Combustion properties of a simple and efficient four-step model

Abstract

Modeling of the chemistry and thermodynamics is crucial in numerical simulations that attempt to accurately simulate reactive flows such as flame acceleration and detonation phenomena. The current study explores how a four-species, four-step combustion mechanism performs to predict ignition processes in various premixed hydrocarbon fuel mixtures when compared to detailed chemical kinetic mechanisms. A key objective of this research is to determine how well this model, which has been modified to include only three species transport equations, performs at predicting fundamental combustion properties that are important for flame acceleration and detonation applications. On comparison with full chemistry mechanisms, the four-step model demonstrates an ability to predict the ignition time, reaction stiffness, thermodynamic state, and detonation stability-parameter to a high level of accuracy, for ignition processes over a wide range of initial temperatures and densities. With the ignition structures and key detonation stability parameters correctly predicted, we conclude that the four-step model is an effective and economic tool for studying complex explosion phenomena in situations where pre-combustion temperature and density are constantly changing, such as deflagration-to-detonation transition by flame acceleration or shock–flame interaction.