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In the paper production, doctor (scraping) blades are placed in contact with press rolls during wet pressing so as to purge the surface of the rolls from processing water, contamination and stickies. The contact is achieved by mounting the blade on a holder, which is tilted around a rotation axis until the blade tip contacts with the roll. The contact force is determined by the supply pressure of the air forced through the tube that is placed at the bottom of the holder. Owing to contact, the blade wears off and needs to be replaced periodically. Our aim is to optimise the cleaning performance of the system by modelling the tribological contact between the doctor blade and press roll in order to achieve an optimum cleaning performance, thus increasing the blade lifetime and reducing energy consumption. The model is susceptible to an inextensive numerical evaluation as compared to that of a more advanced modelling approach, e.g. in terms of a full finite element analysis of the beam deflection. A first comparison with experimental findings is encouraging. [ABSTRACT FROM AUTHOR]

Confronted with the contemporary challenges of maximising energy efficiency with minimal impact on the environment, the automotive industry has developed various technologies to tackle them. Most of these technologies, however, have wider implications on the tribological performance of the automotive engines due to resultant soot build-up. This paper reviews the effects that attempts by stakeholders to satisfy requirements for reduced fuel consumption, reduced emissions and extended service intervals have had on increasing soot levels to an extent that can lead to engine component failure. Three areas have been identified that have either not been explored or not widely explored in the study of automotive soot namely: numerical simulation and modelling of soot wear, soot effects on wear of actual engine components and the wear and friction performance of non-metallic materials used in internal combustion engines. A paper-grading system is also utilised to present an overview of how sooty oil-related research covers various areas. [ABSTRACT FROM AUTHOR]

The engine power losses and sealing behaviour through compression rings have become a priority for engine manufactures in view of future stringent emissions standards. Historically, compression rings have great application in small road vehicles and high-performance engines. The sealing behaviour of the compression ring has a significant effect on generated friction. Therefore, the lubrication conditions in the compression ring-liner conjunction should be addressed. This study comprises ring-liner mixed hydrodynamics using a two-phase flow and a gas blow-by model. This is implemented to investigate the characteristics of a high-performance top compression ring for different engine conditions. Low, medium, and high driving speeds are examined according to world-wide harmonized light vehicles test cycle. Additionally, the impact of lubricant temperature and compression ring width on power loss and fuel consumption are investigated to display the better engine performance. [ABSTRACT FROM AUTHOR]