Study on the combustion characteristics of furan- and nitromethane-added hydrocarbon fuels

Abstract

In this study, the combustion characteristics of furan and nitromethane-added fuels were studied to clarify the thermal efficiency improvement mechanism in engine experiments. The laminar burning velocity was measured using a constant volume chamber. The laminar burning velocity of the furan was found to be high, but the effect of the furan addition on the laminar burning velocity was small. Alternatively, the addition of furan to S5H was found to increase the lean flammability limit, which can be related to the thermal efficiency improvement in engine experiments. In addition, extinction characteristics were evaluated for diffusion flames using a counterflow burner. Consequently, it was found that furan exhibited large resistance for flame extinction. The extinction characteristics of furan can result in an increase in the lean flammability limit of furan-containing fuel, which can improve the thermal efficiency of the engine following the addition of furan. However, nitromethane has smaller resistance for flame extinction than isooctane in terms of diffusion flames, which is considered to be a consequence of the decreased laminar burning velocity near the stoichiometric mixture of nitromethane compared with the fuel-lean scenario.