Analysis of the effect of surface topography on lubrication using heterogeneous multiscale method

摘要

In this paper, flow factors considering the roughness of the different orientation angles and different wavelengths are obtained from the derived form of the homogenization coefficient, which is calculated by a heterogeneous multiscale inverse approach. The influence of anisotropic roughness on the flow factors is investigated. When the angle is equal to 45 degrees, the span flow is maximum. The flow factor curves happen to overlap when the wavelength ratio is less than 4 with double cosine roughness. To verify the flow factors, film pressures are calculated by a finite element heterogeneous multiscale method (FE-HMM) without considering the flow factors. Then, by comparing the results with solutions of a finite difference method, the FE-HMM method gets the results that are needed, and with a shorter time of calculation. The pressure curve is greatest when the orientation angle is 45 degrees with a double cosine roughness, which is caused by the asperity number and the span flow. The pressure distributions of the cosine roughness and double cosine roughness are different as the orientation angle changes.