Untitled

Thermodynamic and transport properties of two-temperature oxygen plasmas are presented. Variation of species densities, mass densities, specific heat, enthalpy, viscosity, thermal conductivity, collision frequency and electrical conductivity as a function of temperature, pressure and different degree of temperature non-equilibrium are computed. Reactional, electronic and heavy particle components of the total thermal conductivity are discussed. To meet practical needs of fluid-dynamic simulations, temperatures included in the computation range from 300 K to 45,000 K, the ratio of electron temperature (T e ) to the heavy particle temperature (T h ) ranges from 1 to 30 and the pressure ranges from 0.1 to 7 atmospheres. Results obtained for thermodynamic equilibrium (T e = T h ) under atmospheric pressure are compared with published results obtained for similar conditions. Observed overall agreement is reasonable. Slight deviations in some properties may be attributed to the values used for collision integral data and for the two temperature formulations used. An approach for computing properties under chemical nonequilibrium and associated deviations from two-temperature results under similar conditions are discussed.

Section: Introductionmentioning

confidence: 90%

Thermodynamic and Transport Properties of Two-temperature Oxygen Plasmas

Ghorui

Heberlein

Pfender

2007

“…Collision integrals are required to calculate transport coefficients [8][9][10] and are defined as follows, assuming that colliding species i and j are in their respective ground states:…”

Section: Collision Integralsmentioning

confidence: 99%

“…Consequently, we developed a new theory [8][9][10] that allows us to rigorously account for the diffusion which can be extended to thermodynamic of non-equilibrium. However the transport properties of electrons are treated differently but they are always coupled to these of heavy species.…”

Section: Introductionmentioning

confidence: 99%

“…This new theory is based on the solution of Boltzmann's equation using the Chapman-Enskog method. Therefore the transport properties use, in comparison to the formalism that is done elsewhere [8][9][10], the same grandeurs as those taken into account in previous theories: the collision integrals " Q ';s ð Þ . The purpose of this paper is to determine the transport coefficients in equilibrium water plasma.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transport Coefficients in Water Plasma: Part I: Equilibrium Plasma

Aubreton

Elchinger

Vinson

2009

Self Cite

Knowledge of the transport coefficients of steam water plasma is important for modeling plasma flow processes and heat transfer. In this study, calculations of these properties were performed in a temperature range from 400 to 30,000 K and at pressures of 0.5, 1.0, 5.0 and 10 bar. Herein the composition of water plasma was determined at equilibrium. First, the most recent data on potential interactions and elastic differential cross sections for interacting particles were carefully examined in order to choose those most appropriate for determining the collision integrals. Second, we restricted the number of species to ten (e, H, O, H ? , O ? , O ?? , H 2 , O 2 , OH and H 2 O) and tested our collision integrals by comparing the thermal conductivity and viscosity to experimental data for water (at low temperatures). Finally, the total thermal conductivity, viscosity and electrical conductivity were calculated for different pressures.

“…The indices (', s) are directly related to the order of the approximation used for the transport coefficients: viscosity, electrical conductivity, translational and reactional thermal conductivities are calculated at the third approximation and internal thermal conductivity is obtained at the first approximation [8][9][10]. A previous study [9] has shown that all combinations of numbers (', s) have to be calculated for " Q ';s ð Þ i;j up to ' max ¼ 3 and s max ¼ 5, provided ' s. The transport cross sections Q ð'Þ i;j are determined from internuclear interaction potential, quantum approach and directly by numerical integration of differential cross sections.…”

Section: Collision Integralsmentioning

confidence: 99%

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

Sourd

André

Aubreton

et al. 2007

Self Cite

In this paper, the calculated values of the viscosity and thermal conductivity of nitrogen plasma are presented taking into account five (e, N, N + , N 2 and N 2 + ) or eight (e, N( 4 S), N( 2 P), N( 2 D), N(R), N + , N 2 and N 2 + ) species. The calculations are based on the supposition that the temperature dependent probability of occupation of the states is given by the Boltzmann factor. The domain for which the calculations are performed, is for p = 1 and 10 atm in the temperature range from 5,000 K to 15,000 K. Classical collision integrals are used in calculating the transport coefficients and we have introduced new averaged collision integrals where the weight associated at each interacting species pair is the probable collision frequency. The influence of the collision integral values and energy transfer between two different species is studied. These results are compared which those of published theoretical studies.