Engine crank case designs for passenger car applications are based today on two main material technologies: grey cast iron and an increasing share of aluminium-based concepts. Due to the low wear resistance of aluminium, the latter concepts require a wear protective layer for the cylinder bore surface. Iron-based thermal spray coats are widely used for this purpose. The coating improves the tribological behaviour significantly, as previous studies have shown. Additionally, aluminium-based concepts offer advantages regarding engine weight and thermal management. The aim of the presented work was the discussion of these technological concepts regarding the tribological and sealing properties of the piston/bore interface. The study was carried out based on the AVL FRISC Floating Liner Engine. While the basic engine remained unchanged, the cylinder bore surface was varied. In addition to the floating liner friction measurement, the blow-by and lube oil consumption were also measured. A state-of-the-art multi-body dynamic simulation model complements the experimental study, while both simulation and measurement lead to similar conclusions.

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Current requirements for the reduction of CO2 emissions, as well as for the improvement of durability and reliability of sociotechnical systems such as passenger cars, lead to an increase in development effort in order to increase efficiency and system lifetime. Tribological systems play an essential role in the development of sociotechnical systems, but have proved to be particularly complex. The development of tribological systems, as part of the overall system under development, is an interdisciplinary effort. Involvement of solid mechanics, fluid mechanics, rheology, and many more scientific disciplines is essential to cope with the high number of nonlinear relationships, which often cause unpredictable system behavior. This paper contributes to the scientific field of tribology by introducing concepts of model‐based systems engineering for the specific case of elastohydrodynamic lubrication states. The elastohydrodynamic lubrication state of tribological system has been chosen as example to show how system models can be used to better describe the behavior of a system by connecting several specific models. In order to gain an overview of the models used in tribological system development, a system cube was used to structure the models. The system cube enabled gaps and overlapping model zones to be identified. Finally, the role of system models in development and the benefit of using system models to solve problems that cannot be solved by a single technical discipline but only in an interdisciplinary effort are discussed. An approach to connect models and methods to describe a system in an elastohydrodynamic lubrication state is presented.

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