RATE-BASED CONSTRUCTION OF KINETIC-MODELS FOR COMPLEX-SYSTEMS

A general-purpose rate-based algorithm for the construction of chemica l kinetic models for systems with hundreds or thousands of reacting sp ecies is presented. The algorithm comprehensively works out the detail s of the chemistry implied by given reaction rate estimation rules, id entifies the species and reactions that are numerically significant, a nd solves the resulting system of differential equations to compute th e concentrations of the significant species as a function of time. A k ey innovation is a definition and numerical test for the ''completenes s'' of the kinetic scheme. This approach obviates the need to arbitrar ily neglect certain species and reactions in order to keep reaction sc hemes small enough to be manageable and allows chemical kinetic modele rs to focus on the chemistry rather than on the computational details. Examples of hydrocarbon pyrolysis and combustion applications are pre sented, where the computer evaluates the importance of nearly 100 000 reactions in the process of identifying the few hundred species that a re kinetically significant. The new algorithm, given reliable rate est imation rules, provides a framework for systematically constructing ki netic schemes including all of the numerically significant species, ev en for systems involving so many reactions that they could not be hand led manually.