... quantitatively observed during the upsetting of cylinders with a central conical dent using the new fluorescence direct observation apparatus developed by the authors. Moreover, the permeation phenomena were estimated using a rigid-plastic finite element analysis model incorporating the compressibility...

... surprising as one would expect more problems in the case of air due to compressibility and Knudsen number effects ( 16 ). Likewise, films are generally thinner and forces lower, increasing the likelihood of experimental errors. Yet, the large discrepancy between experimental and theoretical data is observed...

... to those with compliant coatings under the same contact conditions. For stiffer coatings, the values of the von Mises stress and compressive surface stress increase and the positions of maximum von Mises stress move up to the surface; meanwhile, the distributions of the compressive stress become asymmetric...

... and distribution for inset materials with various stress-strain behaviors. Measurements of permanent deformation and load-deflection behavior of specimens held under applied compression over time showed dependence of the amount of permanent deformation on strain energy. Design rules were extracted from results...

... gained attention in the field of EHL, along with Tait’s equation of state for compressibility. The well-established Carreau viscosity model has been used to describe the simple shear-thinning encountered in EHL. The simulation results have been used to develop an approximate equation for traction...

...Thomas Geike; Valentin L. Popov The negative squeeze lubrication problem is investigated by means of numerical simulations that account for the dynamics of vaporization. The model is based on bubble dynamics, governed by the Rayleigh–Plesset equation, and the Reynolds equation for compressible...

... compressibility is an exception. 01 04 2008 17 06 2008 07 08 2008 compressibility elastodynamics friction hydrodynamics liquid films lubricants lubrication organic compounds viscosity EHL elastohydrodynamics rheology high pressure viscosity The field...

...Roger Tuomas; Ove Isaksson A high-pressure chamber is used to study lubricant compressibility when refrigeration oil is diluted by refrigerant. The tested lubricant in this work is a POE (polyol ester) oil, POE diluted with nonchlorinated (HFC) refrigerant R-134a, a naphthenic mineral oil...

...S. Kondo; R. S. Sayles; M. J. S. Lowe The paper describes an experimental technique combining optical interferometry and ultrasonic attenuation to measure the bulk modulus (compressibility) and film thickness profiles of oil and grease films entrapped between a stationary steel ball and a sapphire...

...D. E. A. van Odyck; C. H. Venner A multigrid numerical solution algorithm has been developed for the laminar (Stokes) flow of a compressible medium in a thin film. The solver has been applied to two model problems each representative of lubrication problems in a specific way. For both problems...

..., the maximum compressive forces attained during the contact process far exceed the predictions of Hertzian contact theory. The discrepancy between results of this simulation and those of the static-equilibrium analytical and numerical models indicate that dynamic interactions play a significant role...

...Coda H. T. Pan, Engineering Consultant, The pressurization-flow characteristic of a helical viscous compressor is basic to the design of precision air bearings and non-contact gas seals which make use of the spiral-grooved surface feature. The method of Compressible Narrow Groove Analysis (CNGA...