  Regimes of chemical reaction wave propagating in reactive gaseous mixtures,
whose chemistry is governed by chain-branching kinetics, are studied depending
on the characteristics of a transient thermal energy deposition localized in a
finite volume of reactive gas. Different regimes of the reaction wave
propagation are initiated depending on the amount of deposited thermal energy,
power of the source and the size of the hot spot. The main parameters which
define regimes of the combustion waves facilitated by the transient deposition
of thermal energy are: acoustic timescale, duration of the energy deposition,
ignition time scale and size of the hot spot. The interplay between these
parameters specifies the role of gasdynamical processes, the formation and
steepness of the temperature gradient and speed of the spontaneous wave. The
obtained results show how ignition of one or another regime of combustion wave
depends on the value of energy, rate of the energy deposition and size of the
hot spot, which is important for the practical use and for risk assessment.

Chemical Physics;Fluid Dynamics