Author: Robert L. McKenzie
Publisher:
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 and Radiative Gain in Expanding Flows of Anharmonic Oscillators
Author: Robert L. McKenzie
Publisher:
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.
Publisher:
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.
NASA Technical Note
NBS Special Publication
Author:
Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 858
Book Description
Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 858
Book Description
Data Index for Energy Transfer Collisions of Atoms and Molecules, 1970-1979
Scientific and Technical Aerospace Reports
Gas Lasers
Author: Masamori Endo
Publisher: CRC Press
ISBN: 1351837192
Category : Technology & Engineering
Languages : en
Pages : 607
Book Description
Lasers with a gaseous active medium offer high flexibility, wide tunability, and advantages in cost, beam quality, and power scalability. Gas lasers have tended to become overshadowed by the recent popularity and proliferation of semiconductor lasers. As a result of this shift in focus, details on modern developments in gas lasers are difficult to find. In addition, different types of gas lasers have unique properties that are not well-described in other references. Collecting expert contributions from authorities dealing with specific types of lasers, Gas Lasers examines the fundamentals, current research, and applications of this important class of laser. It is important to understand all types of lasers, from solid-state to gaseous, before making a decision for any application. This book fills in the gaps by discussing the definition and properties of gaseous media along with its fluid dynamics, electric excitation circuits, and optical resonators. From this foundation, the discussion launches into the basic physics, characteristics, applications, and current research efforts for specific types of gas lasers: CO lasers, CO2 lasers, HF/DF lasers, excimer lasers, iodine lasers, and metal vapor lasers. The final chapter discusses miscellaneous lasers not covered in the previous chapters. Collecting hard-to-find material into a single, convenient source, Gas Lasers offers an encyclopedic survey that helps you approach new applications with a more complete inventory of laser options.
Publisher: CRC Press
ISBN: 1351837192
Category : Technology & Engineering
Languages : en
Pages : 607
Book Description
Lasers with a gaseous active medium offer high flexibility, wide tunability, and advantages in cost, beam quality, and power scalability. Gas lasers have tended to become overshadowed by the recent popularity and proliferation of semiconductor lasers. As a result of this shift in focus, details on modern developments in gas lasers are difficult to find. In addition, different types of gas lasers have unique properties that are not well-described in other references. Collecting expert contributions from authorities dealing with specific types of lasers, Gas Lasers examines the fundamentals, current research, and applications of this important class of laser. It is important to understand all types of lasers, from solid-state to gaseous, before making a decision for any application. This book fills in the gaps by discussing the definition and properties of gaseous media along with its fluid dynamics, electric excitation circuits, and optical resonators. From this foundation, the discussion launches into the basic physics, characteristics, applications, and current research efforts for specific types of gas lasers: CO lasers, CO2 lasers, HF/DF lasers, excimer lasers, iodine lasers, and metal vapor lasers. The final chapter discusses miscellaneous lasers not covered in the previous chapters. Collecting hard-to-find material into a single, convenient source, Gas Lasers offers an encyclopedic survey that helps you approach new applications with a more complete inventory of laser options.
OAR Cumulative Index of Research Results
A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows
Author: Walter Albert Reinhardt
Publisher:
ISBN:
Category : Dissociation
Languages : en
Pages : 340
Book Description
A simplified mathematical model is derived that is useful for studying the effects of vibration-dissociation coupling in fluid flows. The derivation is based on energy-moment procedure for simplifying the master equations. To obtain the model equations it is assumed that the vibrational energy can be approximated by the introduction of two vibrational temperatures. The effects of molecular anharmonicity are also accounted for in an approximate manner. The parameters contained within the equations are evaluated by making comparisons with experimental data. It is shown that the model contains the minimum required structure allowing favorable agreement with existing experimental data. Numerical solutions are given for the quasi-steady zone behind a normal shock wave, for the complete structure of a shock wave, and for nozzle flow. The results provide the appropriate pre-exponential temperature dependence of the effective dissociation rate, yield and induction time before dissociation is observed, and, in the case of expanding flow, yield one-fourth less effective relaxation time than the Landau-Teller theory. The thermodynamic quantities for the vibrational mode (partition function, internal energy, and specific heat) agree accurately with like quantities evaluated from spectroscopic data. By the introduction of appropriate assumptions it is shown that the equations reduce to a form identical to the Marrone-Treanor model except for a "truncation factor". When the vibrational temperatures are not large, the model is identical to that of Landau and Teller. The numerical procedure used to integrate the system of rate and flow equations is also described.
Publisher:
ISBN:
Category : Dissociation
Languages : en
Pages : 340
Book Description
A simplified mathematical model is derived that is useful for studying the effects of vibration-dissociation coupling in fluid flows. The derivation is based on energy-moment procedure for simplifying the master equations. To obtain the model equations it is assumed that the vibrational energy can be approximated by the introduction of two vibrational temperatures. The effects of molecular anharmonicity are also accounted for in an approximate manner. The parameters contained within the equations are evaluated by making comparisons with experimental data. It is shown that the model contains the minimum required structure allowing favorable agreement with existing experimental data. Numerical solutions are given for the quasi-steady zone behind a normal shock wave, for the complete structure of a shock wave, and for nozzle flow. The results provide the appropriate pre-exponential temperature dependence of the effective dissociation rate, yield and induction time before dissociation is observed, and, in the case of expanding flow, yield one-fourth less effective relaxation time than the Landau-Teller theory. The thermodynamic quantities for the vibrational mode (partition function, internal energy, and specific heat) agree accurately with like quantities evaluated from spectroscopic data. By the introduction of appropriate assumptions it is shown that the equations reduce to a form identical to the Marrone-Treanor model except for a "truncation factor". When the vibrational temperatures are not large, the model is identical to that of Landau and Teller. The numerical procedure used to integrate the system of rate and flow equations is also described.
Publications
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1216
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1216
Book Description
Publications of the National Bureau of Standards
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 412
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 412
Book Description