CVCV-model validation by means of radiative heating calculations (Coupled Vibration-Chemistry-Vibration for hypervelocity flow around reentry vehicles)

Knab, O.; Gogel, T.; H-HMesserschmid, Fruehauf

doi:10.2514/6.1995-623

Cited by 3 publications

(2 citation statements)

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“…The one proposed by Candler [32] is inconsistent in the sense that at thermal equilibrium, it differs from zero. Hence, the modified version of Knab et al [33] has been chosen:…”

Section: Vibrational-vibrational Exchangementioning

confidence: 99%

“…At high speeds, it is important to account for the energy lost by the free electrons during ionization of the atoms and molecules, as already stressed in [31][32][33][34][35][36][37]. Otherwise, electron-impact ionization reactions, and in general all the reactions involving free electrons, produce a large number of free electrons without depleting their kinetic energy, thus enhancing their production.…”

Section: Chemistry Electron/electronic Energy Couplingmentioning

confidence: 99%

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Modelling of high-enthalpy, high-Mach number flows

Degrez

Lani

Panesi

et al. 2009

J. Phys. D: Appl. Phys.

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A review is made of the computational models of high-enthalpy flows developed over the past few years at the von Karman Institute and Université Libre de Bruxelles, for the modelling of high-enthalpy hypersonic (re-)entry flows. Both flows in local thermo-chemical equilibrium (LTE) and flows in thermo-chemical non-equilibrium (TCNEQ) are considered. First, the physico-chemical models are described, i.e. the set of conservation laws, the thermodynamics, transport phenomena and chemical kinetics models. Particular attention is given to the correct modelling of elemental (LTE flows) and species (chemical non-equilibrium—CNEQ—flows) transport. The numerical algorithm, based on a state-of-the-art finite volume discretization, is then briefly described. Finally, selected examples are included to illustrate the capabilities of the developed solver.

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“…The one proposed by Candler [32] is inconsistent in the sense that at thermal equilibrium, it differs from zero. Hence, the modified version of Knab et al [33] has been chosen:…”

Section: Vibrational-vibrational Exchangementioning

confidence: 99%

Section: Chemistry Electron/electronic Energy Couplingmentioning

confidence: 99%

Modelling of high-enthalpy, high-Mach number flows

Degrez

Lani

Panesi

et al. 2009

J. Phys. D: Appl. Phys.

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Modeling of sulfur gases and chemiions in aircraft engines

Starik

Савельев

Титова

et al. 2002

Aerospace Science and Technology

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The formation of sulfur-containing gases and chemiions in the combustor and their evolution in the turbine of aircraft-engines between combustor exit and engine exit are computed including the conversion fraction of fuel sulfur into SO 3 and H 2 SO 4. The combustion is approximated by an adiabatic time-dependent box-model. The temperature and pressure evolution in the flow between combustor exit and engine exit is modeled using a quasi one-dimensional (Q1D) model. New kinetic models for S-containing gases and chemiions are used. About 1% of the sulfur molecules are computed to be converted into SO 3 within the combustor and about 10% into SO 3 and H 2 SO 4 before engine exit. Box models agree with the Q1D results for the same initial and thermodynamic conditions, but underestimate sulfur conversion by a factor of 3 if using a linear temperature profile. The number of positive and negative ions formed within the combustor, mainly NO + and HSO − 4 , depends strongly on the fuel/air ratio and on recombination reactions, mainly with C 2 H 3 O + ions. The model computes a total ion emission of 2•10 15 per kg of fuel burned at cruise. Far larger ion concentrations close to values observed behind engines at ground, are computed for higher combustor inlet pressure and higher fuel/air ratio.  2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Zusammenfassung Die Bildung von schwefelhaltigen Gasen und Chemi-Ionen in der Brennkammer von Flugzeugtriebwerken und ihre Veränderung in der Turbine zwischen Brennkammer und Treibwerksaustritt werden berechnet, einschließlich der Umwandlung von Treibstoff-Schwefel in SO 3 und H 2 SO 4. Die Verbrennung wird mit einem adiabatischen instationären Box-Modell approximiert. Das Temperatur-und Druck-Profil entlang der Strömung vom Brennkammer-Austritt bis Triebwerks-Austritt werden mit einem quasi-eindimensionalen (Q1D) Strömungs-Model berechnet. Für die Kinetik der S-haltigen Gase und der Chemi-Ionen werden neue Modelle benutzt. Etwa 1% der Schwefelmoleküle werden in der Brennkammer in SO 3 und etwa 10% in der Turbine in SO 3 und H 2 SO 4 umgewandelt. Für gleiche thermodynamische Bedingungen liefern Box-Modelle gleiche Ergebnisse, unterschätzen aber die Umwandlung um einen Faktor 3, wenn das Temperaturprofil in der Turbine durch ein lineares Profil approximiert wird. Die Zahl der positiven and negativen Ionen, die in der Brennkammer gebildet werden, vorwiegend NO + and HSO − 4 , hängt stark vom Treibstoff/Luft-Verhältnis und den Rekombinations-Reaktionen, vorwiegend mit C 2 H 3 O + Ionen, ab. Im Modell werden insgesamt 2•10 15 Ionen pro kg verbrannten Treibstoffs unter Reiseflugbedingengen emittiert. Sehr viel größere Konzentrationen, wie am Boden hinter Triebwerken gemessen, werden für höhere Brennkammerdrücke und Brennstoff/Luft-Verhältnisse berechnet.  2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.

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Kinetic mechanisms for the initiation of supersonic combustion of a hydrogen-air mixture behind a shock wave under the excitation of molecular vibrations in initial reagents

Starik

Титова

2001

Tech. Phys.

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CVCV-model validation by means of radiative heating calculations (Coupled Vibration-Chemistry-Vibration for hypervelocity flow around reentry vehicles)

Cited by 3 publications

References 0 publications

Modelling of high-enthalpy, high-Mach number flows

Modelling of high-enthalpy, high-Mach number flows

Modeling of sulfur gases and chemiions in aircraft engines

Kinetic mechanisms for the initiation of supersonic combustion of a hydrogen-air mixture behind a shock wave under the excitation of molecular vibrations in initial reagents

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