Finite Rate Calculations of Magnesium Combustion in Steam Atmospheres

摘要

Towards new-concept magnesium-based hydroreactive metal fuel propulsion,finite rate calculations of magnesium combustion in steam atmospheres based on chemical reaction dynamics is to be investigated,and its underlying thermoacoustic oscillations is to be demonstrated.Especially in this study,considering the influence of water dissociation under high temperature,a one-dimensional numerical simulation of Mg/H2O premixed gas was conducted using the SPIN application of the commercial Chemkin package as an equation solver.The results show that a higher initial temperature of Mg/H2O mixture will lead to a higher equilibrium temperature,and water dissociation will cause temperature decrease after equilibrium point.While the effect of water dissociation on temperature profiles was weakened under high pressure,on the contrary,under a relative low pressure,the effect of water dissociation on the reaction process was found to be significant,even under a lower initial temperature.Considering the unsteady heat release fluctuation due to water dissociation coupled with the sound fluctuations,predictions are also obtained to explain the possibility of thermoacoustic oscillations.