Development Process to Optimize Design and Performance of Small Gasoline Engines 2007-32-0093

The further optimization of modern gasoline engines needs sophisticated development tools to meet future emission legislation and fuel consumption targets. The multi-dimensional optimization process has to take into account parameters like

• Cylinder head and port flow design
• Valve train variabilities (e.g. camphasers, variable valve lift systems)
• In-cylinder charge motion and interaction with mixture preparation
• Resulting combustion characteristics
• Naturally aspirated and boosted operating conditions

The paper presents an advanced development process, where a dedicated interaction between

• Gas dynamics and CFD simulation,
• Optical analysis tools (3D-PIV) and
• Engine test bench

is used.

Simulation approaches are typically used during the first concept and following design phase. Due to the complexity of simulation models and the need for a detailed validation, advanced optical analysis tools need to be integrated in the development process. Among others a 3D-PIV test bench is set-up to analyze the flow pattern inside the cylinder especially during the intake phase in all relevant details. The validated model is then used to improve quality of combustion simulation and a higher accuracy of process prediction is realized. The simulation prediction is finally checked by engine test bench investigations.

The methodology is exemplary shown for small displacement engine versions. Finally, a detailed assessment can be realized, which takes into account all relevant development targets.