Author: Francis Hugh MailliePublisher:
ISBN:
Category : Relaxation (Gas dynamics)
Languages : en
Pages : 282
Book Description
Vibrational Relaxation of Anharmonic Oscillators with Vibration-vibration and Vibration-translation Energy Exchange
Author: Francis Hugh MailliePublisher:
ISBN:
Category : Relaxation (Gas dynamics)
Languages : en
Pages : 282
Book Description
Vibrational Relaxation of Anharmonic Oscillators
Author: J. W. RichPublisher:
ISBN:
Category : Oscillators, Transistor
Languages : en
Pages : 102
Book Description
The terms in the master equation for vibrational relaxation of anharmonic oscillators are ordered according to the rates of the relaxation processes (vibrational exchange, vibrational-energy transfer to translation). A perturbation procedure is developed by making use of the fact that the vibration-translation energy exchange transitions are much slower than the vibration-vibration transitions. The population distributions in the master equation are expanded about their values when the vibration-vibration mechanism is the only one present. To zeroth order, the master equation is satisfied by a distribution derived previously by Treanor for anharmonic oscillators. This distribution is maintained by vibration-vibration exchange, and is only Boltzmann during relaxation in the limit of vanishing anharmonicity. The perturbation on this distribution, created by vibration energy transfer to translation, is calculated to first order for a special case. The relaxation of the first moment of the zeroth-order distribution function is also investigated. The population of the lowest vibrational states can be considerably lower than the population predicted by the Landau-Teller model for the relaxation process. Furthermore, since the inversion tends to weight those states having fast vibration-to-translation energy transfer rates, the overall energy relaxation rate can be accelerated. (Author).
Vibrational Relaxation and Radiative Gain in Expanding Flows of Anharmonic Oscillators
Author: Robert L. McKenziePublisher:
ISBN:
Category : Gas dynamics
Languages : en
Pages : 36
Book Description
The set of master rate equations for the vibrational relaxation of mixtures of anharmonic diatomic gases in supersonic nozzle expansions is integrated numerically. Large deviations from a Boltzmann distribution of vibrational state population are predicted, particularly when vibrational energy is exchanged between two near-resonant diatomic species. Radiative gain coefficients for nonequilibrium vibration-rotation transitions are also computed and positive gains, sufficient to support laser oscillations, are predicted for CO-N2 and CO-N,-Ar admixtures.
Vibrational Relaxation of Anharmonic Oscillator Molecules
Author: Kenneth N. C. BrayPublisher:
ISBN:
Category : Molecular dynamics
Languages : en
Pages : 68
Book Description
The vibrational relaxation of a system of anharmonic oscillator molecules was analysed, by a moment method. Exchange of vibrational energy between molecules was included, and plays an important part in the relaxation mechanism. Calculations for nitrogen show that, during vibrational excitation, the relaxation rate is only slightly different from that predicted by Landau and Teller, for harmonic oscillator molecules. However, very rapid vibrational de-excitation is found to occur, under conditions far from equilibrium. This is a result of a build-up of upper level vibrational populations, fed by rapid vibration-vibration exchanges. (Author).
Vibration-translation Energy Transfer in Anharmonic Diatomic Molecules. 2: The Vibrational Quantum Number Dependence
Author: Relaxation by Vibration-vibration Exchange Processes
Author: Edward R. FisherPublisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
A comparative study is presented on the relaxation of harmonic and anharmonic oscillators through vibration-vibration exchange processes. The harmonic model is concluded to be inadequate to describe vibration-vibration exchange since the small anharmonicity associated with real molecules has profound effects on both the dynamic behavior and the steady state distributions resulting in the relaxation of initially non-equilibrium vibrational distributions. (Author).
Vibrational Relaxation and Radiative Gain in Expanding Flows of Anharmonic Oscillators
Author: Robert L. McKenziePublisher:
ISBN:
Category : Gas dynamics
Languages : en
Pages : 24
Book Description
The set of master rate equations for the vibrational relaxation of mixtures of anharmonic diatomic gases in supersonic nozzle expansions is integrated numerically. Large deviations from a Boltzmann distribution of vibrational state population are predicted, particularly when vibrational energy is exchanged between two near-resonant diatomic species. Radiative gain coefficients for nonequilibrium vibration-rotation transitions are also computed and positive gains, sufficient to support laser oscillations, are predicted for CO-N2 and CO-N, -Ar admixtures.
Molecular Vibrational Energy Distributions During Exchange-dominated Relaxation
Author: Charles E. TreanorPublisher:
ISBN:
Category : Gas dynamics
Languages : en
Pages : 46
Book Description
Vibrational Relaxation of Anharmonic Oscillators
Author: Anthony A. BoiarskiPublisher:
ISBN:
Category : Vibration
Languages : en
Pages : 274
Book Description
NBS Special Publication
Author: Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 362
Book Description