A dependable combustion model must be built up from reliable chemical parameters. Recent progress in theoretical methodologies and computational capabilities make these highly predictive thermochemical kinetics computations possible. We are building PACChem, a large-scale, automated, combustion chemistry modeling software package. It accurately predicts the thermochemical properties and temperature and pressure dependence of the thousands of gas phase reactions in a combustion mechanism by providing a unified interface for electronic structure and transition state theories, mechanism generation and reduction, classical trajectory simulations, the master equation, and uncertainty quantification methods. We are using PACChem to provide thermochemical parameters, within thermochemical accuracy, for a set of 300 core combustion species through careful treatment of the electronic and nuclear degrees of freedom. PACChem facilitates our analysis of a series of computational protocols which involve various electronic structure methods, bond additivity and connectivity-based hierarchy corrections, and high-level treatments of anharmonicities and nonlocal motions.
University
University of Georgia