The air cushioning effect in the gap between an almost inviscid body of water and a nearby solid wall (or another body of water) is studied theoretically and is found to depend on predominantly lubricating forces in the air, in certain applications. The situation in which the density and viscosity in air are taken as small compared with those in water is investigated. In this situation potentia...

A mathematical model for the evolution of a thin film in an interior corner region is presented. The model is based on the idea that the film can be considered thin everywhere in the η-direction if viewed in the new coordinate system ξ = x − y, η=2xy. Lubrication theory is applied to the governing equations written in this coordinate system. The exact integration of the mass conservation equati...

(1) An apparatus has been constructed to measure the coefficient of friction of synovial membrane against a glass slider. (2) Provision was made to vary the load on the specimens. (3) The coefficient of friction varied from 0-006 to 0-07. (4) A presentation similar to that used in the Sommerfeld analysis of journal bearings indicated that in these experiments synovial membrane was lubricated in...

We develop a scaling model relating the friction forces between two polyelectrolyte brushes sliding over each other to the separation between grafted surfaces, number of monomers and charges per chain, grafting density of chains, and solvent quality. We demonstrate that the lateral force between brushes increases upon compression, but to a lesser extent than the normal force. The shear stress a...

Ferrofluids (FFs) are stable colloidal suspensions composed of single-domain magnetic nanoparticles dispersed in a carrier liquid. And it is an intelligent material, exhibiting normal liquid behaviour coupled with superparamagnetic properties. Since the properties and the location of these fluids can easily be influenced by a magnetic field, FFs have recently attracted many scientific, industri...

Tribotechnical diagnostics as an integrated conception deals with the assessment of lubricants properties, monitoring of behaviour and consequences of the lubricant degradation process during its work in the machine lubrication system. For tribodiagnostic of friction pairs of aircraft engine are used three basic methods dealing with the qualitative and quantitative determination of wear particl...

We use dynamical systems theory to construct the normal form of the Navier–Stokes equations for the flow of a thin layer of fluid upon a solid substrate. The normal form equations illuminate the fluid dynamics by decoupling the long-term flow of interest from the rapid viscous decay of the transient shear modes. The normal form clearly shows the centre manifold of the lubrication model and show...

Micro lubrication or also known as minimum quantity lubrication (MQL) serves as an alternative to flood cooling by reducing the volume of cutting fluid used in the machining process; but not without significant health concerns. Flood cooling is primarily used to cool and lubricate the cutting tool and work piece interface during machining process. The adverse health effects caused by the use of...

We consider constant volume thin film slurries on an incline. Clear fluids in this geometry are known to have a front position that moves according to a t scaling law, based on similarity solution analysis [Huppert, Nature, 1982]. We investigate the same dynamics for particle laden flow using a recently proposed lubrication model for the slurry and physical experiments. Our analysis includes th...