Developments in the Use of Multi-Purpose Numerical Simulation Tools to Optimize Combustion Control Parameters for the 2nd Generation of Lean Burn Stratified GDI Engines

The first part of the paper gives an overview of the current results obtained with the first-generation of GDI-powered vehicles launched on the European market. In view of the rather limited success in fuel consumption gain the second-generation of very lean stratified layouts has begun, but this process requires the development and application of new high-level analysis tools. A possible high performance approach is the multi-purpose use of 3-D numerical simulation both in the development and the engine control strategy calibration phases. The development of a small 1.6 liter lean stratified engine project was chosen to demonstrate the dual application capability of the NCF-3D simulation tool.

The paper continues with a description of the engine application frame, the basic features of the NCF-3D simulation tool and the latest enhancements made to combustion and fuel composition models within the software frame. Hereafter is given a description of the particular computation cluster layout necessary for the use of the numerical simulation tool in the engine control strategy calibration phase. Two significant application examples are given, both related to the 1.6 liter engine development. The first relates to the research and development phase the other to the calibration phase.

The paper concludes with a discussion of the potential of the Computational Cluster Optimization approach to offer a solution which can help to limit the very important work to fine-tune the second-generation of GDI-engines.