Composition d'équilibre des plasmas de H2, O2 et N2 hors équilibre thermique

Abstract

We study the evolution of the chemical species in off-thermal equilibrium H2, O2, and N2 plasmas, using both methods of maximisation of entropy and minimisation of Gibbs free energy. These gases are simple and used in electric arc cutting techniques in oil, air, or compressed air and in the arc lamination cutting technique. The study of the plasmas from these gases is an important step in understanding the complex physical processes in the CxHyOzNt type of plasmas. Our numerical calculations cover cases from 5000 to 30 000 K at pressure from 0.1-1 MPa. Comparing the results from the two methods shows that the composition of the equilibrium plasma is strongly influenced by the choice of the hypotheses on the internal temperatures. In the light of experimental measures of internal temperatures reported in the literature, we carry out an analysis of the theoretical hypothesis used herein. [Journal translation]