A Multiple Factor Simulation and Emulation Approach to Investigate Advanced Air Handling Systems for Future Diesel Engines

To realize the required reductions in vehicle CO₂ emissions pursued both voluntarily by the ACEA and possible legislatively by the EC, there is a move to increase the specific power output and thus efficiency of the automotive diesel engine. To this end there is a move towards engine downsizing and the adoption of significantly higher boost levels from air handling systems fitted to the engine. This task is complex and can often result in multiple configurations and iterations of prototype air handling hardware before performance criteria are met.

The work detailed in this paper describes the modeling of high boost engine configurations using cycle simulation and a black box engine approach, the interactions between boost pressures; compression ratio and valve timing and duration have been investigated and will be described. Response surface models for engine performance have been developed such that rapid optimization of the engine air charge handling systems can be performed.

Optimizing the operating conditions for maximum torque and improved fuel consumption will be discussed, particularly with regard to drive cycle performance. Finally the development of an advanced combustion air handling unit (CAHU) and high dynamic exhaust pressure control system that is capable of emulating novel boosting on engine at a conceptual stage will be described. The paper will detail the design and specification of the CAHU hardware. The paper also describes ongoing work to develop real time models of air handling components to integrate with the CAHU system such that future technology combinations of supercharging, e-boosting and sequential turbo charging configurations can be rapidly evaluated specifically in terms of engine transient performance.