Mechanisms of Ignition by Transient Energy Deposition: Regimes of Combustion Waves Propagation

摘要

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