Experimental Measurements of Nonequilibrium and Equilibrium Radiation From Planetary Atmospheres

Thomas, George; Menard, W. A.

doi:10.2514/6.1964-1314

Cited by 7 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 47 shows the time-response characteristics of the non-equilibrium radiation peak as function of velocity, for CO(4+) radiation at a wavelength of 200 nm and the bands system CN (violet) radiation measured in ADST. In this figure, tm denotes the time for which the maximum radiation is reached, while t qst is the characteristic non-equilibrium radiation peak duration), this figure shows also similar measurements taken from [41]. The peak radiation intensity of CO(4+) measured in ADST compared against calculated values is plotted as function of shock velocity in Figure 48.…”

Section: X2supporting

confidence: 52%

Survey of CO2 Radiation Experimental Data in Relation with Planetary Entry

Reynier

2021

Galaxies

View full text Add to dashboard Cite

This paper focuses on a survey of experimental data related to radiation into CO2 plasma flows, which are encountered during Mars and Venus entries. The review emphasizes on VUV and IR radiation, since recent experimental efforts has been devoted to these wavelength ranges since they contribute mostly to CO2 plasma radiation. The main objective of the study is to identify the most attractive datasets for future crosscheck comparisons with the results obtained during future test campaigns with ESTHER shock-tube. The survey accounts for the results obtained in shock-tubes, expansion tube and plasma arc-jets for Mars and Venus test campaigns. The experimental results obtained for propulsion related studies have also been considered.

show abstract

Section: X2supporting

confidence: 52%

Survey of CO2 Radiation Experimental Data in Relation with Planetary Entry

Reynier

2021

Galaxies

View full text Add to dashboard Cite

show abstract

“…This comparison is performed for the time moments t = 1634 s (Figs.21-23) and t = 1639 s (Figs. [24][25][26]. Legitimate differences exist in the nonequilibrium relaxation zone.…”

Section: Numerical Simulation Resultsmentioning

confidence: 99%

“…In the last decade we were witnessed the advent of large amount of experimental data on the absolute values of the spectral intensity of radiation in different gas mixtures (air, mixtures of CO 2 -N 2 and CH 4 -N 2 ), obtained by using high-speed cameras. Results of the first experiments [24][25][26][27][28] also remain in the attention of scientists and engineers developing the theoretical and experimental methods for studying structure of strong shock waves. These experimental data obtained using shock tubes, and currently used to validate the computational and theoretical models.…”

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

View full text Add to dashboard Cite

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.

show abstract

“…A number of papers were dedicated to the nonequilibriu m kinetics [1][2][3][4][5][6][7][8][9][10][11] and nonequilibriu m radiation 8,9,11,12 . The most important features of the process were understood, the models were proposed that were able to reproduce existing at that mo ment experimental data.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium Radiation behind the Strong Shock Waves in Marsian and Titan Atmospheres: Numerical Rebuilding of Experimental Data

Dikalyuk

Суржиков

Shatalov

et al. 2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

View full text Add to dashboard Cite

The computati onal model of nonequili brium radi ation emitted in the relaxati on zone behind shock front is presented in the paper. The hydrodynamic description of relaxati on zone is performed in the framework of Euler equations. The model includes different physical chemical processes such as chemical kinetics, relaxati on of vi brational energy. Also the equation for the determinati on of electron gas temperature is solved. The "justoverl appi ng" line model is used for the calculation of the s pectral emissivity. The presented model is used in order to obtain vari ous characteristics of radiation (spectral emissivity, spatial distri buti on of s pectral emissivity integrated over s pecific wavelength region, maxi mum val ue of the nonequili brium radi ation) behind shock front for the conditi ons which are relevant to the experi mental data obtained on different facilities. Comparison of experi mental and theoretical data is presented in the paper. The reasons for the discrepancies are discussed. Nomenclature x = distance behind the shock front p = pressure ρ = density u = velocity T = translational temperature of the heavy particles x i = mo lar fract ion of i-th chemical co mponent m i = mass of i-th chemical co mponent T V,i,j = vibrational temperature of j-th mode of i-th molecu le θ i,j = characteristic vibrational temperature of j-th mode of i-th mo lecule g i,j = degeneracy of j-th mode of i-th molecu le N s = total number of chemical co mponents N M = number of diato mic and triato mic molecu les among chemical co mponentslar concentrations of i-th chemical co mponent k f i , k r i = forward and reverse rate constant of i-th chemical react ion N r = total number of chemical react ions a ij , b ij = stoichiometric coefficients of the j-th forward and reverse reactions for the i-th chemical co mponent K eq i = equilibriu m constant of i-th reaction e m , e 0 m = number of v ibrational quanta of the m-th vib rational mode and equilibriu m (with translational 2 temperature) nu mber of vibrat ional quanta of the m-th vibrat ional mode Q m VT = term accounting for the translational-vibrational energy exchange of the m-th vibrat ional mode Q m CV = term accounting for the loss and gain of vibrational quanta due to chemical reactions in which the mth vibrational mode participate N VT,m = total number of VT reactions τ m = relaxation time of the m-th vibrational mode τ m,i = relaxation time of the m-th vibrational mode in the i-th VT react ion n e = volume concentration of electrons T e = temperature of electron gas Q ei = term accounting for the contribution of electron-ion collisions to the change of the energy of electron gas Q ea = term accounting for the contribution of electron-atom collisions to the change of the energy of electron gas Q ai = term accounting for the contribution of associative ionization and dissociative recomb ination reactions to the change of the energy of electron gas Q ion = term accounting for the contribution of ionization reactions to the change of the energy of electron gas Q ...

show abstract

Experimental Measurements of Nonequilibrium and Equilibrium Radiation From Planetary Atmospheres

Cited by 7 publications

References 6 publications

Survey of CO2 Radiation Experimental Data in Relation with Planetary Entry

Survey of CO2 Radiation Experimental Data in Relation with Planetary Entry

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

Nonequilibrium Radiation behind the Strong Shock Waves in Marsian and Titan Atmospheres: Numerical Rebuilding of Experimental Data

Contact Info

Product

Resources

About