Revisiting soft micro-elastohydrodynamic lubrication

A FEM-based multi-scale approach for modeling radial lip seal friction

verfasst von

B. Wennehorst, G. W.G. Poll

Abstract

A finite element-based deterministic multi-scale soft micro-elastohydrodynamic radial lip seal lubrication model has been set up comprising finite deformations of the elastomer surface asperities, inter-asperity cavitation and coupling of frictional heating, lubricant film temperature and lubricant viscosity. This lubrication approach essentially relies on the assumption that the lubrication of soft rough surfaces can be described by micro- or submieron-scale soft elastohydrodynamic (soft-EHL, i.e. isoviscous-clastic) lubrication at the asperity level. The overall friction thus entirely originates from the lubricant: in addition to the viscous friction contribution of the oil-filled surface roughness (meso-scale), viscous shear stresses resulting from the thin under-asperity soft-EHL oil films (submicron-scale) contribute significantly to the overall friction. The lubrication model is set up using the FEM-based multiphysics code ELMER utilizing a hydrodynamically representative sinusoidal roughness model based on the measured micro-geometry of the seal lip surface. The computed seal friction agrees well with experimental results. Moreover, this revisited soft micro EHL mixed lubrication approach is obviously capable of giving a physically sound explanation of both lubricant film formation as well as the frictional characteristics of lubricated soft rough surfaces.

Organisationseinheit(en)

Institut für Maschinenkonstruktion und Tribologie

Typ

Aufsatz in Konferenzband

Seiten

147-159

Anzahl der Seiten

13

Publikationsdatum

2013

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Wirtschaftsingenieurwesen und Fertigungstechnik, Maschinenbau, Werkstoffmechanik, Prozesschemie und -technologie, Werkstoffwissenschaften (insg.)