A Multi-Scale Numerical Model for Investigation of Flame Dynamics in a Thermal Flow Reversal Reactor

Abstract

In this paper, the flame dynamics in a thermal flow reversal reactor are studied using a multi-scale model. The challenges of the multi-scale models lie in the data exchanges between different scale models and the capture of the flame movement of the filtered combustion by the pore-scale model. Through the multi-scale method, the computational region of the porous media is divided into the inlet preheating zone, reaction zone, and outlet exhaust zone. The three models corresponding to the three zones are calculated by volume average method, pore-scale method, and volume average method respectively. Temperature distribution is used as data for real-time exchange. The results show that the multi-scale model can save computation time when compared with the pore-scale model. Compared with the volumetric average model, the multi-scale model can capture the flame front and predict the flame propagation more accurately. The flame propagation velocity increases and the flame thickness decreases with the increase of inlet flow rates and mixture concentration. In addition, the peak value of the initial temperature field and the width of the high-temperature zone also affect the flame propagation velocity and flame thickness.

Keywords

• filtration combustion
• porous medium
• multi-scale model
• numerical simulation
• flame propagation