Numerical analysis of auto-ignition process in a non-homogeneous mixture

Abstract

An auto ignition process of non-homogeneous mixture was fundamentally investigated using a numerical calculation based on the chemical kinetics and stochastic approach. In the present study, the auto-ignition process of n-heptane is calculated using a reduced mechanism developed by Seiser et al. The non-uniform states of turbulent mixing are statistically described using probability density functions and the stochastic method, which was originally developed based on Curl's model. The results show that the starting points of the low temperature oxidation and ignition delay period are hardly affected by the equivalence-ratio variation, however, the combustion duration increases with increasing variance of equivalence ratio. Furthermore, the combustion duration is mainly affected by the non-homogeneity at the ignition and not very much affected by the mixing rate.