Computation of net emission of - thermal plasmas

Abstract

Assuming local thermodynamic equilibrium (LTE), the total radiation which escapes from a - plasma is calculated in the temperature range between 5000 and 30 000 K. The evaluation of the net emission coefficient is performed by solving the radiative transfer equation in a cylindrical isothermal plasma taking into account line broadening phenomena. The radiation emission of methane depends mainly on the carbon species, whereas the presence of hydrogen in the mixture leads to a radiation decrease especially at high temperatures.

Net emission coefficient of air thermal plasmas

“…The methods for calculating the emission or absorption coefficients relative to these mechanisms were given in previous papers (see, e.g. [5]). The application of these methods to nitrogen and oxygen needs some basic data.…”

“…It has been demonstrated that the use in the energy equation of a net emission coefficient (NEC) defined by Lowke [1] as the divergence of the radiative flux at the centre of an isothermal sphere, allows to compute with a satisfactory accuracy, the temperature of the hottest regions of the plasma [2]. As the maximum temperature is often higher than 10 000 K, the radiation of the hottest regions is mainly due to atomic species (neutrals and ions); in these conditions the NEC was calculated taking only into account the atomic species, even for plasmas created in molecular gases [3][4][5].…”

Net emission coefficient for CO–H2 thermal plasmas with the consideration of molecular systems

“…The atomic continuum theory was thoroughly studied in the previous papers of Gleizes et al [77], Liani et al [78] and Cressault [79].…”

Numerical Investigation of a Local Oxygen Injection Effect on Argon Induction Plasmas Using a Chemically Non-Equilibrium Model

“…The radiative intensities of argon and oxygen were taken from the literature (Miller and Ayen, 1969;Krey and Morris, 1970;Liani, 1997). Table 1 summarizes the reactions in the argonoxygen plasma.…”