Starved Lubrication of Elliptical EHD Contacts

Abstract

This paper focuses on the lubrication behavior of starved elliptical Elasto-HydroDynamic (EHD) contacts. Starvation is governed by the amount of lubricant available in the inlet region and can result in much thinner films than occurring under fully flooded conditions. Therefore, it would be desirable to be able to predict the onset and severity of starvation and to be able to relate film reduction directly to the operating conditions and lubricant properties. The aim of this work is to explore the influence of these parameters on starvation. A combined modeling and experimental approach has been employed. The numerical model has been developed from an earlier circular contact study [1]. In this model, the amount and distribution of the lubricant in the inlet region determines the onset of starvation and predicts the film decay in the contact. Numerical simulations for a uniform layer on the surface show that a single parameter, characteristic of the inlet length of the contact in the fully flooded regime, determines the starved behavior. Film thickness measurements under starved conditions were performed to validate this theory. For a circular contact excellent agreement was found. In theory the same mechanism applies to elliptic contacts, however, the behavior is more complicated.

Boundary Conditions for Elastohydrodynamics of Circular Point Contacts

“…The current paper is not primarily concerned with issue of starvation, although this phenomenon results as a repercussion of the use of true boundary conditions. More specific studies of lubricant film thickness under different levels of starvation have been carried out by Qian et al [47] and Damiens et al [48]. There is limitation in applied load due to the use of a toughened glass race.…”

The Influence of Surface Texturing on the Film Thickness in Starved Lubricated Parallel Sliding Contacts

“…Further, Chiu [13] and Chevalier et al [14], followed by Damiens et al [15], have theoretically studied starved lubrication. These theoretical studies were based on the work of Jakobsson and Floberg [16] and Olsson [17], who introduced the concept of "fractional film content" and derived continuity relations.…”

Cavitation induced starvation for piston-ring/liner tribological conjunction

“…This is a function of the oil film thickness to the width of the gap. Damiens et al [25] investigated the starvation effect on an elliptical contact and Venner et al [26] used a modified version of the algorithm for starved point contact conditions. An ideal ring would completely seal the combustion chamber.…”