Combustion Kinetic Modeling

Abstract

AbstractCombustion is a complex phenomenon characterized by the interaction and competition of various physical and chemical processes. The correct description of chemical changes requires the application of reaction mechanisms that consist of several hundreds or thousands of elementary reactions. This creates an opportunity for kinetic modeling to play important role in understanding the combustion phenomenon. This chapter provides an overview of combustion modeling, the main aim being to present a comprehensive knowledge base for combustion kinetic modeling. The coupling of fluid dynamics and chemical kinetics using commercial software such as CHEMKIN and FLUENT is also discussed. Moreover, an exemplary approach for reducing complex chemical reaction mechanisms is illustrated with reference to an H2+ O2mixture in an adiabatic system. This approach involves the identification of redundant species via rate sensitivity analysis, and of redundant reactions, by principal component analysis of the rate sensitivity matrix. An eigenvalue–eigenvector analysis is used to extract meaningful kinetic information from linear sensitivity coefficients computed for all species of chemical mechanism at several time points. The main advantage of this method lies in its ability to reveal those parts of the mechanism, which consist of strongly interacting reactions, and to indicate their importance within the mechanism. By using the above procedures, reduced reaction mechanisms could be developed at different chosen conditions and employed in CFD codes in place of detailed mechanisms, giving due consideration to flow fields.