Comparison of coupled radiative flow solutions with Project Fire II flight data

Olynick, David R.; Henline, William D.; Chambers, L. H.; Candler, Graham V.

doi:10.2514/3.712

Cited by 85 publications

(29 citation statements)

References 9 publications

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“…For the last fifty years, this latter experiment on the reduced copy of the Apollo space vehicle has been a benchmark for the validation of various thermochemical models. 28,29,32,33,63 While the vibrational relaxation, chemical reactions, and radiation models were widely assessed, 28,32 the effect of electronic excitation still remains unstudied (except the work 27 where highlying electronic energy levels were grouped into one).…”

Section: Application To a Flow Behind Shock Wavementioning

confidence: 99%

“…28,32,63 For the considered trajectory point 1634 s, the convective flux varies from 1.5 to 2.2 MW/m 2 according to the experiments and simulations. 28,32,63 This is in line with our results for the near-equilibrium region at a distance 1-2 cm behind the shock front, where the total heat flux decreases from 3 to 1.5 MW/m 2 for the nitrogen mixture, and from 1.5 to 0.3 MW/m 2 for the oxygen mixture. Thus, we conclude that our model, even being qualitative due to the applied post-processing procedure, provides a satisfactory agreement with the existing experimental and numerical data.…”

Section: B Transport Properties and Heat Fluxesmentioning

confidence: 99%

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Transport coefficients and heat fluxes in non-equilibrium high-temperature flows with electronic excitation

Истомин

Кустова

2017

Physics of Plasmas

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The influence of electronic excitation on transport processes in non-equilibrium high-temperature ionized mixture flows is studied. Two five-component mixtures, N 2 =N þ 2 =N=N þ =e À and O 2 =O þ 2 =O=O þ =e À , are considered taking into account the electronic degrees of freedom for atomic species as well as the rotational-vibrational-electronic degrees of freedom for molecular species, both neutral and ionized. Using the modified Chapman-Enskog method, the transport coefficients (thermal conductivity, shear viscosity and bulk viscosity, diffusion and thermal diffusion) are calculated in the temperature range 500-50 000 K. Thermal conductivity and bulk viscosity coefficients are strongly affected by electronic states, especially for neutral atomic species. Shear viscosity, diffusion, and thermal diffusion coefficients are not sensible to electronic excitation if the size of excited states is assumed to be constant. The limits of applicability for the Stokes relation are discussed; at high temperatures, this relation is violated not only for molecular species but also for electronically excited atomic gases. Two test cases of strongly non-equilibrium flows behind plane shock waves corresponding to the spacecraft re-entry (Hermes and Fire II) are simulated numerically. Fluid-dynamic variables and heat fluxes are evaluated in gases with electronic excitation. In inviscid flows without chemical-radiative coupling, the flow-field is weakly affected by electronic states; however, in viscous flows, their influence can be more important, in particular, on the convective heat flux. The contribution of different dissipative processes to the heat transfer is evaluated as well as the effect of reaction rate coefficients. The competition of diffusion and heat conduction processes reduces the overall effect of electronic excitation on the convective heating, especially for the Fire II test case. It is shown that reliable models of chemical reaction rates are of great importance for accurate predictions of the fluid dynamic variables and heat fluxes. Published by AIP Publishing. [http://dx

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Section: Application To a Flow Behind Shock Wavementioning

confidence: 99%

Section: B Transport Properties and Heat Fluxesmentioning

confidence: 99%

Transport coefficients and heat fluxes in non-equilibrium high-temperature flows with electronic excitation

Истомин

Кустова

2017

Physics of Plasmas

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“…NOVAR, a derivative of LORAN, has been loosely coupled with the aeow solver GIANTS to generate NavierStokes solutions with coupled radiation for comparison with the FIRE II aeight data. 69 Using a tangent slab radiation transport algorithm, a good agreement with the aeight data घtotal stagnation heating and radiative intensityङ over the entry trajectory was obtained; further, radiative coupling lead to a better comparison with the aeight data as compared to an uncoupled simulation. Most calculations with radiation coupling have used a tangent-slab approximation to model the radiation transport; the assumptions of this approximation are valid in the stagnation region of a blunt body aeow.…”

Section: Radiation Couplingmentioning

confidence: 78%

“…The GIANTS code 69 is a laminar, 2-Dèaxisymmetric, full Navier-Stokes code which simulates thermal and chemical nonequilibrium. It was developed to accurately simulate the aeowaeeld and surface boundary conditions characteristic of a pyrolizing or ablating TPS.…”

Section: Gasp घThe General Aerodynamic Simulation Programङmentioning

confidence: 99%

“…The electronic and free-electron translational energy modes घif included at allङ are usually assumed to be in equilibrium with the vibrational modes at temperature T V . घAn exception to this approach is discussed by Olynick, 69 in which electron translational energy modeled as a function of T was found to yield better agreement with experimental data from Project FIRE.ङ Justiaecation for this last assumption in air is based on eaecient energy transfer between electrons and the vibrational modes of molecular nitrogen. The TNE2 model may be implemented in two w a ys.…”

Section: Chemical Kineticsmentioning

confidence: 99%

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Computational aerothermodynamic design issues for hypersonic vehicles

Olynick

Venkatapathy

1997

32nd Thermophysics Conference

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A brief review of the evolutionary progress in computational aerothermodynamics is presented. The current status of computational aerothermodynamics is then discussed, with emphasis on its capabilities and limitations for contributions to the design process of hypersonic vehicles. Some topics to be highlighted include: घ1ङ aerodynamic coeaecient predictions with emphasis on high temperature gas eaeects; घ2ङ surface heating and temperature predictions for thermal protection system घTPSङ design in a high temperature, thermochemical nonequilibrium environment; घ3ङ methods for extracting and extending computational aeuid dynamic घCFDङ solutions for eaecient utilization by all members of a multidisciplinary design team; घ4ङ physical models; घ5ङ validation process and error estimation; and घ6ङ gridding and solution generation strategies. Recent experiences in the design of X-33 will be featured. Computational aerothermodynamic contributions to Mars Pathaender, METEOR, and Stardust घComet Sample returnङ will also provide context for this discussion. Some of the barriers that currently limit computational aerothermodynamics to a predominantly reactive mode in the design process will also be discussed, with the goal of providing focus for future research.

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Solution Methods for Nongray Extinction Coefficients

Modest

2013

Radiative Heat Transfer

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Comparison of coupled radiative flow solutions with Project Fire II flight data

Cited by 85 publications

References 9 publications

Transport coefficients and heat fluxes in non-equilibrium high-temperature flows with electronic excitation

Transport coefficients and heat fluxes in non-equilibrium high-temperature flows with electronic excitation

Computational aerothermodynamic design issues for hypersonic vehicles

Solution Methods for Nongray Extinction Coefficients

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