rate-controlled constrained-equilibrium modeling of nC₄H₁₀/O₂/diluent mixtures

• Online Access: http://hdl.handle.net/2047/D20315055

The objective of this thesis is to develop and apply the Rate-Controlled Constrained-Equilibrium (RCCE) method to study the combustion of nC4H10/O2/Diluent mixtures. The RCCE is a dimension reduction technique for chemical kinetics based on local maximization of entropy or minimization of a relevant free energy at any time during the non-equilibrium evolution of the system subject to a set of kinetic constraints. The RCCE rate equations can be formulated in terms of constraints or constraint potentials. Direct integration of the rate equations for the constraint potentials were used in this paper, once the values of which are known, the concentration of all species can be calculated. The Hai Wang's USC 2.0 model has been used for studying the detailed kinetic model (DKM), which is a high temperature combustion model suitable for H2, CO and C1-C4 hydrocarbon compounds developed in 2007. The model consists of 111 species and 784 reactions and is constructed based on the GRI model with updated H2-CO and C2-C4 sub-mechanism. Under a wide range of initial conditions, a group of 17 constraints is found to be highly consistent with the detailed kinetic model. Moreover, this group of 17 constraints also has been proved to predict well the ignition delay time from shock tube experiments. Argon was used as diluent when doing the comparison between the calculation result of RCCE, DKM and experimental data.