A comparative study of performance and emissions of a SI engine runningon alternative fuels

The strict environmental laws, the cost of oil and its limited resources, have made the engine manufacturers tothink of other energy resources rather than oil and its products. In this study the effect of exhaust gasrecirculation (EGR) on performance and emission characteristics of a SI engine fueled separately with gasoline,hydrogen, ethanol, methane, methanol and propane have been compared and discussed. In order to do that theengine has been simulated with a three dimensional computational fluid dynamics (CFD) code. The validationresults prove that the code has the ability to evaluate performance and emission characteristics of this engine.The results show that in the identical condition as the EGR rate raised, although emission levels plummeted, butdue to substantial fall in flame speed, a significant decrease in indicated mean effective pressure (IMEP) levelsoccurs. Hydrogen even though, because of its high heating value shows the least decrease in comparison with theother fuels.

کلیدواژه ها:

Alternative Fuels ، SI Engine ، Exhaust Gas Recirculation