Non-equilibrium dissociation rates in expanding flows

Vibrational and Chemical Kinetics in Non-Equilibrium Gas Flows

“…The following conditions in the throat are considered: for O 2 /O mixture, T * = 4000 K, p * = 1 atm; for N 2 /N mixture, T * = 7000 K, p * = 1 atm. Two kinds of multi-temperature distributions are applied: the Boltzmann distribution for harmonic oscillators and a complex distribution for anharmonic oscillators studied in Kustova et al (2003). One can see a quite strong influence of the kinetic model on the averaged dissociation rate coefficients, all quasi-stationary models give the values of k mol diss rather far from those obtained in the rigorous state-to-state approximation, the same effect is obtained for k at diss .…”

“…On the basis of obtained distributions, global reaction rates (92) were calculated in relaxation zone behind the shock wave and in nozzle expansion Kustova et al (2003) diss as a function of x. Curves 1, 2, 3 are, respectively, for the state-to-state, two-temperature, and one-temperature approaches.…”

“…More rigorous models of non-equilibrium kinetics in a flow take into account the non-Boltzmann quasi-stationary distributions or the state-to-state vibrational and chemical kinetics Kustova et al (1999); Nagnibeda & Kustova (2009). The influence of state-to-state and multi-temperature distributions on reaction rates in particular flows are studied in ; Kustova et al (2003). Recently the comparison of kinetic models for transport properties in reacting gas flows has been discussed in Kustova & Nagnibeda (2011).…”

A Reduced Order Maximum Entropy Model for Chemical and Thermal Non-equilibrium in High Temperature CO2Gas

“…An exact population distribution of particles corresponding to different quantum energy states can be obtained by accounting for all state-tostate collisions between atoms, molecules, and electrons, and the emission and absorption of photons. The availability of first-principles based ab-initio rate data [12,13,14,15,16,17], characterizing microscopic interactions of colliding particles, for different systems like N 2 -N 2 , CO -O, and CO 2 -M, provides an unprecedented level of physical realism in describing the non-equilibrium state of a gas mixture. But in reality, computing the population of each individual energy state for even the simplest flow problem would be unfeasible, owing to the large number of excited states and excitation pathways in a gas.…”