Effect of molecular diameters on state-to-state transport properties: The shear viscosity coefficient

Кустова, Е. В.; Kremer, Gilberto M.

doi:10.1016/j.cplett.2015.07.012

Cited by 15 publications

(3 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Calculating transport properties as solutions to linear transport systems derived from a Chapman-Enskog method applied to the Boltzmann equation can be expensive for state-to-state models due to the large number of pseudospecies in the mixture. These properties are based on transport collision integrals that depend on the degree of internal excitation of the molecules [66,67]. In this work, we use the transport collision integrals of the ground rovibronic state of the nitrogen molecule [68], neglecting how these data are affected by internal energy excitation.…”

Section: Appendix: Transport Properties Linear Systemsmentioning

confidence: 99%

Energy Accommodation Coefficient Calculation Methodology Using State-to-State Catalysis Applied to Hypersonic Flows

2020

View full text Add to dashboard Cite

The interplay of a gas-surface interaction and thermal nonequilibrium is still an open problem in aerothermodynamics. In the case of reusable thermal protection systems, it is unclear how much of the recombination energy is stored internally in the molecules produced by surface catalytic reactions, potentially leading to nonequilibrium between their translational and internal energy modes. A methodology is developed to calculate the energy accommodation coefficient using a rovibrational state-to-state chemical mechanism for a nitrogen mixture coupled with a generalized form of the catalytic recombination coefficient. The flow around a spherical body is simulated in hypersonic conditions, allowing study of the amount of energy deposited on the surface and stored in the recombining molecules. Internal energy quenching into translational energy is found, which is a phenomenon also observed experimentally, keeping the total energy transferred to the surface overall constant. The methodology developed for the application of a state-to-state model in the computational fluid dynamics framework coupled with catalysis is generic and applicable to a variety of other similar mechanisms.

show abstract

Section: Appendix: Transport Properties Linear Systemsmentioning

confidence: 99%

Energy Accommodation Coefficient Calculation Methodology Using State-to-State Catalysis Applied to Hypersonic Flows

2020

View full text Add to dashboard Cite

show abstract

“…In the past, a few studies focused on the estimation of transport properties of vibrationally and rotationally excited molecules [32,33,62]. However, in these studies only influence of molecule vibrations on the collision diameter was taken into account.…”

Section: Transport Propertiesmentioning

confidence: 99%

Influence of vibrations and rotations of diatomic molecules on their physical properties: II. Refractive index, reactivity and diffusion coefficients

Sharipov¹,

Loukhovitski²,

Starik³

2016

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

The influence of the excitation of vibrational and rotational states of diatomic molecules (H 2 , N 2 , O 2 , NO, OH, CO, CH, HF and HCl) on refractive index, reactivity and transport coefficients was analyzed by using ab initio calculated data on the effective state-specific dipole moment and static polarizability obtained in the preceding paper of the present series. It has been revealed that, for non-polar molecules, the excitation both of vibrational and rotational degrees of freedom increases the averaged polarizability and, as a consequence, the refractive index. Meanwhile, for polar molecules, the effect of molecule excitation is more complex: it can either increase or decrease the refractive index. It was also shown that the excitation of molecules slightly influences the rate constants of barrierless chemical reactions between neutral particles; whereas, for ion-molecule reactions, this effect can be more pronounced. Analysis of the variation of diffusion coefficients, taking into account the effect of molecule excitation both on the collision diameter and on the well depth of intermolecular potential, exhibited that, for non-polar molecules, the effect associated with the change of collision diameter prevails. However, for polar molecules, the effect of the excitation of vibrational states on the well depth of intermolecular potential can compensate or even exceed the decrease of diffusion coefficient due to the averaged collision diameter rise.

show abstract

“…The collision diameter σ ij that specifies the range of repulsive valence forces in the Lennard-Jones potential for a pair of colliding molecules of i and j types is an essential parameter commonly used for estimating the gas-kinetic collision frequency, transport properties (diffusion, viscosity, and thermal conductivity coefficients), the characteristic time of vibrational and rotational relaxation, and so forth. − The σ ij values can be directly obtained from molecular beam scattering experiments or derived from the measurements of such macroscopic parameters as second virial, viscosity, and diffusion coefficients. ,, However, owing to the difficulties in carrying out appropriate experiments (especially, for transient species and radicals), theoretical determination of the collision diameters is immensely important for predictive modeling of chemically reacting flows. ,,− …”

Section: Introductionmentioning

confidence: 99%

Molecular Collision Diameters and Electronic Polarizabilities: Inherent Relationship and Fast Evaluation

Loukhovitski

Sharipov

2021

J. Phys. Chem. A

View full text Add to dashboard Cite

The collision diameter σ for a large set of molecular species is related to the static electronic polarizability αel. A remarkable correlation between these quantities conceptually similar to the analogous one previously identified for atoms is revealed. Our recommended model is the function σ(αel) = p 1 + p 2αel 1/3, where p 1 = 0.768 Å and p 2 = 2.168 are the fitting parameters providing the best overall match to the reference data for collision diameter (181 data points). The obtained correlation allows one to easily find the collision diameter of molecules from the known polarizability and vice versa. These findings can be useful for many applications, where there is a need for inexpensive assessments of the collision diameters or electronic polarizabilities, for example, when developing the transport property databases for modeling of chemically reacting flows.

show abstract

Effect of molecular diameters on state-to-state transport properties: The shear viscosity coefficient

Cited by 15 publications

References 25 publications

Energy Accommodation Coefficient Calculation Methodology Using State-to-State Catalysis Applied to Hypersonic Flows

Energy Accommodation Coefficient Calculation Methodology Using State-to-State Catalysis Applied to Hypersonic Flows

Influence of vibrations and rotations of diatomic molecules on their physical properties: II. Refractive index, reactivity and diffusion coefficients

Molecular Collision Diameters and Electronic Polarizabilities: Inherent Relationship and Fast Evaluation

Contact Info

Product

Resources

About