We investigate non-Brownian particles suspended in a periodic shear-flow using simulations. Following Metzger and Butler [Phys. Rev. E 82, 051406 (2010)], we show that the chaotic dynamics arising from lubrication interactions are too weak to generate an observable particle dispersion. The irreversibility observed in periodic flow is dominated by contact interactions. Nonetheless, we show that ...

The Reynolds equation, which describes the lubrication effect arising through the interaction of two physical surfaces that are separated by a thin fluid film, is formulated with respect to a continuously evolving third surface that is described by a time-dependent curvilinear coordinate system. The proposed formulation essentially addresses lubrication mechanics at interfaces undergoing large ...

Thin-layer chromatography has been used to identify phospholipids extracted from canine synovial fluid, the major component (45%) being phosphatidyl choline (PC). The extracts and their components have been shown to be surface active in reducing the surface tension of water and to be readily adsorbed to hydrophilic solids, whose surfaces then become hydrophobic. These adsorbed monolayers of syn...

Hyaluronan, lubricin and phospholipids, molecules ubiquitous in synovial joints, such as hips and knees, have separately been invoked as the lubricants responsible for the remarkable lubrication of articular cartilage; but alone, these molecules cannot explain the extremely low friction at the high pressures of such joints. We find that surface-anchored hyaluronan molecules complex synergistica...

The aim of this paper is to propose an analytical approximate squeeze-film lubrication model of the human ankle joint for a quick assessment of the synovial pressure field and the load carrying due to the squeeze motion, considering both normal and pathological behaviour. The model starts from the theory of boosted lubrication for the human articular joints lubrication (Walker, et al., 1968; Ma...

Steep wave fronts tend to develop in many regimes of lubricated, slipping flows in which waves appear. Problems of slip, spurt, fracture and extrudate distortion can be framed in terms of lubrication theory with paradigms arising from the lubrication of heavy oil with water for some problems and concepts from the theory of boundary lubrication for others. In water lubricated pipelines, high pre...

We study the lubricated (wet) contact mechanics of a smooth hard cylinder sliding on a randomly rough nominally flat surface of a linear viscoelastic solid. We calculate the rolling and sliding friction, and study the transition from the boundary lubrication to the elasto-hydrodynamic lubrication regime. For the viscoelastic contact the minimum (average) separation does not monotonically increa...

FRICTION AND LUBRICATION in sheet metal forming are influenced by such parameters as material properties, surface finish, temperature, sliding velocity, contact pressure, and lubricant characteristics. The parameters that affect friction and lubrication are schematically shown in Fig. 7.1. Depending on these parameters, the performance of a lubricant and the coefficient of friction (COF) vary. ...

Contents 1. Introduction 2. Stress-induced lubricant degradation 3. Basic equations governing the fluid elastohydrodynamic lubrication (EHL) of line and point contacts 3.1. Equations of fluid motion 3.2. Contact surface displacements in line and point lubricated contacts 4. Steady isothermal EHL problems for lightly loaded non-conformal line contacts 5. Steady isothermal EHL problems for heavil...