Development of a Charge Motion Controlled Combustion System for DI SI-Engines and its Vehicle Application for EU-4 Emission Regulations

The development of new passenger car powertrains with gasoline direct injection engines is facing new requirements which result from the need of different operational modes with stratified and homogeneous air fuel mixture. Moreover, the exhaust aftertreatment system causes a discontinuous operation with lean burn adsorption periods followed by short rich spikes for catalyst regeneration.

Recent work on combustion system development has shown, that gasoline direct injection can create significant fuel economy benefits. Charge motion controlled combustion systems have proven to be of advantage in terms of low raw emissions compared to wall guided concepts. Based on an initial single-cylinder development phase a multi-cylinder engine was realized with excellent fuel economy, low raw emissions and operational robustness. Finally, the new engine's potential has been demonstrated in a mid-class vehicle.

The paper reports on the total development process starting from single-cylinder testing through to engine-to-vehicle calibration. The discussion also includes the efficient use of development tools. The evaluation of fuel economy and emission potential is derived from different development programs which are based on applications of the charge motion controlled direct injection technology.