I N T R 0 D U C T I 0 N In recent years, the application of double-flow rotary vane compressor in automotive air-conditioning systems has been increased because of its multiple cylinder characteristic. A certain problem is its high friction loss at higher speeds. The greatest amount of the friction is caused by the lubrication systems between the vane tip and the cylinder wall and between vane ...

Background: Under severe operating conditions, such as lubricant contamination, elevated temperatures and high unit loads, the hydrodynamic (HD) lubrication condition in a HD bearing may degrade and be reduced to mixed and boundary lubrication conditions, which traditional pad bearing materials (Babbitt metal) are not able to sustain. For example, Electrical Submersible Pump (ESP) systems are r...

Extensive studies have explored the dynamics of the ocular surface fluid, though theoretical investigations are typically limited to the use of the lubrication approximation, which is not guaranteed to be uniformly valid a-priori throughout the tear meniscus. However, resolving tear film behaviour within the meniscus and especially its apices is required to characterise the flow dynamics where ...

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...