Simulation of ignition and combustion wave propagation in enclosed C 2H 6/O 2/N 2 mixtures

Abstract

The dynamics of one-dimensional C2H6/Air combustion waves originating from hot-spot ignition was studied numerically by solving the corresponding conservation equations for mass, species, energy and momentum. The model included a detailed reaction mechanism and a multispecies transport model. The numerical solution was based on the method of lines and on a dynamic adaptive grid technique. Due to the stiffness of the resulting differential equations, a BDF-code was used to integrate the system. In this work, hot-spot ignition was studied for a reaction system under high pressure and high temperature conditions. The results show that hot-spot ignition can cause different combustion phenomena depending on the shape of the temperature nonuniformity. A supersonic combustion wave was observed when the velocity of the temperature-gradient based autoignition wave was much higher than the velocity of pressure waves. Detonation wave initiation was the result when an interaction between ignition process and pressure wave was possible. Ordinary flame propagation occurred, when the mixture outside the hot-spot was far away from autoignition.