O–O2 state-to-state vibrational relaxation and dissociation rates based on quasiclassical calculations

Esposito, Fabrizio; Armenise, I.; Capitta, Giulia; Capitelli, M.

doi:10.1016/j.chemphys.2008.04.004

Cited by 167 publications

(112 citation statements)

References 19 publications

Supporting

Mentioning

101

Contrasting

Unclassified

Order By: Relevance

“…From a theoretical point of view, for an E-R reaction, the reactive cross section ( σ E−R ) is usually defined as (13) where b is the impact parameter, P(b,ϕ ) is the opacity function and ϕ is the orientation angle of the impinging particle. Such expression becomes simpler in the case of axial symmetry, (14) though, due to the usual cell symmetries of the solid surface, it is possible that P depends on the angle. At the same time, in order to sample correctly the impact parameter b ( b = 0 for the initial position of A ad on the cell), according to the standard Monte Carlo method its value should be taken from a b 2 uniform distribution between 0 and b max 2 .…”

Section: Atoms Recombination On a Surfacementioning

confidence: 99%

See 1 more Smart Citation

Molecular Physics of Elementary Processes Relevant to Hypersonics: Atom-Molecule, Molecule-Molecule and Atoms-Surface Processes

Laganá¹,

Lombardi²,

Pirani³

et al. 2014

TOPPJ

View full text Add to dashboard Cite

Abstract:In the present chapter some prototype gas and gas-surface processes occurring within the hypersonic flow layer surrounding spacecrafts at planetary entry are discussed. The discussion is based on microscopic dynamical calculations of the detailed cross sections and rate coefficients performed using classical mechanics treatments for atoms, molecules and surfaces. Such treatment allows the evaluation of the efficiency of thermal processes (both at equilibrium and non equilibrium distributions) based on state-to-state and state specific calculations properly averaged over the population of the initial states. The dependence of the efficiency of the considered processes on the initial partitioning of energy among the various degrees of freedom is discussed.

show abstract

Section: Atoms Recombination On a Surfacementioning

confidence: 99%

“…Similar calculations have been performed also for hydrogen and oxygen systems [10][11][12][13][14]. As to gas surface processes, because of the fact that the characteristics of the actually used TPS materials are usually undisclosed, modeling has been performed on simpler materials like α -and β -quartz or β -cristobalite.…”

Section: Introductionmentioning

confidence: 99%

Molecular Physics of Elementary Processes Relevant to Hypersonics: Atom-Molecule, Molecule-Molecule and Atoms-Surface Processes

Laganá¹,

Lombardi²,

Pirani³

et al. 2014

TOPPJ

View full text Add to dashboard Cite

show abstract

“…Elementary processes (2) correspond to vibration-translation (when P ≡ N 2 , O 2 , N or O) and vibration-vibration (when P ≡ N 2 or O 2 ) processes. Multiquanta jumps are taken into account only when P ≡ N or O; for molecule-induced collisions, the rate coefficients for Δv = ±1 transitions are indeed largely higher [2,26,27,36]. …”

Section: Global Rate Coefficients For N 2 and O 2 Dissociation And Rementioning

confidence: 99%

“…The vibrational energy diagram of the molecules is taken from [26] and [35]. The cases P ≡ N 2 or N for the dissociation of N 2 and P ≡ O 2 or O for the dissociation of O 2 are treated.…”

Section: Global Rate Coefficients For N 2 and O 2 Dissociation And Rementioning

confidence: 99%

“…These assumptions are based on the general hierarchy of relaxation times for the different processes. It is interesting to note that recently, significant efforts have been done by different research groups at NASA Ames [22,23], University of Barcelona [24] and Plasma Institute in Bari [25][26][27] to calculate rovibrational rate coefficients for processes of importance for re-entry applications. In these new databases, the importance of multi-quantum VT and dissociation/recombination processes has been clearly put forward.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Bourdon¹,

Annaloro²,

Bultel³

et al. 2014

TOPPJ

View full text Add to dashboard Cite

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.

show abstract

Molecular Dynamics for State‐to‐State Kinetics of Non‐Equilibrium Molecular Plasmas: State of Art and Perspectives

Capitelli

Celiberto

Esposito

et al. 2009

Plasma Processes & Polymers

Self Cite

View full text Add to dashboard Cite

The theoretical prediction of molecular plasma features in non‐equilibrium conditions relys on the knowledge of the microscopic collisional dynamics. The state‐to‐state kinetic approach in fact requires complete sets of cross‐sections for the main reaction channels, including their dependence on the internal degrees of freedom. In this paper, the main three classes (electron–molecule, atom–molecule, and gas–surface interaction) of elementary processes have been considered, reviewing old and recent results for hydrogen, oxygen, and nitrogen molecular plasmas. Within each class selected processes have been discussed, summarizing the evidences of theoretical investigation and validating different methods by comparison with available experiments. Future achievements are outlined moving to polyatomic systems, of great interest in many technological plasma‐chemical systems.

show abstract

O–O2 state-to-state vibrational relaxation and dissociation rates based on quasiclassical calculations

Cited by 167 publications

References 19 publications

Molecular Physics of Elementary Processes Relevant to Hypersonics: Atom-Molecule, Molecule-Molecule and Atoms-Surface Processes

Molecular Physics of Elementary Processes Relevant to Hypersonics: Atom-Molecule, Molecule-Molecule and Atoms-Surface Processes

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

Molecular Dynamics for State‐to‐State Kinetics of Non‐Equilibrium Molecular Plasmas: State of Art and Perspectives

Contact Info

Product

Resources

About