Experimental and numerical studies on inclined flame evolution in packing bed

Inclined flame evolution in cylindrical porous media combustors were investigated experimentally and numerically using a two-temperature and two-dimensional model. A detailed process of the flame inclination evolution in the burner is recorded simultaneously by two cameras with a shooting angle of 90°. Downstream propagating flames in methane/air mixture are observed in quartz tubes with inner diameter 61 mm for mixture velocity of ug = 0.42 m/s, equivalence ratios of 0.45 and 0.48. The experiments show that the initially symmetric flat flame transformed to a slightly asymmetric structure at the startup moment. Then a smaller inclination angle occurs on the upstream side and gradually increases and leads to the appearance of a crack shape structure, which eventually splits into two high temperature zones. In the simulations, the flame instability is numerically examined by imposing an initially inclined angle of the hot solid zone in the burner. The model captures the main features of the process observed in the experiment and characteristic inclination reported by the previous study. In addition, results show that the hydrodynamics has significant influence on the inclination evolution.