Simulation of the Piston and Piston Ring Dynamic 2001-01-3368

All reciprocating engines from the first Diesel engine to turbocharged formula 1 engines require a sealing of the combustion chamber. This sealing is realized by the compression rings. Today a set of two compression rings and one oil control ring is standard, the large variety of available solution demonstrate the continuous effort and attention paid to an optimized system performance since the first engine was started.

The complexity of the interactions with the mechanical, thermal, thermodynamic, tribologic, dynamic behavior of the piston still requires mechanical testing of the various components before release to series production. This procedure can be shortened by use of simulation models reflecting the real behavior in detail to select the most promising combinations of components and characteristics.

This paper presents the model to simulate the dynamic motion of the piston as function of the liner and piston geometry, the surface quality and the thermal and thermodynamic boundaries. The primary and secondary motion of the piston is used further as boundary to simulate the dynamic behavior of the piston rings. Again the surface of the tribologic partners is considered based on a statistical approach. The dynamic behavior is used to predict the wear rates and the blow by.

Based on the simulation model of a modern combustion engine the dynamic behavior for various operating conditions will be presented and described. This section is followed by the comparison to measurement results.

Finally an outlook will be made for the further development of the piston group in modern combustion engines with respect to increasing engine performance, reduced fuel consumption and low emission levels.