 100084)

Abstract: The Navier-Stockes equations and finite volume method are applied to solve the load capacity and drag force of an inclined slider model. The details of the flow field are acquired, and the effect of large amplitude surface topography in non-Newtonian fluid lubrication is studied. The numerical results show that the pressure mutation occurs at the edges of bulges of the surface topography. When the height of the bulges is more than 1% lubricant thickness, the height of the bulges takes an obvious effect on the lubrication results. The load capacity and the pressure drag increase as the height of the bulges increases, while the friction drag decreases and the total drag force keeps constant. When the height of the bulges is more than 10% lubricant thickness, the friction force begins to increase and the total drag force increases rapidly. The parameter of non-Newtonian fluid affects the lubrication results more greatly than the height of the bulges does, but it does little effect on the variation process of the forces under different surface topography. In practice application, to choose the lubricant with proper parameters is the key factor in the improvement of lubrication.

Key words: Surface topography Non-Newtonian fluid Hydrodynamic lubrication

CLC No: TH117 O357

高等学校博士学科点专项科研基金(20030003026)和国家自然科学基金(50475018, 50505020)资助项目. Received 20060812, received in revised form 20070320