A Multiscale Framework for EHL and Micro-EHL

作者：Gao Leiming^*; Hewson Rob

来源：Tribology Transactions, 2012, 55(6): 713-722.

DOI：10.1080/10402004.2012.656882

• Multiscale Method
• Micro-EHL
• Surface Roughness Analysis and Models
• Tilting-Pad Bearings

In this article, a heterogeneous multiscale method is introduced to analyze the microelastohydrodynamic lubrication (micro-EHL) of bearings with topological features. Two scales are adopted in the analysis: the large-scale simulations describe the entire bearing domain, and the small-scale simulations describe the fluidstructure interaction (FSI) at the small-scale features. Conservation of mass and momentum of the lubricant and the bearing%26apos;s elastic deformation are solved for. The relationship between the pressure gradient and mass flow is obtained from homogenized small-scale FSI simulations and applied on a global scale via a scattered data interpolation method. When the micro structure is periodic the exact model at micro scale is replaced by an effective derived equation, i.e., homogenized model. The elastic deformation of the textured bearing surface is addressed at both the large and small scales, by decomposing the displacement influence matrix into the diagonal terms and nondiagonal terms (sorted at the small scale and large scale, respectively). The multiscale method was demonstrated as being capable of modeling the global pressure and film thickness for a bearing with surface texture while maintaining the accuracy of the small-scale modeling features. The illustrative geometry was that of a linear converging pad bearing in two dimensions. The solutions were compared with those obtained using lubrication theory for the smooth surface case, and good agreement was obtained. The method was then demonstrated for geometries incorporating topographical features.

• 出版日期2012-11-1