Composition and thermodynamic properties of air thermal plasmas mixed with ablated Copper and polytetrafluoroethylene vapor

In order to study the characteristic of fault arc in aircraft electrical system, this paper is devoted to calculate chemical equilibrium composition and thermodynamic properties (mass density, enthalpy and specific heat at constant pressure) of reacting mixtures contained by air, Cu and polytetrafluoroethylene at temperatures of 300–3000 K and pressures of 0.02–0.1 MPa and simulate the corresponding arc process. Under the assumption of local thermodynamic equilibrium, chemical equilibrium composition is solved by the method of Gibbs free energy minimization together with Lagrange multiplier. Debye-Huckel corrections are applied to the free energies of ionized species. Thermodynamic properties are obtained by the standard thermodynamic relationships.