Flame front inclination instability in the porous media combustion with inhomogeneous preheating temperature distribution

Abstract The present work examines effects of the initial inhomogeneous preheating temperature distribution on the flame front inclination instability in porous media combustion experimentally and numerically. The inclination evolution is observed in a vertical burner with a packed bed of alumina pellets experimentally. Correspondingly, a 2D two-temperature mathematical model is developed in simulation. To understand the inclination mechanism, the whole process of the inclination evolution is divided into three stages according to the inclination angle growth rate. Different performances of the inclination are obtained and discussed for different factors, such as the initial preheating temperature perturbation, the gas inlet velocity and the equivalence ratio. Conclusively, a larger initial preheating temperature perturbation, a greater gas inlet velocity and a smaller equivalence ratio can lead to a more serious inclination. The results are helpful to guide the design and operation of the porous media burner.