Thermodynamic and Transport Properties of Two-Temperature Nitrogen-Oxygen Plasma

Abstract

Thermodynamic and transport properties are computed for a 17 species model of nitrogen-oxygen plasma under different degrees of thermal non-equilibrium, pressures and volume ratios of component gases. In the computation electron temperatures range from 300 to 45,000 K, mole fractions range from 0.8 to 0.2, pressures range from 0.1 atmosphere to 5 atmospheres, and thermal nonequilibrium parameters (T e /T h ) range from 1 to 20. It is assumed that all the electrons follow a temperature T e and the rest of the species in the plasma follow a temperature T h . Compositions are calculated using the two temperature Saha equation derived by van de Sanden et al. Updated energy level data from National Institute of Standards and Technology (NIST) and recently compiled collision integrals by Capitelli et al., have been used to obtain thermodynamic and transport properties. In the local thermodynamic equilibrium (LTE) regime, the results are compared with published data and an overall good agreement is observed.

Basic knowledge on radiative and transport properties to begin in thermal plasmas modelling

“…For the 2T transport properties, several works were published [117][118][119][120][121][122] and used two approached: with coupling or without coupling between the electrons and the heavy particles. Ghorui 116 and Colombo 117 compared the two theories and concluded that Devoto's approach (without coupling) was adequate to determine the electrical conductivity, the viscosity and the thermal conductivity of a nonequilibrium plasma even if the diffusion coefficients used in the expressions were obtained by the Ramshaw's approach. 123 Today, most of the works published seem to agree on the expressions to be used to calculate the viscosity, the electrical conductivity, the internal and translational thermal conductivities.…”

Thermodynamic and transport properties of two-temperature SF6 plasmas

“…Here following the definition of Ghorui et al, 21 the total thermal conductivities for electrons and heavy particles as k e and k h , respectively, can be expressed as follows…”

“…[5][6][7][8][9][10][11][12][13] For two-temperature plasmas, different authors have recently displayed calculations of the composition, thermodynamic, and transport properties for some pure gases and some gas mixtures. [14][15][16][17][18][19][20][21][22][23][24][25] As for pure SF 6 gas, several papers have so far dealt with the particle compositions in twotemperature state. [26][27][28][29] The determination of twotemperature plasma composition as a function of pressure, electron temperature, and heavy particles temperature is closely related to the mass action law of different reactions (Saha and Guldberg-Waage laws), the Dalton's law, species conservation law together with the electrical quasineutrality condition.…”

In Memoriam

“…Emil Pfender devoted a significant part of his research efforts to the study of the thermodynamic and transport properties of plasmas under a wide range of conditions (Ref [13][14][15][16][17][18][19][20]. He showed that multicomponent transport determines the actual outcome of many thermal plasma processing techniques.…”