Two-Temperature Approximation of CO2 Dissociation Kinetics in Non-Thermal Plasma

Two-Temperature Approximation of CO2 Dissociation Kinetics in Non-Thermal Plasma 

If temperatures related to different vibrational modes are different, then transition to quasi continuum takes place along the mode characterized by the highest temperature. Let us specify the asymmetric vibrational temperature as a higher one (Lva fys). Transition to the vibrational quasi continuum then takes place during excitation along the asymmetric mode, and the vibrational quantum number for the symmetric modes can be chosen as fixed on its average value Til  

The vibrational energy on the asymmetric mode necessary for transition to quasicontinuum can be determined from (5-19) taking into account (5-23)  

Numerically, E (15-20) x Ua at Tvs = 1000 K, which means that the transition to quasi continuum actually takes place at very high levels of excitation of the asymmetric vibrational mode, close to the dissociation energy (see Fig. 5-14). Thus, most of the vibrational distribution function relevant to CO2 dissociation in this case, in contrast to the one-temperature approach, is not continuous but discrete. The discrete distribution function /(Va, Vs) over vibrational energies (5-16) can be presented analytically according to Licalter (1975a,b, 1976) in the Treanor form  

Most of the symbols in (5-26) are the same as those in expression (5-22) for the dissociation rate coefficient in a one-temperature approximation. Additionally, d = Aty/XasUl is a vibrational quantum number corresponding to the transition to quasi continuum along the asymmetric mode (5-24) f E) is the vibrational energy-dependent ratio of rate coefficients of VT and W relaxation (see Fig. 5-12) y = is the logarithmic sensitivity of the VTAA relaxation ratio to vibrational energy accumulated on the asymmetric mode (see Fig. 5-12) and Xm is the effective CO2 oscillation anharmonicity in quasi continuum (for 

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