Conditional and Opposed Reaction Path Diagrams for the Analysis of Fluid-Chemistry Interactions

Introduction. Gardiner [1] observed that “progress in achieving understanding through combustion modeling is now limited by the ability to recognize the implications of what has been computed and to draw conclusions about the underlying reaction mechanisms.” This paper considers how to use reaction path diagrams to better understand reacting flow simulations. We are not aware of any comprehensive treatment of these diagrams from this perspective. In exploring the subject we discover some new information about the chemistry of . Most reaction path diagrams are of a kind called “schematic” [2] because they depict all the theoretically possible reactant-product dependencies in the elementary steps of a chemical mechanism. The diagrams of interest in this paper have path thicknesses that convey quantitative information about the reactions occurring in a fluid-flow simulation. The purpose of these diagrams is to determine which paths may be important in flames. Identifying them is not a purely chemical question, because the answer depends on which species the fluid can bring together to react in quantity.