Abstract
Keywords:
Spark Ignition Engine, Ignition, Combustion, CFD, Level Set Method
Abstract
A three-stage combustion process is designed to deal with spark ignition, flame propagation and post-flame combustion in SI engines. Both the spark ignition kernel development and the flame propagation are based on the Level-Set method. The spark ignition model accounts all fundamental properties of ignition system, mixtures and flow field. The kernel development is fully coupled with the flow field and a Lagrangian tracking correction is used to correct the kernel size. It is essential to carry out the simulation of whole engine operation procedure to give the initial field and condition accurately for the combustion simulation of realistic SI engines. The combustion models are applied to a vessel with premixed propane air mixture and a visualization gasoline SI engine. By comparing the pressure histories and the flame photos with the simulation results, the combustion models are validated. In addition, the models are used to predict the cylinder pressure and NOx emission at different air-fuel ratio in a port-injection gasoline SI engine.