Computer Program for One-dimensional Nonequilibrium Reacting Gas Flow

Computer Program for One-dimensional Nonequilibrium Reacting Gas Flow PDF Author: H. S. Dresser
Publisher:
ISBN:
Category : Aerothermodynamics
Languages : en
Pages : 256

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Book Description
A computer program has been developed for one-dimensional nonequilibrium reacting gas flow. The program is written in Fortran IV and is compatible with the IBM 7044/7094 direct coupled digital computer system at Wright-Patterson Air Force Base, Ohio. In addition to nonequilibrium chemistry, the program includes nonequilibrium vibrational and electronic energy relaxation and coupling effects between these energy modes and the chemistry. The formulation is based on a one-dimensional flow matching either a prescribed pressure or area variation along a streamtube. Thermodynamic properties are computed by assuming an ideal gas mixture and the equilibration of translational and rotational temperatures. The internal energy modes, rotation, vibration, and electronic excitation, are considered uncoupled; and a rigid rotator, cut off simple harmonic oscillator, independent of the electronic state, is assumed. Excitation of vibrational and electronic energies are treated similarly with terms which account for relaxation and chemical reactions. The effects of nonequilibrium vibrational and electronic states on chemical rates are included in the coupling analysis. The vibrational relaxation time constants were obtained from the Millikan and White data while the electronic relaxation time constants were determined for nitrogen from an analysis of existing shock tube radiation measurements. The computer program was used to solve for the nonequilibrium flow in a hypersonic nozzle and for eight streamlines in the inviscid flow field over a spherically blunted nine-degree semiapex angle cone at zero angle of attack. (Author).

Computer Program for One-dimensional Nonequilibrium Reacting Gas Flow

Computer Program for One-dimensional Nonequilibrium Reacting Gas Flow PDF Author: H. S. Dresser
Publisher:
ISBN:
Category : Aerothermodynamics
Languages : en
Pages : 256

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Book Description
A computer program has been developed for one-dimensional nonequilibrium reacting gas flow. The program is written in Fortran IV and is compatible with the IBM 7044/7094 direct coupled digital computer system at Wright-Patterson Air Force Base, Ohio. In addition to nonequilibrium chemistry, the program includes nonequilibrium vibrational and electronic energy relaxation and coupling effects between these energy modes and the chemistry. The formulation is based on a one-dimensional flow matching either a prescribed pressure or area variation along a streamtube. Thermodynamic properties are computed by assuming an ideal gas mixture and the equilibration of translational and rotational temperatures. The internal energy modes, rotation, vibration, and electronic excitation, are considered uncoupled; and a rigid rotator, cut off simple harmonic oscillator, independent of the electronic state, is assumed. Excitation of vibrational and electronic energies are treated similarly with terms which account for relaxation and chemical reactions. The effects of nonequilibrium vibrational and electronic states on chemical rates are included in the coupling analysis. The vibrational relaxation time constants were obtained from the Millikan and White data while the electronic relaxation time constants were determined for nitrogen from an analysis of existing shock tube radiation measurements. The computer program was used to solve for the nonequilibrium flow in a hypersonic nozzle and for eight streamlines in the inviscid flow field over a spherically blunted nine-degree semiapex angle cone at zero angle of attack. (Author).

Method for Calculation of the One-dimensional Nonequilibrium Flow of a General Gas Mixture Through a Hypersonic Nozzle

Method for Calculation of the One-dimensional Nonequilibrium Flow of a General Gas Mixture Through a Hypersonic Nozzle PDF Author: George Emanuel
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 112

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Book Description
The work described is a continuation of that reported previously in AEDC-TN-61-65 (calculation of the one-dimensional nonequilibrium flow of air through a hypersonic nozzle). In particular, a method is presented for the exact numerical calculation of the one-dimensional nonequilibrium flow of a general gas mixture through a converging-diverging nozzle. General equations are given for a mixture of perfect gases with an arbitrary number of species undergoing an arbitrary number of chemical and vibrational rate processes. An inexact but accurate method, similar in form to the method employed in the nonequilibrium case, is also given for calculating the corresponding one-dimensional equilibrium flow. The numerical method of solution applicable to both cases is described, including a simple procedure for starting the nonequilibrium calculations from an equilibrium condition and an improved method for controlling integration step size. The factors that affect over-all computation time are discussed. A computer program for an IBM 7090 has been written for the general gas mixture. Specific calculations are reported for a model of air consisting of O, N, NO, N2, and O2 and including eight chemical reactions plus the vibrational processes of the three diatomic species.

Computer Program for the Numerical Solution of Nonequilibrium Expansions of Reacting Gas Mixtures

Computer Program for the Numerical Solution of Nonequilibrium Expansions of Reacting Gas Mixtures PDF Author: J. A. Lordi
Publisher:
ISBN:
Category : Gas dynamics
Languages : en
Pages : 164

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Computer Program Abstracts

Computer Program Abstracts PDF Author:
Publisher:
ISBN:
Category : Computer programs
Languages : en
Pages : 650

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 964

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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 : 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.

General Chemical Kinetics Computer Program for Static and Flow Reactions, with Application to Combustion and Shock-tube Kinetics

General Chemical Kinetics Computer Program for Static and Flow Reactions, with Application to Combustion and Shock-tube Kinetics PDF Author: David A. Bittker
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 216

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Book Description
A general chemical kinetics program is described for complex, homogeneous ideal-gas reactions in any chemical system. Its main features are flexibility and convenience in treating many different reaction conditions. The program solves numerically the differential equations describing complex reaction in either a static system or one-dimensional inviscid flow. Applications include ignition and combustion, shock wave reactions, and general reactions in a flowing or static system. An implicit numerical solution method is used which works efficiently for the extreme conditions of a very slow or a very fast reaction. The theory is described, and the computer program and users' manual are included.

A Selected Listing of NASA Scientific and Technical Reports

A Selected Listing of NASA Scientific and Technical Reports PDF Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 436

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Technical Abstract Bulletin

Technical Abstract Bulletin PDF Author: Defense Documentation Center (U.S.)
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 784

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NASA Scientific and Technical Reports

NASA Scientific and Technical Reports PDF Author: United States. National Aeronautics and Space Administration Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 472

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