Gasoline DI Engines: The Complete System Approach By Interaction of Advanced Development Tools

Gasoline direct injection is one of the main issues of actual worldwide SI engine development activities. It requires a comprehensive system approach from the basic considerations on optimum combustion system configuration up to vehicle performance and driveability.

The general characteristics of currently favored combustion system configurations are discussed in this paper regarding both engine operation and design aspects. The engine performance, especially power output and emission potential of AVL's DGI engine concept is presented including the interaction of advanced tools like optical diagnostics and 3D-CFD simulation in the combustion system development process. The application of methods like tomographic combustion analysis for investigations in the multicylinder engine within further stages of development is demonstrated.

The system layout and operational strategies for fuel economy in conjunction with exhaust gas aftertreatment requirements are discussed.

For the optimization of the complex transient functions as e. g. switching between stratified and homogeneous operation and catalyst purging, a new evaluation tool providing objective driveability assessment is applied.