Automotive Engineering Commons^™

Effects Of Variable Valve Actuation On Exhaust Enthalpy And Engine Out Emissions, Zakarie Parker

Dissertations, Master's Theses and Master's Reports

Vehicle emissions standards are becoming increasingly more strict as time progresses. Once all of the emissions devices are in their operational stage, these standards can be met with reasonable effort in powertrain design and calibration. However, the core of this system, the three-way catalyst, is non-operational until it has reached 200-350⁰C. Because of this, cold-start catalyst heating is extremely important in new vehicles. The objective of this project was to improve catalyst heating without increasing engine-out emissions. It was decided that the sensible heat portion of the exhaust enthalpy would be the best metric to judge differences between the different …