The Reactive Thermal Conductivity of Thermal Equilibrium and Nonequilibrium Plasmas: Application to Nitrogen

The accuracy of numerical simulation on plasma behavior depends strongly on the reliability of thermophysical property data. Large number of studies for thermal plasma properties in the local thermodynamic equilibrium (LTE) exist; however, the database for thermal nonequilibrium plasmas is still far from completeness. This paper derives a general expression of total reactive thermal conductivity (TRTC) with great applicability to monatomic, diatomic, and polyatomic gases in terms of a two-temperature model. The derived formula is applied to nitrogen plasmas under thermal equilibrium and nonequilibrium conditions, considering its wide use in plasma systems and switching devices. Typical calculated results of TRTC with two different Saha equations and Guldberg-Waage equations in the temperature range of 300 K-40 000 K under different degrees of nonequilibrium are given and compared with those computed according to Brokaw and Butler's derivation for the special case of LTE plasmas, which shows excellent agreement. The influence of different expressions for Saha equations and Guldberg-Waage equations, together with different pressures of 0.1, 1, 3, 5, and 10 atm, on the TRTC evaluated by this newly developed expression is presented as well. These provide reliable reference data for use in the simulation of plasmas.

[1]  E. Levin,et al.  Collision integrals for the interaction of the ions of nitrogen and oxygen in a plasma at high temperatures and pressures , 1992 .

[2]  Peeters,et al.  Thermodynamic generalization of the Saha equation for a two-temperature plasma. , 1989, Physical review. A, General physics.

[3]  L. A. Milone,et al.  Partition Functions of the Light Elements (H to Na), A Revision , 1998 .

[4]  D. Iddles,et al.  Characterization of a twin-torch transferred dc arc , 1995 .

[5]  J. W. Spencer,et al.  Thermophysical properties of nitrogen plasmas under thermal equilibrium and non-equilibrium conditions , 2011 .

[6]  A. Gleizes,et al.  Calculation of a two-temperature plasma composition : bases and application to SF6 , 1999 .

[7]  D. Pagano,et al.  Transport properties of local thermodynamic equilibrium hydrogen plasmas including electronically excited states. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[8]  P. André,et al.  Influence of the Excited States of Atomic Nitrogen N(2D), N(2P) and N(R) on the Transport Properties of Nitrogen. Part II: Nitrogen Plasma Properties , 2007 .

[9]  R. S. Devoto.  Transport coefficients of ionized argon , 1973 .

[10]  Anthony B. Murphy,et al.  Treatment of non-equilibrium phenomena in thermal plasma flows , 2008 .

[11]  E. Pfender,et al.  Thermodynamic and Transport Properties of Two-Temperature Nitrogen-Oxygen Plasma , 2008 .

[12]  B. Smirnov,et al.  Resonant charge exchange involving electronically excited states of nitrogen atoms and ions , 2006 .

[13]  D. Pagano,et al.  Electronically excited states and transport properties of thermal plasmas: the reactive thermal conductivity. , 2002 .

[14]  V. Colombo,et al.  Thermodynamic and transport properties in non-equilibrium argon, oxygen and nitrogen thermal plasmas , 2008 .

[15]  D. Pagano,et al.  High temperature Mars atmosphere. Part I: transport cross sections , 2009 .

[16]  J. W. Spencer,et al.  Thermophysical Properties of High-Temperature Reacting Mixtures of Carbon and Water in the Range 400–30,000 K and 0.1–10 atm. Part 1: Equilibrium Composition and Thermodynamic Properties , 2012, Plasma Chemistry and Plasma Processing.

[17]  J. W. Spencer,et al.  Thermophysical properties of carbon–argon and carbon–helium plasmas , 2011 .

[18]  Savino Longo,et al.  Collision Integrals of High-Temperature Air Species , 2000 .

[19]  J. B. Shumaker,et al.  Observations of departures from equilibrium in a nitrogen arc , 1969 .

[20]  E. Pfender,et al.  Non-equilibrium modelling of an oxygen-plasma cutting torch , 2007 .

[21]  C. F. Curtiss,et al.  Molecular Theory Of Gases And Liquids , 1954 .

[22]  J. Bacri,et al.  Calculation of some thermodynamic properties of air plasmas: Internal partition functions, plasma composition, and thermodynamic functions , 1987 .

[23]  A. Murphy.  Transport coefficients of air, argon-air, nitrogen-air, and oxygen-air plasmas , 1995 .

[24]  P. Fauchais,et al.  Transport coefficients including diffusion in a two-temperature argon plasma , 2002 .

[25]  A. Eletskii,et al.  Resonant charge exchange and relevant transport cross sections for excited states of oxygen and nitrogen atoms , 2004 .

[26]  P. Mayr,et al.  Plasma-assisted nitriding of aluminum , 1994 .

[27]  R. Brokaw,et al.  Thermal Conductivity of Gas Mixtures in Chemical Equilibrium , 1957 .

[28]  Xi Chen,et al.  The reactive thermal conductivity for a two-temperature plasma , 2003 .

[29]  R. Oppermann.  Molecular spectra and molecular structure. I. Diatomic molecules , 1940 .

[30]  R. S. Devoto.  Transport Properties of Ionized Monatomic Gases , 1966 .

[31]  B. Izrar,et al.  Transport coefficients in thermal plasma. Applications to Mars and Titan atmospheres , 2010 .

[32]  R. S. Devoto.  Simplified Expressions for the Transport Properties of Ionized Monatomic Gases , 1967 .

[33]  Effect of electronic excited states on transport in magnetized hydrogen plasma , 2007 .

[34]  A. Murphy,et al.  Transport coefficients of argon, nitrogen, oxygen, argon-nitrogen, and argon-oxygen plasmas , 1994, Plasma Chemistry and Plasma Processing.

[35]  A. B. Cambel,et al.  Partition Functions and Thermodynamic Properties of Nitrogen and Oxygen Plasmas , 1965 .

[36]  J. Aubreton,et al.  Influence of the Excited States of Atomic Nitrogen N(2D) and N(2P) on the Transport Properties of Nitrogen. Part I: Atomic Nitrogen Properties , 2007 .

[37]  A. Murphy.  Transport Coefficients of Hydrogen and Argon–Hydrogen Plasmas , 2000 .

[38]  G. Herzberg,et al.  Molecular Spectra and Molecular Structure , 1992 .

[39]  G. Herzberg.  Molecular Spectra and Molecule Structure. I. Diatomic Molecules. , 1940 .