Knocking combustion in spark-ignition engines

Improving fuel efficiency with laser surface textured piston rings

A proper tire friction model is essential to model overall vehicle dynamics for simulation, analysis, or control purposes since a ground vehicle's motion is primarily determined by the friction forces transferred from roads via tires. Motivated by the developments of high-performance antilock brake systems (ABSs), traction control, and steering systems, significant research efforts had been put into tire/road friction modeling during the past 40 years. In this paper, a review of recent developments and trends in this area is presented, with attempts to provide a broad perspective of the initiatives and multidisciplinary techniques for related research. Different longitudinal, lateral, and integrated tire/road friction models are examined. The associated friction-situation monitoring and control synthesis are discussed with a special emphasis on ABS design

Integrated longitudinal and lateral tire/road friction modeling and monitoring for vehicle motion control

Surface Texturing in Machine Elements − A Critical Discussion for Rolling and Sliding Contacts

Tribology of piston compression ring conjunction under transient thermal mixed regime of lubrication

Time-Frequency Analysis of Single-Point Engine-Block Vibration Measurements for Multiple Excitation-Event Identification

This paper provides a detailed analysis of the compression ring—bore/liner conjunction. The analysis includes ring—bore conformability and global in-plane deformation of ring fitted in situ. The analysis for fitted ring in an out-of-round bore shows very good agreement with precise measurements, using a coordinate measuring machine. The analysis also includes the lubricated conjunction under a transient regime of lubrication, taking into account combined elastohydrodynamics and asperity interactions. The transient nature of the tribological conjunction has been demonstrated, particularly the prevalent mixed/boundary regime of lubrication at the top and bottom dead centres.The analysis is applied to a high performance motorbike engine subjected to very high impact loads and engine speeds of the order of 13 000 r/min. Furthermore, the predictions of the model show good conformance to the measurements of friction reported by other research workers.

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Tribology of the ring—bore conjunction subject to a mixed regime of lubrication

The paper describes the importance of reducing frictional losses in internal combustion (IC) engines, thereby improving engine efficiency. One of the main sources contributing significantly to engine friction is the interaction between the piston compression and oil rings and the cylinder bore/liner. Improving the tribological performance in these conjunctions has the greatest potential for performance improvement in the IC engine. Traditionally, the approaches used to tackle this problem have relied heavily on empirical engineering judgement. These have resulted in many inconclusive studies, involving a large number of alternatives, including the introduction of cylinder liners with surface modification work and/or with special coatings. This paper highlights a fundamental investigation of surface modification and coating and its impact on frictional performance. The study combines numerical and experimental approaches. Very good agreement is found between the conclusions of numerical predictions and those of engine test bed work.

/pdf/in-cylinder-friction-reduction-using-a-surface-finish-21rgf8plmy.pdf

In-Cylinder Friction Reduction Using a Surface Finish Optimization Technique

This article provides solution for isothermal mixed hydrodynamic conjunction of the compression ring to cylinder liner. This is obtained using the average flow model representation of Reynolds equa...

/pdf/the-influence-of-piston-ring-geometry-and-topography-on-53h3hccx3f.pdf

Paul King

Papers

Tribology of piston compression ring conjunction under transient thermal mixed regime of lubrication

Time-Frequency Analysis of Single-Point Engine-Block Vibration Measurements for Multiple Excitation-Event Identification

Tribology of the ring—bore conjunction subject to a mixed regime of lubrication

In-Cylinder Friction Reduction Using a Surface Finish Optimization Technique

The influence of piston ring geometry and topography on friction