Numerical study of governing parameters determining local pore-scale flame dynamics in upstream propagating filtration combustion wave

In previous experiments, two characteristic regimes of upstream flame propagation were observed in model porous media. At the pore scale, the flame can exhibit oscillations similar to those of a flame with repetitive extinction and ignition (FREI-like oscillations) or demonstrate stepwise propagation. The conditions determining the emergence of one propagation regime or the other remained unknown. This work presents a parametric study investigating the influence of parameters on flame behaviour at the pore scale. A reduced 1D model and a detailed 2D model are used for numerical simulation. The results establish that the flame propagation regime is governed primarily by the inlet flow velocity and the maximum pore channel width. Thermophysical properties and pore arrangement have negligible impact on the emergence of oscillations. Despite its quantitative evaluation limitations, the 1D model successfully reproduces the overall flame behaviour at the pore scale and the regime diagram in good agreement with 2D simulations. Thus, the utility of the reduced 1D model for screening governing parameters in pore-scale combustion dynamics is demonstrated.