Three Dimensional Modeling of Combustion Process and Emission Formation in a Spark Ignition Engine

World Applied Sciences Journal 18 (7), 2012. — pp. 890-895.Abstract: This paper is presented to numerically study the combustion process and pollutant formation in the Samand XU7 JP Spark Ignition (SI) engine at various engine speeds. The computations are carried out using three-dimensional model for flows, combustion and emissions in SI engines. Four engine speeds have been studied: 1500, 2000, 3000 and 4000 rev/min. The obtained results indicate that spark timing should be advanced by increasing engine speed and ignition delay and combustion duration are increased respectively. Also by increasing engine speed from 1500 rev/min to 4000 rev/min CO quantity increases about 40 percent and NOx quantity increases about 2.5 times. The obtained results are compared to the experimental data measured at Iran Khodro Powertrain Company (IP-CO) for in-cylinder pressure and emissions at various engine speeds. There is a good agreement among the results. The simulation results show that the CFD combustion simulation tool, works quite correctly for the predicting combustion process and emission formation in Samand SI engine.