Magnesium-particle ignition (distributed model)

The Cauchy problem is formulated in its asymptotic variant (transient pointwise model) reduced to a system of three autonomous differential equations, and the existence of its solution is studied on the basis of a distributed model for the heat dynamics of a magnesium particle taking into account a heterogeneous chemical reaction of low-temperature oxidation. Direct computations within the framework of the distributed model show that the temperature gradient along the particle radius is small, and this makes it possible to use the pointwise and transient pointwise models for heat dynamics computations (for particles with radius $\le$ 600 $\mu$m). The ignition delay can differ by 8%. The possibility of extinction of a small heated magnesium particle under the action of high-speed gas flow is shown.