F2008-06-015
The Future Power Density of HSDI Diesel Engines with Lowest Engine Out Emissions - A Key Element for Upcoming CO2 Demands
Regulated emissions, CO2-values, comfort, good driveability, high reliability and costs, this is the main frame for all future powertrain developments. In this frame, the diesel powertrain, not only for passenger cars, but also for commercial vehicle applications, faces some challenges in order to fulfil the future European and current US emission legislations while keeping the fuel consumption benefit, good driveability and an acceptable cost frame. One widely discussed approach for fuel consumption improvement within passenger car applications, besides further engine and vehicle measures, is to incorporate the downsizing effect; certain publications have already discussed strategies for diesel engines with reduced capacity and the correlating impact on fuel consumption, emissions and the necessary hardware re-configuration. Still under discussion is the question, to what extend downsizing for passenger car diesel engines is possible and what is the margin for further performance improvement with downsizing. In this context, this publication deals with the further potential of increasing the specific power for HSDI diesel engines. This includes in detail the topics of necessary measures to achieve higher specific power output while keeping the engine-out emissions favourable for legal demands and fuel economy on superior level. In addition to that, by means of cycle simulations, the achievable degree of downsizing, dependent on the specific power, will be analysed and consequences for engine-out emissions and fuel consumption are formulated. The shown results are based on theoretical pre-studies, detailed CFD combustion analysis, representative single cylinder measurements as well as test cycle simulations.
Session: Engine Concepts