Radial Combustion Dynamics in Fe2O3/Al Thermite Mixtures: Variability of the Flame Propagation Profiles

Radial combustion in thin circular samples of stoichiometric and over aluminized Fe$_2$O$_3$/Al mixtures is studied. Two confinement materials are tested: stainless steel and PVC. The combustion front profiles are registered by digital video-crono-photography. The radial geometry allows an easy detection of sample heterogeneities, since they cause distortions on the combustion front profiles circularity. The influence of the mixtures Al content and type of confinement on the combustion propagation dynamics is analyzed. In addition, an asymmetry analysis of the combustion front profiles is performed, defining an asymmetry parameter and using ANOVA. Although the type of confinement contributes more than the mixture composition to the variability of the asymmetry parameter, they both have a weak influence. The main source of variability is the intrinsic variations of the samples, which are due to their heterogeneous character.