Thermal explosion in multiple phase media

Thermal explosion (or self-ignition) is one of the mainly interesting and dangerous phenomena in the combustion. Homogeneous combustible gas mixtures with highly exothermic reaction reveal only two main types of the behaviour: explosive and slow. Transient regime between these main types of behaviour is traditionally called the thermal explosion limit. Addition of another phase (solid or liquid) into combustible gas mixture can lead to essential changes in the dynamical situation. This paper deals with an interesting phenomenon of thermal explosion in two-phase media, so-called thermal explosion with delay. Existence and type of temperature delay before the self-ignition depends on mass and thermal properties of the second phase. The analysis is based on qualitative theory of singular perturbed systems and duck techniques.