Effect of different hydrogen blending ratios on combustion process of gasoline‐fueled rotary engine

Abstract

The pre‐eminent gasoline rotary engine may be criticized for its unsatisfactory fuel consumption rate and unburnt emissions. The clean and renewable hydrogen fuel is a promising alternative for conventional fuels to improve the combustion process and power performance of the rotary engine. In this article, highly advanced numerical simulation was used to obtain some pivotal results such as the distribution of combustion intermediates, the turbulent kinetic energy, the kinetic rate of reactions, and the fuel concentration fields which are difficult to experimentally achieve. An experimentally validated three‐dimensional dynamic simulation model of a rotary engine coupled with chemical kinetics skeletal mechanism was set up to exactly investigate the effects of hydrogen blending on the combustion process, power performance, and pollutant emissions. The results showed that with the increase of hydrogen mixing ratio, the average pressure and the peak pressure increased in the combustion process. Meanwhile, more combustion active intermediates were generated in both the flame development period and flame propagation period. The mass fraction of OH and H radicals has an increase of 36% and 34%, respectively. The fuel combustion rate rose and the turbulent kinetic energy increased which are conducive to improving flame diffusion in the rear part of the chamber and thus facilitate the complete combustion of the fuel. Moreover, the hydrogen blending led to an effective reduction in the CO emission of gasoline‐fueled rotary engine; however, the NO emission slightly increased due to the rise of temperature in cylinder. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019