Lubrication plays an important role in the clinical performance of the ceramic-on-ceramic (CoC) hip implant in terms of reducing wear and avoiding squeaking. All the previous lubrication analyses of CoC hip implants assumed that synovial fluid was sufficiently supplied to the contact area. The aim of this study was to investigate the lubrication performance of the CoC hip implant under starved ...

We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction...

Reciprocating compressors are most common type of compressor and most flexible machine to handle wide capacity and condition swings. They offer a most efficient method of gas compressing. They are vital machines in various units of industrial plants. In this paper advanced technologies and latest configurations and methods regarding condition monitoring, performance, flow management, capacity c...

The elastohydrodynanlic force on two slightly defornlable bodies approaching one another head on is calculated in the limit of small gap sizes and small defornlations by combining Hertz's theory of deformation and lubrication theory. An expression for the lubrication force analytical in the deformation and gap size is obtained. The effect of the gap size, the elasticity and the velocity of appr...

In this work, CFD simulations of an air-water bubbling column were performed and validated with experimental data. The superficial gas velocities used for the experiments were 0.019 and 0.038 m/s and were considered as an homogeneous regime. The former involves simpler physics when compared to a heterogeneous regime where the superficial velocities are higher. In order to simulate the system, a...

The tribology of 2-methacryloyloxyethyl phosphorylcholine monolayers in water is studied using molecular dynamics simulations. Our results show two distinct shear regimes where the first is dominated by hydration lubrication, exhibiting near zero friction coefficients, and the second by chain-chain interactions, resembling monomer-supported lubrication. These results provide insight into the hy...

Understanding how grain and powder lubrication affect rock friction and fracture dilation, and how microscopic fractures develop according to fault activation may directly improve our capabilities in exploration and stimulation of oil and gas reservoirs. Using a novel rotary shear testing apparatus specifically designed and assembled to conduct experiments inside an X-ray micro computed tomogra...

The hydrodynamic lubrication of the teeth of the gaterotor in a single screw compressor differs from the well-known lubrication of bearings. This difference can be related to the constrained fluid film geometry and the conditions of the lubrication. Under these circumstances the convective fluid inertia will affect the performance of the lubrication. During meshing, variations of the filmgeomet...