Supersonic Argon Flow In An Arc Plasma Source. [AIP Conference Proceedings 812, 355 (2006)]. B. I... more Supersonic Argon Flow In An Arc Plasma Source. [AIP Conference Proceedings 812, 355 (2006)]. B. Izrar, M. Dudeck, P. André, MF Elchinger, J. Aubreton. Abstract. The plasma properties inside a DC arc‐jet operating with argon ...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 12, 2010
The inductively coupled plasma torch of the Laboratoire Arc Electrique et Plasma Thermique (LAEPT... more The inductively coupled plasma torch of the Laboratoire Arc Electrique et Plasma Thermique (LAEPT) is used to generate plasma at atmospheric pressure in order to investigate the radiation behavior of different plasma flows in chemical and thermal equilibrium. In the present study, the determination of the local specific enthalpy was assessed in order to compare results of optical emission spectroscopy. The comparison is realized using an enthalpy probe of Institut fur Raumfahrtsysteme (IRS) of the University of Stuttgart. However, the original approach of the enthalpy probe could not be applied, but the measured heat flux was interpreted in terms of forced convection of the hot plasma to the cooled copper surface. Following this theory, the flow temperature in thermal and chemical equilibrium can be determined which compares very well to the measured temperatures using Mach-Zehnder-Interferometry.
Knowledge of thermodynamic properties as well as parameters such as energy density and power flow... more Knowledge of thermodynamic properties as well as parameters such as energy density and power flow is important for modeling thermal plasmas of fluoroalkylamine-air mixtures. In this paper, these thermodynamic properties of fluoroalkylamine-air mixture plasmas are calculated in a temperature range of 500 K to 20,000 K at atmospheric pressure and local thermodynamic equilibrium (LTE). The Gibbs free energy minimization method is used to determine the chemical equilibrium compositions of the plasmas that are needed to calculate the thermodynamic properties. These thermodynamic properties are then used to calculate the energy density and power flow of these plasmas. The variation of the energy density is related to the variations of the density and mass enthalpy. We notice that, this energy density increases with the percentage of air in the mixture for temperatures higher than 7000 K. The power flow, which depends also on density, enthalpy mass and sound speed, increases with the percentage of air in the same temperature range. Energy density and power flow results show that increasing air percentage in the mixture can be more interesting for damaging gaseous chemical species such as CF 2 , CO, HCN, and HF appearing at low temperatures with high concentrations.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 28, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
In this paper, the composition calculation in plasma out of thermal equilibrium is discussed and ... more In this paper, the composition calculation in plasma out of thermal equilibrium is discussed and we test the viscosity formulations of Wilke, Gupta et al, Chapman Enskog and Sutherland in air plasma out of thermal equilibrium. Finally we applied the formulations to Fire II reentry.
HAL (Le Centre pour la Communication Scientifique Directe), 1999
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 26, 2008
... 1 Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico, Avenida Rovisco Pais, 10... more ... 1 Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico, Avenida Rovisco Pais, 1049001 Lisboa, Portugal 2 Laboratoire Arc Électrique et Plasmas Thermiques, CNRS, UMR 6069, 24 Avenue des Landais, F63177 Aubi`ere Cedex, France 3 Laboratoire d ...
HAL (Le Centre pour la Communication Scientifique Directe), Dec 11, 2014
We have performed a new efficient method to calculate numerically the transport coefficients at h... more We have performed a new efficient method to calculate numerically the transport coefficients at high temperature. The collision theory was treated to study singularities that occur when evaluating the collision cross section. The transport coefficients (viscosity, diffusion coefficient, thermal and electrical conductivity) depend strongly on nature of the interaction between the particles that form the plasma and that is why it is necessary to determine the interaction potential accurately.
Zenodo (CERN European Organization for Nuclear Research), 2016
With the Gibbs free energy method, we determine the molar fraction in a plasma at and out of ther... more With the Gibbs free energy method, we determine the molar fraction in a plasma at and out of thermal equilibrium consisting of air and aluminum for several percentages in the temperature range of 500-6000 K. We take three temperatures into account (T rot = T h ; T vib ; T ex = T e). We indicate the formulae and the numerical method used to perform the calculation taking three condensed phases AlN, Al, Al 2 O 3 into account. We show that the air percentage plays a major role to create these phases. We clarify the role plays on the vaporization temperatures and on the sublimation temperature by the non-thermal equilibrium of the plasma. This kind of plasma is found in arc roots, near a wall, in plasmas with a high value of electrical field,… The influence of the pressures until 30 9 10 5 Pa. is shown on molar fraction of the chemical species, on the vaporization temperatures and on the sublimation temperature. The vaporization temperatures are given versus the thermal non equilibrium versus various mixtures (air, aluminum) and versus the pressures (10 5 Pa-30 9 10 5 Pa).
Supersonic Argon Flow In An Arc Plasma Source. [AIP Conference Proceedings 812, 355 (2006)]. B. I... more Supersonic Argon Flow In An Arc Plasma Source. [AIP Conference Proceedings 812, 355 (2006)]. B. Izrar, M. Dudeck, P. André, MF Elchinger, J. Aubreton. Abstract. The plasma properties inside a DC arc‐jet operating with argon ...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 12, 2010
The inductively coupled plasma torch of the Laboratoire Arc Electrique et Plasma Thermique (LAEPT... more The inductively coupled plasma torch of the Laboratoire Arc Electrique et Plasma Thermique (LAEPT) is used to generate plasma at atmospheric pressure in order to investigate the radiation behavior of different plasma flows in chemical and thermal equilibrium. In the present study, the determination of the local specific enthalpy was assessed in order to compare results of optical emission spectroscopy. The comparison is realized using an enthalpy probe of Institut fur Raumfahrtsysteme (IRS) of the University of Stuttgart. However, the original approach of the enthalpy probe could not be applied, but the measured heat flux was interpreted in terms of forced convection of the hot plasma to the cooled copper surface. Following this theory, the flow temperature in thermal and chemical equilibrium can be determined which compares very well to the measured temperatures using Mach-Zehnder-Interferometry.
Knowledge of thermodynamic properties as well as parameters such as energy density and power flow... more Knowledge of thermodynamic properties as well as parameters such as energy density and power flow is important for modeling thermal plasmas of fluoroalkylamine-air mixtures. In this paper, these thermodynamic properties of fluoroalkylamine-air mixture plasmas are calculated in a temperature range of 500 K to 20,000 K at atmospheric pressure and local thermodynamic equilibrium (LTE). The Gibbs free energy minimization method is used to determine the chemical equilibrium compositions of the plasmas that are needed to calculate the thermodynamic properties. These thermodynamic properties are then used to calculate the energy density and power flow of these plasmas. The variation of the energy density is related to the variations of the density and mass enthalpy. We notice that, this energy density increases with the percentage of air in the mixture for temperatures higher than 7000 K. The power flow, which depends also on density, enthalpy mass and sound speed, increases with the percentage of air in the same temperature range. Energy density and power flow results show that increasing air percentage in the mixture can be more interesting for damaging gaseous chemical species such as CF 2 , CO, HCN, and HF appearing at low temperatures with high concentrations.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 28, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
In this paper, the composition calculation in plasma out of thermal equilibrium is discussed and ... more In this paper, the composition calculation in plasma out of thermal equilibrium is discussed and we test the viscosity formulations of Wilke, Gupta et al, Chapman Enskog and Sutherland in air plasma out of thermal equilibrium. Finally we applied the formulations to Fire II reentry.
HAL (Le Centre pour la Communication Scientifique Directe), 1999
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 26, 2008
... 1 Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico, Avenida Rovisco Pais, 10... more ... 1 Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico, Avenida Rovisco Pais, 1049001 Lisboa, Portugal 2 Laboratoire Arc Électrique et Plasmas Thermiques, CNRS, UMR 6069, 24 Avenue des Landais, F63177 Aubi`ere Cedex, France 3 Laboratoire d ...
HAL (Le Centre pour la Communication Scientifique Directe), Dec 11, 2014
We have performed a new efficient method to calculate numerically the transport coefficients at h... more We have performed a new efficient method to calculate numerically the transport coefficients at high temperature. The collision theory was treated to study singularities that occur when evaluating the collision cross section. The transport coefficients (viscosity, diffusion coefficient, thermal and electrical conductivity) depend strongly on nature of the interaction between the particles that form the plasma and that is why it is necessary to determine the interaction potential accurately.
Zenodo (CERN European Organization for Nuclear Research), 2016
With the Gibbs free energy method, we determine the molar fraction in a plasma at and out of ther... more With the Gibbs free energy method, we determine the molar fraction in a plasma at and out of thermal equilibrium consisting of air and aluminum for several percentages in the temperature range of 500-6000 K. We take three temperatures into account (T rot = T h ; T vib ; T ex = T e). We indicate the formulae and the numerical method used to perform the calculation taking three condensed phases AlN, Al, Al 2 O 3 into account. We show that the air percentage plays a major role to create these phases. We clarify the role plays on the vaporization temperatures and on the sublimation temperature by the non-thermal equilibrium of the plasma. This kind of plasma is found in arc roots, near a wall, in plasmas with a high value of electrical field,… The influence of the pressures until 30 9 10 5 Pa. is shown on molar fraction of the chemical species, on the vaporization temperatures and on the sublimation temperature. The vaporization temperatures are given versus the thermal non equilibrium versus various mixtures (air, aluminum) and versus the pressures (10 5 Pa-30 9 10 5 Pa).
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Papers by Andre Pascal