Numerical Analysis on the Effect of Transverse Surface Roughness in Non-Newtonian Fluid Lubrication

To analyze non-Newtonian fluid lubrication with the effect of large surface roughness amplitude, Navier-Stokes equation is used and a finite volume method is adopted to acquire the lubrication results of an inclined slider model. The numerical results show that the pressure mutation occurs at the edges of surface roughness. When the roughness height is more than 1% lubricant thickness, the surface roughness takes an obvious effect on the lubrication results. The pressure drag increase as the roughness height increases, the friction drag decreases and the total drag force keeps constant. When the roughness height is more than 10% lubricant thickness, the friction force begins to increase and the total drag force increases rapidly. Non-Newtonian fluid affects the lubrication results more greatly than the surface roughness height does, but it does not affect the variation process caused by different surface roughness.