BI-PHASIC BIOMATERIAL AND ARTICULAR CARTILAGE E.Northwood , R.Kowalski and J.Fisher * Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK. +** DePuy CMW, Cornford Rd, Blackpool, England Email: [email protected] INTRODUCTION Natural articular cartilage has a unique biphasic lubrication regime [1]. Internal interstitial fluid pressure [2, 3] leads to low levels of fr...

Here we address the comments by Iverson (2016) on our recent work concerning the reduction of friction in long runout landslides. Iverson (2016) questions the veracity of our models and suggests that high basal pore fluid pressure is the dominant mechanism reducing friction in long runout landslides. The main goal of our work was to elucidate the mechanism responsible for the apparent reduction...

Surface texturing is an important approach for controlling the tribological behavior of friction pairs used in mechanical and biological engineering. In this study, by utilizing the method of three-dimensional computational fluid dynamics (CFD) simulation, the lubrication model of a friction pair with micro-dimple array was established based on the Navier-Stokes equations. The typical pressure ...

This paper refers to complex granular-fluid mixtures involved into geophysical flows, such as debris and hyper-concentrated flows. For such phenomena, the interstitial fluids play a role when they are in the viscous regime. Referring to experiments on granular-fluid mixture carried out with pressure imposed annular shear cell, we study the rheological behaviour of dense mixture involving both s...

Insects use either hairy or smooth adhesive pads to safely adhere to various kinds of surfaces. Although the two types of adhesive pads are morphologically different, they both form contact with the substrate via a thin layer of adhesive fluid. To model adhesion and friction forces generated by insect footpads often a simple "wet adhesion" model is used, in which two flat undeformable substrate...

The idea that snow avalanches might behave as granular flows, and thus be described as Coulomb fluid flows, came up very early in the scientific study of avalanches, but it is not until recently that field evidence has been provided that demonstrates the reliability of this idea. This paper aims to specify the bulk frictional behaviour of snow avalanches by seeking a universal friction law. Sin...

Centrifuging of granular material in a partially filled rotating circular tumbler occurs when particles are flung outward to form a ring of particles at the periphery of the tumbler rotating as a solid body. The critical rotation speed for centrifuging was studied experimentally in a quasi-two-dimensional tumbler as a function of particle diameter, tumbler fill fraction and interstitial fluid. ...

The irreversibility e¤ect was found not to hold in more general model than in the one considered by Arrow and Fisher [1] and Henry [7]. In this paper we try to restore this irreversibility e¤ect and we de…ne a quasi irreversibility e¤ect.

The sustainability index, waste energy ratio and improvement potential of a staggered air jet impingement on the spherical protrusions roughened absorber plate were derived for present study to evaluate exergy losses irreversibility in system. experimental analysis was carried out selected parameters: relative streamwise pitch, spanwise pitch diameter hydraulic ratio. flow Reynolds number range...

Wet friction clutches have become widely used in today’s transmissions, e.g. automatic transmissions, dual clutch transmissions, etc. It is known that the central role of this particular component is strongly determined by its friction characteristics. While a clutch is in use, degradation inevitably takes place that consequently deteriorates its friction characteristics. However, to the author...