The interaction between tribology and emissions under real driving conditions (RDE)

Zusammenfassung

On the basis of future emission requirements, in particular under the boundary conditions of the RDE legislation, the development, validation and approval requirements will significantly increase.

In this context, the optimization of the tribological system piston, piston ring and cylinder liner in order to minimize oil consumption and frictional losses is in the focus. These partial opposing objectives require a detailed analysis of the functional behavior, taking into account system robustness and the assurance of the overall system with regard to the durability over lifetime.

The effects of fuels and lubricants as well as mixture formation on wear, aging and deposition effects must also be considered. Minor changes in the piston-, piston ring- and gas dynamics or the component geometries can have a significant effect on the sealing effect of the piston group and the resulting particulate and hydrocarbon emissions. Especially transient processes under real driving conditions offer a high optimization potential. The article describes the development method for the analysis and optimization of the piston group based on fundamental research and simulation calculations as well as highly dynamic measurements on the engine test stand. The possible potentials under RDE conditions are shown.