Master Equation Study and Nonequilibrium Chemical Reactions for H + H2 and He + H2

Rovibrational Energy Transitions and Coupled Chemical Reaction Modeling of H+H2and He+H2in DSMC

“…In comparing with the VHS model, the differences of the total cross sections are discernably shown at the vibrational states v > 5 and translational energy E tr > 1 eV. In this energy region, most of the dissociation of H 2 are occurred by coupling with the rovibrational states of H 2 [7,8], and the state-specific total cross sections can accurately describe the nonequilibrium chemical reactions.…”

“…In Eqs. (7) and (8) to-state transition cross sections, and these cross sections are obtained from the work by Kim et al [7,8]. In this work, the state-to-state cross sections were obtained from the atomistic calculations of QCT method based on the complicated potential energy surfaces [20,21].…”

“…In the state-resolved method of bound-bound transitions, the state-to-state transition probabilities of the atommolecule collisions are determined as 7 However, in the H 2 molecule, the rovibrational states are fully coupled [7,8] and the RVT energy transitions have an important role in describing the thermochemical nonequilibrium of H 2 , and the LB model has a limitation in describing the RVT energy transitions [19]. In the present work, the stateresolved method to describe the RVT energy transitions and coupled chemical reactions for H+H 2 and He+H 2 is constructed without relying on a macroscopic properties and phenomenological models of the DSMC.…”

“…However, these models are insufficient: the chemical reactions are dominantly affected by the thermal nonequilibrium of rotational and vibrational modes induced by the state-to-state kinetics. Also, in the previous master equation studies of H 2 [7,8], it was found that the rotational-vibrational-translational (RVT) energy transitions have an important role in thermochemical nonequilibrium. These phenomena cannot be fully accounted for in these previous DSMC works because the LarsenBorgnakke (LB) model [1] adopted in the previous works has a limitation in describing the RVT energy transitions and it has a phenomenological nature and simulates the energy transitions depend on the macroscopic properties.…”

“…These transition probabilities are defined by dividing the rovibrational state-to-state transition cross sections by the state-specific total cross sections. The state-to-state transition cross sections are taken from the existing work by Kim et al [7]. By using the state-resolved method, the DSMC calculations including the RVT energy transitions and coupled chemical reactions are carried out in various heat bath conditions.…”