Advanced automotive engine thermal management Simplified diesel engine model and experimental validation

Diesel engines fulfill diverse demands in urban and rural areas throughout the world. While the advantages of compression ignition engines are superior to other internal combustion engines in torque generation and fuel efficiency, some diesel exhaust emissions pose health and environmental problems. Emission reduction techniques generally diminish one type of tailpipe gas yet often sacrifice engine performance and may even raise other emission levels. For instance, exhaust gas recirculation can reduce NOx emissions. However, the dilution of the combustion charge with hot inert exhaust gas hinders the engine's power characteristics. To solve this problem, an EGR cooler allows the exhaust gases to be cooled prior to mixing with intake air allowing a denser cylinder charge for combustion. The effective application of cooled EGR requires a smart thermal management system. In this paper, a real time empirical and analytical model will be introduced to estimate the diesel engine's overall performance. The simplified model considers the engine's combustion chemistry, as well as the thermal, emissions, and rotational dynamics. Representative numerical and experimental test results are presented and discussed to validate the model. Eventually, an on-board computer controller will use this model to regulate the EGR valve's functionality and the smart thermal system.