Analysis of coupled-waves structure and propagation characteristics in hydrogen-assisted kerosene-air two-phase rotating detonation wave

In order to investigate the structure and propagation characteristics of hydrogen-assisted kerosene (liquid phase)-air rotating detonation, a modified solver based on OpenFOAM (R) was proposed and utilized to simulate detonation in the mixture of hydrogen, liquid kerosene and air. The obtained results show that evaporation waves exist in the discrete liquid mist detonation, and the coupled-waves structure formed by the evaporation wave (EW) and the incident shock wave (ISW) propagates upstream. By analyzing the overall and instantaneous propagation characteristics, it is found that the propagation speed of the detonation wave increases with the increase of the equivalence ratio at the fuel rich state. Increasing the droplet size will cause the evaporation wave to be further downstream relative to the ISW, resulting in lower evaporating pressure. The effect of EW on ISW is accomplished by the blast wave traveling upstream which is generated by droplet reaction, while EW is influenced by the ISW by modulating the droplet enthalpy and the pressure attenuation following ISW. Part of the droplet reaction energy is held in the gap between the EW and ISW, consequently the gap acts as an energy storage piston, regulating the ISW and EW propagation speeds. The combustion of droplets with smaller sizes imposes more positive feedback on their evaporation, and increasing the total temperature of the pre-mixed gas promotes the interaction between the EW and the ISW, resulting in a more steady propagating overall structure. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.