A non-equilibrium dissociation and vibrational relaxation model for computational fluid dynamics simulations of flows with shock waves

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A non-equilibrium dissociation and vibrational relaxation model for computational fluid dynamics simulations of flows with shock waves. / Gorbachev, Yuriy; Kunova, Olga; Shoev, Georgy.

In: Physics of Fluids, Vol. 33, No. 12, 126105, 12.2021.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{1f3d70fb951540649f7affdcde46c2f9,

title = "A non-equilibrium dissociation and vibrational relaxation model for computational fluid dynamics simulations of flows with shock waves",

abstract = "Gasdynamic equations describing a vibrationally non-equilibrium flow of a chemically reacting binary mixture A 2 / A are derived within the previously proposed general approach of solving the Boltzmann equation. The obtained equations differ from the traditional ones in their expressions for the reaction and relaxation rates. Aiming to obtain analytical expressions for these rates, a cutoff harmonic oscillator model for the vibrational spectrum of A2 molecules and dissociation from the highest vibrational level are assumed. The equation for the dissociation rate describes two different dissociation regimes, determined by the dissociation rate constant at {"}low{"}temperatures and by the vibrational energy exchange rate constants at {"}high{"}temperatures, since it is limited by the vibrational energy delivery to the highest vibrational levels. A parameter for determining the appropriate regime is proposed. The derived expressions for the reaction and relaxation rates are used in computations of O2/O and N2/N mixture flows. A comparison of our results with the numerical and experimental data of other authors shows that the model used for the reaction and relaxation rates calculation should be refined, at least by considering anharmonicity effects.",

keywords = "EQUATIONS, INHOMOGENEOUS GAS-MIXTURES, INTERNAL DEGREES, RATE COEFFICIENTS, RATES",

author = "Yuriy Gorbachev and Olga Kunova and Georgy Shoev",

note = "Publisher Copyright: {\textcopyright} 2021 Author(s).",

year = "2021",

month = dec,

doi = "10.1063/5.0062628",

language = "English",

volume = "33",

journal = "Physics of Fluids",

issn = "1070-6631",

publisher = "American Institute of Physics",

number = "12",

}

RIS

TY - JOUR

T1 - A non-equilibrium dissociation and vibrational relaxation model for computational fluid dynamics simulations of flows with shock waves

AU - Gorbachev, Yuriy

AU - Kunova, Olga

AU - Shoev, Georgy

PY - 2021/12

Y1 - 2021/12

N2 - Gasdynamic equations describing a vibrationally non-equilibrium flow of a chemically reacting binary mixture A 2 / A are derived within the previously proposed general approach of solving the Boltzmann equation. The obtained equations differ from the traditional ones in their expressions for the reaction and relaxation rates. Aiming to obtain analytical expressions for these rates, a cutoff harmonic oscillator model for the vibrational spectrum of A2 molecules and dissociation from the highest vibrational level are assumed. The equation for the dissociation rate describes two different dissociation regimes, determined by the dissociation rate constant at "low"temperatures and by the vibrational energy exchange rate constants at "high"temperatures, since it is limited by the vibrational energy delivery to the highest vibrational levels. A parameter for determining the appropriate regime is proposed. The derived expressions for the reaction and relaxation rates are used in computations of O2/O and N2/N mixture flows. A comparison of our results with the numerical and experimental data of other authors shows that the model used for the reaction and relaxation rates calculation should be refined, at least by considering anharmonicity effects.

AB - Gasdynamic equations describing a vibrationally non-equilibrium flow of a chemically reacting binary mixture A 2 / A are derived within the previously proposed general approach of solving the Boltzmann equation. The obtained equations differ from the traditional ones in their expressions for the reaction and relaxation rates. Aiming to obtain analytical expressions for these rates, a cutoff harmonic oscillator model for the vibrational spectrum of A2 molecules and dissociation from the highest vibrational level are assumed. The equation for the dissociation rate describes two different dissociation regimes, determined by the dissociation rate constant at "low"temperatures and by the vibrational energy exchange rate constants at "high"temperatures, since it is limited by the vibrational energy delivery to the highest vibrational levels. A parameter for determining the appropriate regime is proposed. The derived expressions for the reaction and relaxation rates are used in computations of O2/O and N2/N mixture flows. A comparison of our results with the numerical and experimental data of other authors shows that the model used for the reaction and relaxation rates calculation should be refined, at least by considering anharmonicity effects.

KW - EQUATIONS

KW - INHOMOGENEOUS GAS-MIXTURES

KW - INTERNAL DEGREES

KW - RATE COEFFICIENTS

KW - RATES

UR - http://www.scopus.com/inward/record.url?scp=85120753564&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/88d45086-ab57-3ca1-bfc2-b44ce2392c22/

U2 - 10.1063/5.0062628

DO - 10.1063/5.0062628

M3 - Article

VL - 33

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 12

M1 - 126105

ER -

ID: 88346157