The Effect of Exhaust Gas Recirculation on Performance and Emissions of a SIEngine Fuelled with Ethanol-gasoline Blends

In this paper, performance and emissions of a four-stroke SI engine operating on ethanol-gasolineblends of E0, E5 and E10 in a rational range of exhaust gas recirculation (EGR) with the aid of a 3DCFD code has been studied. CFD codes do not share high expenses and operational difficulties ofexperimental studies, but they do present acceptable results. The results of simulation were comparedwith the experimental data. There is a good agreement betweethe results. In this study, a novel methodfor decreasing the engine emissions has been investigated for the fuels under study. Calculations werecarried out for EGR ratios between 0 and 20%. The results revealed that using ethanol-gasolineblended fuels marginally increases the power output of the engine. The concentration of CO and HCemissions were measured and found to decrease when ethanol blends were introduced. This was due tothe high oxygen percentage in ethanol. In contrast, the concentration of CO2 and NOx was found toincrease when ethanol is introduced. Increasing EGR level while proved to have a significantdecreasing effect on engine power, but also hada slight emission reducing effect on almost all of theCO and HC levels up to 10% of EGR and a notable plummet in NOx emission levels.