Layout and Optimization of a Piston Ring-pack for AUDI V6 SI-engine 2012-01-1623
The use of modern simulation tools in the engine product development process is explained using the layout of a piston and its piston ring-pack of AUDI V6 SI-engine as example. Based on the requirements for piston rings in a SI-engine the possible trade-offs are explained. A base layout for a ring-pack for the specific engine is presented. Further the validity of the simulation model is rated as the simulation output is compared to actual dynamometer measurements of the blow-by map of the engine. Additionally a test setup is presented, which measures piston ring movement and the pressures between the rings and in the ring grooves. Also these measurement results are compared to the simulation.
Using DOE (design of experiments) on the base layout potentials for optimization are shown and applied. To identify the positive effects in the engine pistons with piston rings are fabricated in accordance with the DOE recommendations. The following dynamometer measurements are then compared to the simulation. The test results follow the simulation results closely.
To successfully adjust the piston ring-pack to the engine requirements and find potential for optimization, it is necessary to understand the system piston and ring-pack in every detail. This can only be achieved by the use of simulation tools, as the system, composing piston and piston rings, is highly dynamic. Because of the very complex dynamics of the system it requires understanding of the details. Therefore a simulation approach in close cooperation with engine tests is chosen.