Implementation of a Chemical Kinetics Model for Hypersonic Flows in Air for High-Performance CFD

Direct numerical simulation of a hypersonic transitional boundary layer at suborbital enthalpies

“…Additionally, F ij is the chaperon efficiency of species i participating as a third body in reaction j, and k f ,j and k b,j are, respectively, the forward and backward rate constants of the jth step, which are evaluated here in terms of the equilibrium temperature T. Details of the chemical mechanism, including the values of F ij and k f ,j for the reactions (R1)-(R5) used in this study, can be found in Park (1989b). More complex dissociation mechanisms that account for vibrationally excited states exist in the recent literature for operating conditions warranting the consideration of thermodynamic non-equilibrium, as this topic represents an active area of research in hypersonics (Chaudhry et al 2020;Finch et al 2020;Streicher et al 2020).…”

Consistent kinetic-continuum dissociation model. II. Continuum formulation and verification

“…The resulting functional form is similar to that proposed by Morrone and Treanor. Both the full nonequilibrium model and various simplified versions can be easily incorporated into state-of-the-art, multi-temperature CFD codes, as a replacement for current empirical models 36 .…”

“…Recently, Chaudhry and Candler 9 have proposed modifications to the parameter U based on ab-intio QCT and DMS results, that are consistent with the analytically derived model presented in this article. This Modified Morrone and Treanor (MMT) model (along with a version of the full nonequilibrium model listed in the Appendix) has been implemented in the US3D CFD code 36 . It is important to note that such model simplification often introduces a small number of free parameters, that can be "tuned" to obtain very close agreement with overall trends from DMS; potentially obtaining closer agreement than the analytically derived model presented in this article.…”

“…billion-element) CFD simulations. Furthermore, models with simplified functional forms are more easily combined with additional (and necessary) physics models, such as electronic energy effects and recombination chemistry 36 .…”

Consistent Kinetic-Continuum Recombination Model for High Temperature Reacting Flows

“…Other recent efforts of developing a continuum nonequilibrium dissociation model based on recent ab initio data can be found in Refs. [31][32][33][34] . In this work, we extend the modeling efforts to include recombination reactions.…”