Effect of Thermal Resistance on the Random Combustion of Micro-Organic Dust Particles

Abstract

A new mathematical model is presented to investigate the random combustion of a combustible mixture of micro-organic dust particles and air. For this purpose, a model is developed assuming a flame structure composed of three zones: a broad preheat zone, a reaction zone, and a postflame zone. The random modeling of the combustion process is brought about by adding a source term in the energy equation indicating the random states of particle volatilization in the preheat zone. The effect of thermal resistance on the combustion characteristics, such as flame temperature and burning velocity, is studied using a nonzero Biot number in the model. Moreover, it is observed that particle size considerably impacts the flame propagation through organic dust particles. As a result, it is concluded that the increase in Biot number leads to a decrease in the burning velocity as well as flame temperature. The novelty of this research is the improved understanding of the random distribution of the combustion phenomenon, which leads to more realistic and reasonable predictions of the combustion physics compared to the previously published analytical and experimental results.