A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows

A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows PDF Author: Walter Albert Reinhardt
Publisher:
ISBN:
Category : Dissociation
Languages : en
Pages : 340

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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.

A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows

A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows PDF Author: Walter Albert Reinhardt
Publisher:
ISBN:
Category : Dissociation
Languages : en
Pages : 340

Get Book Here

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.

Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :

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A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows

A Simplified Molecular Model for Studying Vibration-dissociation Coupling in Fluid Flows PDF Author: Walter Albert Reinhardt
Publisher:
ISBN:
Category : Dissociation
Languages : en
Pages : 338

Get Book Here

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.

National Union Catalog

National Union Catalog PDF Author:
Publisher:
ISBN:
Category : Union catalogs
Languages : en
Pages : 964

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Includes entries for maps and atlases.

The National Union Catalogs, 1963-

The National Union Catalogs, 1963- PDF Author:
Publisher:
ISBN:
Category : American literature
Languages : en
Pages : 760

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Conservation Equations and Physical Models for Hypersonic Air Flows in Thermal and Chemical Nonequilibrium

Conservation Equations and Physical Models for Hypersonic Air Flows in Thermal and Chemical Nonequilibrium PDF Author: Peter A. Gnoffo
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 68

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Nonequilibrium Gas Dynamics and Molecular Simulation

Nonequilibrium Gas Dynamics and Molecular Simulation PDF Author: Iain D. Boyd
Publisher: Cambridge University Press
ISBN: 1107073448
Category : Science
Languages : en
Pages : 383

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Book Description
7.1 Introduction -- 7.2 Rotational Energy Exchange Models -- 7.2.1 Constant Collision Number -- 7.2.2 The Parker Model -- 7.2.3 Variable Probability Exchange Model of Boyd -- 7.2.4 Nonequilibrium Direction Dependent Model -- 7.2.5 Model Results -- 7.3 Vibrational Energy Exchange Models -- 7.3.1 Constant Collision Number -- 7.3.2 The Millikan-White Model -- 7.3.3 Quantized Treatment for Vibration -- 7.3.4 Model Results -- 7.4 Dissociation Chemical Reactions -- 7.4.1 Total Collision Energy Model -- 7.4.2 Redistribution of Energy Following a Dissociation Reaction -- 7.4.3 Vibrationally Favored Dissociation Model -- 7.5 General Chemical Reactions -- 7.5.1 Reaction Rates and Equilibrium Constant -- 7.5.2 Backward Reaction Rates in DSMC -- 7.5.3 Three-Body Recombination Reactions -- 7.5.4 Post-Reaction Energy Redistribution and General Implementation -- 7.5.5 DSMC Solutions for Reacting Flows -- 7.6 Summary -- Appendix A: Generating Particle Properties -- Appendix B: Collisional Quantities -- Appendix C: Determining Post-Collision Velocities -- Appendix D: Macroscopic Properties -- Appendix E: Common Integrals -- References -- Index

Numerical Simulation of Chemically Reactive Hypersonic Flows

Numerical Simulation of Chemically Reactive Hypersonic Flows PDF Author: Sanjeev Kumar
Publisher:
ISBN: 9783832250652
Category :
Languages : en
Pages : 131

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Thermodynamic Properties of Gaseous Nitrogen

Thermodynamic Properties of Gaseous Nitrogen PDF Author: Harold William Woolley
Publisher:
ISBN:
Category : Density
Languages : en
Pages : 128

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Book Description
The tables of thermal properties of molecular nitrogen that have been prepared in an NBS-NACA series have been grouped together herein for convenient use. They include the thermodynamic functions for the gas, both real and ideal, the transport properties for a gas, and the vapor pressure of the liquid and the solid. A table of ideal-gas properties is presented, including the specific heat at constant pressure, enthalpy, entropy, and the free-energy function; and a table giving these same properties for atomic nitrogen is also included. The tables of the real-gas thermodynamic properties include density, compressibility factor, entropy, enthalpy, specific heat at constant presssure, ratio of specific heats, and velocity of sound at very low frequency.

Light Harvesting in Photosynthesis

Light Harvesting in Photosynthesis PDF Author: Roberta Croce
Publisher: CRC Press
ISBN: 1351242873
Category : Science
Languages : en
Pages : 778

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Book Description
This landmark collective work introduces the physical, chemical, and biological principles underlying photosynthesis: light absorption, excitation energy transfer, and charge separation. It begins with an introduction to properties of various pigments, and the pigment proteins in plant, algae, and bacterial systems. It addresses the underlying physics of light harvesting and key spectroscopic methods, including data analysis. It discusses assembly of the natural system, its energy transfer properties, and regulatory mechanisms. It also addresses light-harvesting in artificial systems and the impact of photosynthesis on our environment. The chapter authors are amongst the field’s world recognized experts. Chapters are divided into five main parts, the first focused on pigments, their properties and biosynthesis, and the second section looking at photosynthetic proteins, including light harvesting in higher plants, algae, cyanobacteria, and green bacteria. The third part turns to energy transfer and electron transport, discussing modeling approaches, quantum aspects, photoinduced electron transfer, and redox potential modulation, followed by a section on experimental spectroscopy in light harvesting research. The concluding final section includes chapters on artificial photosynthesis, with topics such as use of cyanobacteria and algae for sustainable energy production. Robert Croce is Head of the Biophysics Group and full professor in biophysics of photosynthesis/energy at Vrije Universiteit, Amsterdam. Rienk van Grondelle is full professor at Vrije Universiteit, Amsterdam. Herbert van Amerongen is full professor of biophysics in the Department of Agrotechnology and Food Sciences at Wageningen University, where he is also director of the MicroSpectroscopy Research Facility. Ivo van Stokkum is associate professor in the Department of Physics and Astronomy, Faculty of Sciences, at Vrije Universiteit, Amsterdam.