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

TL;DR

This paper investigates how different regimes of combustion wave propagation are initiated in reactive gases due to transient thermal energy deposition, emphasizing the roles of energy amount, source power, and hot spot size.

Contribution

It provides a detailed analysis of the parameters influencing combustion regimes triggered by localized transient energy deposition in reactive gases.

Findings

Regimes depend on energy amount, deposition rate, and hot spot size.

Gasdynamical processes significantly influence ignition regimes.

Results aid in practical ignition control and risk assessment.

Abstract

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.