Measurements and Prediction of the GUL Engine Emissions by the Two Zone Combustion Model

Report, 1997

The aim of this study was to investigate the trend of the engine emissions according to the Gul & Co - Motor development using cycloid crank-connecting rod instead of the conventional crankshaft. Information from the tests of the Husqvarna Engine Research and constructive information from an Italian engine have been used as the reference performance of the conventional engine. Furthermore, the investigation of the emissions performance of a Gul size engine with conventional crankshaft would be helpful to complete the information on trend of the emissions prediction for the Gul engine. In order to come closer to the real emissions prediction, a two zone combustion model has been developed. Since the two zone model considers unburned and burned gases, the trend of the cylinder gas temperature for burned zone is different from that of the mean gas temperature, which reaches its maximum later than the burned zone. Hence, NOx and CO emissions, which are strongly affected by the temperature, would be more realistic if the emissions formation is calculated according to the thermodynamic properties from the burned zone. This model gives information on unburned and burned gas temperature, NO formation rate, equilibrium mole fraction for the NO at local conditions, average mole fraction at the exhaust etc.