Mixing rules for thermal plasma properties in mixtures of argon, air and metallic vapours

Abstract

Modelling of electric arcs and thermal plasmas in mixtures of gases and vapours needs prior knowledge of rather large data banks corresponding to thermodynamic functions, transport coefficients and radiation properties. For a given pressure these data are functions of temperature and gas proportions in the mixture. In order to reduce the memory or because some properties of the mixtures are not known, some mixing laws can be useful. These mixing rules allow estimation of the properties of the mixtures when only the corresponding properties of the pure gases or vapours are known. In this paper we study several mixing rules for mixtures of argon or air with metallic vapours. Simple laws such as linear interpolations are compared with relations deduced from physical consideration and some general behaviour is given in conclusion: mixing rules for electrical conductivity, viscosity and net emission coefficient are good. For other properties the use of a mixing law may produce rather large errors.

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

“…As a consequence of that, it is not possible to correctly model the thermal plasma's applications since we need complete databanks. To solve this problem, we either do interpolations of data to obtain the intermediate properties for a given mixture, or we use mixing rules 107 to determine the properties of a mixture from data of pure gases. Nevertheless, due to lack of data, there are still few physical phenomena which cannot be taken into account in the numerical models.…”

Design-Oriented Modelling of Different Quenching Solutions in Induction Plasma Synthesis of Copper Nanoparticles

“…The volumetric radiative loss was obtained by linear interpolation of the Net Emission Coefficients based the molar fractions of Ar and Cu vapour, as suggested by Gleizes et al [18].…”

A Simulative and Experimental Approach for the Design and Optimization of Atmospheric Pressure Low Power RF Thermal Plasma Processes

“…To calculate the thermodynamic and transport properties of the gas mixture and the corresponding radiative losses, the contributions from both Ar and air are taken into account, using data from Murphy et al and Cressault et al The volumetric radiative loss R was obtained by linear interpolation of the Net Emission Coefficients based on the molar fractions of Ar and air, as suggested by Cressault et al…”

“…To calculate the thermodynamic and transport properties of the gas mixture and the corresponding radiative losses, the contributions from both Ar and air are taken into account, using data from Murphy et al [27] and Cressault et al [28,29] The volumetric radiative loss R was obtained by linear interpolation of the Net Emission Coefficients based on the molar fractions of Ar and air, as suggested by Cressault et al [30] The terms concerning the electromagnetic field and the radiative losses were implemented in the model using suitable user-defined functions written in the C language, then using the commercial software ANSYS FLUENTß to solve fluid equations.…”