A Comparison of the Roughness Regimes in Hydrodynamic Lubrication

作者：Fabricius John^*; Tsandzana Afonso; Perez Rafols Francesc; Wall Peter

来源：Journal of Tribology-Transactions of the ASME, 2017, 139(5): 051702.

DOI：10.1115/1.4035868

This work relates to previous studies concerning the asymptotic behavior of Stokes flow in a narrow gap between two surfaces in relative motion. It is assumed that one of the surfaces is rough, with small roughness wavelength mu, so that the film thickness h becomes rapidly oscillating. Depending on the limit of the ratio h/mu, denoted as lambda, three different lubrication regimes exist: Reynolds roughness (lambda = 0), Stokes roughness (0< lambda< infinity), and high-frequency roughness (lambda = infinity). In each regime, the pressure field is governed by a generalized Reynolds equation, whose coefficients (so-called flow factors) depend on lambda. To investigate the accuracy and applicability of the limit regimes, we compute the Stokes flow factors for various roughness patterns by varying the parameter lambda. The results show that there are realistic surface textures for which the Reynolds roughness is not accurate and the Stokes roughness must be used instead.

• 出版日期2017-9