Thermodynamic and transport properties of high temperature Mars atmosphere have been calculated in the pressure range (0.01-100) bar and in the temperature range (100-50000) K. Planetary explorations require an accurate analysis of entry or re-entry conditions for vehicles. For this reason reliable and consistent data sets of thermodynamic and transport properties are needed for numerical simulations. Results have been obtained by using a self-consistent approach for the thermodynamic properties and higher order approximation of the Chapman-Enskog method for the transport coefficients. Debye-Hückel corrections have been considered in the thermodynamic properties while collision integrals of charge-charge interactions have been obtained by using a screened Coulomb potential. The atmosphere is a mixture of 53 components and electronic energies as well as spectroscopic data of the most important diatomic molecules used for calculations can be found in, while for atomic species, the cutoff selected is the largest between the Fermi and Griem values. It must be pointed out that the Griem cutoff depends on the plasma composition making necessary a self- consistent solution of the problem. Plasma compositions have been performed by using a hierarchical method. In order to calculate transport properties, elastic collision integrals for neutral-neutral and neutral-ion interactions are calculated by means of a phenomenological approach and inelastic collision integrals, due to resonant charge exchange channels, have been considered. Mars compositions, specific enthalpies and entropies, mean molar mass, specific heat, isentropic coefficient, total thermal and electric conductivities and viscosity are presented as function of temperature for different pressures.

High temperature transport and thermodynamic properties of equilibrium Mars atmosphere

D'ANGOLA, Antonio;
2011-01-01

Abstract

Thermodynamic and transport properties of high temperature Mars atmosphere have been calculated in the pressure range (0.01-100) bar and in the temperature range (100-50000) K. Planetary explorations require an accurate analysis of entry or re-entry conditions for vehicles. For this reason reliable and consistent data sets of thermodynamic and transport properties are needed for numerical simulations. Results have been obtained by using a self-consistent approach for the thermodynamic properties and higher order approximation of the Chapman-Enskog method for the transport coefficients. Debye-Hückel corrections have been considered in the thermodynamic properties while collision integrals of charge-charge interactions have been obtained by using a screened Coulomb potential. The atmosphere is a mixture of 53 components and electronic energies as well as spectroscopic data of the most important diatomic molecules used for calculations can be found in, while for atomic species, the cutoff selected is the largest between the Fermi and Griem values. It must be pointed out that the Griem cutoff depends on the plasma composition making necessary a self- consistent solution of the problem. Plasma compositions have been performed by using a hierarchical method. In order to calculate transport properties, elastic collision integrals for neutral-neutral and neutral-ion interactions are calculated by means of a phenomenological approach and inelastic collision integrals, due to resonant charge exchange channels, have been considered. Mars compositions, specific enthalpies and entropies, mean molar mass, specific heat, isentropic coefficient, total thermal and electric conductivities and viscosity are presented as function of temperature for different pressures.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11563/18745
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