Sum over Histories Representation for Kinetic Sensitivity Analysis: How Chemical Pathways Change When Reaction Rate Coefficients Are Varied.
The sensitivity of kinetic observables is analyzed using a newly developed sum over histories representation of chemical kinetics. In the sum over histories representation, the concentrations of the chemical species are decomposed into the sum of probabilities for chemical pathways that follow molecules from reactants to products or intermediates. Unlike static flux methods for reaction path analysis, the sum over histories approach includes the explicit time dependence of the pathway probabilities. Using the sum over histories representation, the sensitivity of an observable with respect to a kinetic parameter such as a rate coefficient is then analyzed in terms of how that parameter affects the chemical pathway probabilities. The method is illustrated for species concentration target functions in H2 combustion where the rate coefficients are allowed to vary over their associated uncertainty ranges. It is found that large sensitivities are often associated with rate limiting steps along important chemical pathways or by reactions that control the branching of reactive flux.
Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States.|Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
Shirong
S
Bai
Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
Michael J
MJ
Davis
Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States.
Rex T
RT
Skodje