Derivation of a consistent multi-internal-temperature model for vibrational energy excitation and dissociation of molecular nitrogen in hypersonic flows

Guy, Aurélien; Perrin, Marie‐Yvonne; Bourdon, Anne

doi:10.2514/6.2013-194

Cited by 10 publications

(9 citation statements)

References 16 publications

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“…Finally, the H1 test case studied in this section presents a different behavior from the FIRE 2 test case investigated in [51]; the high-lying levels are depleted slowly contrary to the FIRE 2 test case where the VDF quickly reaches Boltzmann equilibrium. However, the reduced model with two temperatures is able to predict the VDF, and then allows to predict the nonequilibrium of the flow for the H1 test-case.…”

Section: Resultsmentioning

confidence: 99%

“…In the macroscopic model obtained, energy exchange terms and macroscopic rate coefficients are derived self-consistently from a state to state database [51,52]. Recently, this model was successfully applied to FIRE 2 flight conditions where relaxation and dissociation processes are relatively fast due to a very high translational temperature [51]. In this work, we apply this model to a low earth orbit return condition where the translational temperature is lower and nonequilibrium processes dominate in the entire shock layer.…”

Section: Multi-internal-temperature Modelsmentioning

confidence: 99%

“…In this section, we propose to use several internal vibrational temperatures to better represent the vibrational nonequilibrium of a molecular flow. In the macroscopic model obtained, energy exchange terms and macroscopic rate coefficients are derived self-consistently from a state to state database [51,52]. Recently, this model was successfully applied to FIRE 2 flight conditions where relaxation and dissociation processes are relatively fast due to a very high translational temperature [51].…”

Section: Multi-internal-temperature Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Reduction of State-to-State to Macroscopic Models for Hypersonics

Bourdon¹,

Annaloro²,

Bultel³

et al. 2014

TOPPJ

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Four different types of macroscopic models developed for the vibration-chemistry coupling in nonequilibrium flows for re-entry applications are presented. First, using an approach based on nonequilibrium thermodynamics, global rate coefficients of dissociation of N 2 and O 2 under parent molecular or atomic impact and backward molecular recombination are determined. Then a Two-Level Distribution (TLD) model is developed, in which a relaxation equation for vibrational temperature is solved as in the case of multi-temperature models but with the simultaneous solution of a kinetic equation, as in the case of state-to-state models, but only for the last vibrational level. In a third approach, a multiinternal temperature model is presented to describe accurately the vibrational distribution function in using several groups of levels, within which the levels are assumed to follow a Boltzmann distribution at an internal temperature of the group. This multi-internal temperature model allows us to describe accurately the vibrational energy relaxation and dissociation processes behind a strong shock wave. Finally, a rovibrational collisional coarse-grain model is developed to reduce a detailed rovibrational mechanism for the internal energy excitation and dissociation processes behind a strong shock wave in a nitrogen flow.

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Section: Resultsmentioning

confidence: 99%

Section: Multi-internal-temperature Modelsmentioning

confidence: 99%

Section: Multi-internal-temperature Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Reduction of State-to-State to Macroscopic Models for Hypersonics

Bourdon¹,

Annaloro²,

Bultel³

et al. 2014

TOPPJ

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show abstract

“…Among developing computational models the most famous are the multi-temperature and collisional-radiative (CR) models, [29][30][31][32][33][34][35][36][37][38][39] which describe numerous physical and chemical processes in the high-temperature gases behind shock wave fronts. It is important also, that the use of CR models stimulate development of quantum-mechanical, quantum-chemical and quantum-statistical models of elementary physical and chemical processes applied to problems of physical mechanics.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Two Hybrid RC-Models for Prediction of Nonequilibrium Radiation from Strong Shock Waves

Суржиков

2015

45th AIAA Thermophysics Conference

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Numerical simulation data for nonequilibrium spectral emissivity of shock-heated air in absolute units were obtained using two models of nonequilibrium radiation emitted in the relaxation zone. The first model is based on the Euler equations for shock wave front and it is formulated for one dimensional problem of the "shock tube". The second model is based on the two-dimensional Navier-Stokes equations for viscid shock layer near blunted body in hypersonic flow. General discussion in the paper is dedicated to the following question of practical interest: how to interpret measured and calculated data for the problem of "shock tube" to use these data for prediction of radiative heating of hyperbolic re-entry vehicles. All calculation results are compared with flight data for experimental reentry space vehicle Fire-II.

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“…The multi-temperature approach to thermal non-equilibrium results from associating a different temperature to individual degrees of freedom. A more general multi-internal-temperature approach [24], using several temperatures to describe different energy ranges of the ISD of a single degree of freedom, is also possible but it is not considered in this paper.…”

Section: Numerical Modelmentioning

confidence: 99%

Advanced Models in Shock Waves

Colonna¹,

Ammando²,

Dikalyuk³

et al. 2014

TOPPJ

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Abstract:The paper presents three collisional-radiative models developed to investigate non-equilibrium chemistry and radiation in hypersonic shock tubes operating with different planetary atmospheres. An hybrid collisional-radiative model, employing the state-to-state kinetics of electronically excited states of molecules and the multi-temperature approximation for the vibrational degree of freedom is presented first, and applied to the numerical rebuilding of experimental shock tube emission spectra. Next, an hybrid collisional-radiative model for ionized air is presented. This model consider the state-tostate approach for electronic states of atoms and the multi-temperature model for the vibrational populations of diatomic molecules in their ground electronic state. A radiative transport equation is also solved to determine radiative source terms in the kinetic scheme and the enthalpy production due to radiation. The third model considers the state-to-state collisionalradiative model of Jupiter's atmosphere, self-consistently coupled with the Boltzmann equation for free electrons and the radiative transfer equation for the radiation transport in one-dimensional slab geometry.

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Derivation of a consistent multi-internal-temperature model for vibrational energy excitation and dissociation of molecular nitrogen in hypersonic flows

Cited by 10 publications

References 16 publications

Reduction of State-to-State to Macroscopic Models for Hypersonics

Reduction of State-to-State to Macroscopic Models for Hypersonics

Comparison of Two Hybrid RC-Models for Prediction of Nonequilibrium Radiation from Strong Shock Waves

Advanced Models in Shock Waves

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