Effects Of Fuel Characteristics On Spark Ignition Engine Performance

This paper studies the effect of fuel characteristics on spark ignition engine performance. According to the operation mechanism of the engine, the combustion model and the related sub-model are developed. These sub-models include the mass fraction burned model, the instantaneous heat transfer model and the equilibrium combustion production model etc. Basing on the first-law of thermodynamics and the turbulent flame front speed model, the variations of thermomechanical availability, chemical availability, availability destruction due to combustion and availability destruction due to heat transfer are studied through the method of the availability analysis. The study also analyzes the effects of working conditions and boundary conditions on the availability destruction due to irreversibility during combustion process, especially the different fuel compositions. This paper mainly considers the two kinds of situations: surrogate fuel compositions for gasoline and hydrogen blending.The developed model is applied to study the effects of the different engine operation parameters (compression ration, fuel mixtures of hydrogen and gasoline, air-fuel ratio, ignition timing and combustion duration) on the combustion performance. By this way, the effect of operation parameters on achieving the low irreversibility of engine can be confirmed. Through the research, the potential of reducing the irreversibility and improving the efficiency of engine can be deeply understood. In practical applications, give full use to the advantages of alternative fuels, so that spark engine achieves the higher thermal efficiency, lower irreversibility and lower emissions. All of these can provide references for improving the engine performance.