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The development of a modern internal combustion engine can be characterized by three main trends: durability increase, emission reduction, and fuel economy improvement. Ring pack design addresses all of these issues. The ring behavior affects the blow-by past the ring pack, the oil film left on the cylinder liner, the friction force between the liner and the ring, and the wear of the ring and the cylinder liner. In order to predict these phenomena, the prediction of inter-ring gas flow and ring behavior, especially ring motion and ring twist about ring centroid, is needed. This paper presents the results of the modeling of 3-dimensional ring twist and its influence on ring performance and blow-by. The TWIST program includes a 3-dimensional beam model of a piston ring.

All modern automotive automatic transmissions require the use of a torque converter to allow for the transmission of torque from the engine to the drivetrain. Although they are commonly used throughout the automotive industry, there is little understanding of the internal flows within the torque converter. An experimental study has been conducted to reveal the internal flow characteristics within a production torque converter using Laser Doppler Velocimetry (LDV) under the operating conditions. LDV measurements were conducted on the planes between impeller blades, and the gap between the impeller and turbine blades. The study showed that the internal flow is highly complex and the difference in rotor speeds between the impeller and turbine compound the flow effects. Transmission oil flows in the planes at the impeller exit and gap region were affected by the turbine blade as it passed.

Increasing oil prices and more stringent emission laws require an improved efficiency from future automotive engines. Additionally, the competition of the automotive market demands longer service intervals and engine life-times. A potential to decrease the specific fuel consumption and improve specific volume is offered by means of increasing engine speed and maximum cylinder pressure. Hence, the mechanical stress on the tribological system including the piston, piston rings, cylinder liner, are increased and the reliability decreases. The objective of this research is the development of a mathematical model implemented in software, which can deliver a prediction of piston ring wear in internal combustion engines. The program has been applied to a top compression piston ring of a turbo charged Diesel engine at WOT operation conditions.

The flow inside a combustion engine is highly complex and varies significantly with small changes in the engine configuration. For a long time IC-engine researchers have tried to predict the major mean flow patterns inside close-to-production engine setups. During the last decades computational fluid dynamics (CFD) has significantly contributed to the engine development process. Hence, significant research has focussed on the comparison of modeled and measured flows in IC engines. However, according to the knowledge of the authors, this study is the first fully three-dimensional (3-D), modeling and measurement effort that has evaluated the vast majority of the displacement volume by using an identical engine geometry. With improved, non-intrusive, 3-D velocity measurement technology, the vast majority of the cylinder displacement was explored and compared with Star-CD modeling results at the same locations.

The ring-pack behavior in a modern gasoline engine represent complicated phenomena. The process of ring pack design consists of two stages: understanding the physical behavior and design synthesis on the systematic manner. Computer models give an inside on the physical processes associated with the ring-pack behavior. Mathematical optimization techniques provide the tools for design synthesis on the systematic way based on an optimal criteria. The mathematical optimization technique was developed and applied to ring pack design synthesis. When applied to the existing engine ring-pack designs, the optimized results indicated the potential for significant reduction in blow-by through the ring-pack by optimizing ring pack geometry. The optimization results were compared with the original ring pack designs for two gasoline engines for a wide range of operating conditions.