Combustion characteristics of a spark ignition engine fueled by high proportion ethanol-gasoline blends: A simulation approach

This research aims to find the effects of ethanol-gasoline blends on the combustion process of an automobile engine by a simulation approach. A comprehensive simulation model was developed based on dedicated AVL Boost and to be validated by experiment data. The engine model was controlled to operate with different ethanol-gasoline blends. In addition, the use of HHO as an additional supplement in the intake system was considered as a solution for the engine's technical performance and combustion process. The simulation process was carried out with various ethanol blending ratios ranging from E100 to E50, as well as conventional gasoline. HHO was introduced into the intake manifold as an additive at a ratio of 0.1% by volume the intake air, with the aim of improving the combustion quality in engines using ethanol-gasoline blends. Combustion characteristics such as in-cylinder pressure, temperature, heat release rate (RoHR), and Mass Fraction Burned (MFB) were analyzed and evaluated across different fuel scenarios. The simulation results showed that for high ethanol blends (from E70 to E100), the combustion process tended to be slower, as indicated by a decrease in peak pressure, peak temperature, and RoHR. In contrast, the E50 blend yielded better performance, with improvements in all these indicators. When HHO was added to the intake as an additive, it enhanced the combustion process, reflected in increased pressure, temperature, and RoHR. The impact of HHO became more pronounced with higher ethanol content in the fuel, especially in the E100 blend.