Nonequilibrium Blunt Body Flow of Air at Low Reynolds Number
Nonequilibrium Blunt Body Flow of Air at Low Reynolds Number

Author: Arnold J. Galloway

Publisher:

Published: 1972

Total Pages: 132

ISBN-13:

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The report treats the nonequilibrium air flow around blunt bodies at high altitudes and reentry conditions. The inverse method is employed, and a reduced form of the Navier-Stokes equations is solved by finite difference techniques. Solutions are obtained for the flow around bodies which generate spherical, parabolic, and hyperbolic shock shapes. Body shapes closely resembling spherically blunted cones are obtained. The present solutions are compared with a very limited data base and other calculations. The results are shown to agree reasonably well with the data and the independent calculations.

Nonequilibrium Inviscid Flow about Blunt Bodies
Nonequilibrium Inviscid Flow about Blunt Bodies

Author:

Publisher:

Published: 1964

Total Pages: 0

ISBN-13:

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An inverse method was used for analyzing the chemically nonequilibrium flow about a blunt body. This method starts with an assumed form of shock shape. The flow field and the thermodynamics behind the shock is determined by a finite difference mesh scheme. The calculation is continued until the sonic point on the body is exceeded. Mass flow rate is integrated along the curvilinear coordinate normal to the shock to determine locations and shapes of the body and the streamlines. The analysis assumes air to be a five-component reacting gas undergoing six coupled reactions with negligible ionization. Complete rate equations including three-body recombinations are used. Numerical examples are given for frozen and nonequilibrium air flows. Three different kinetic models are used for the reacting cases. The results show that even though the pressure and velocities in the shock layer are not sensitive to the air kinetics, the other thermodynamic properties are significantly influenced by the kinetic models chosen. The nitric oxide concentration is greatly enhanced by its direct formation from molecular oxygen and nitrogen. The extra amount of nitric oxide may cause an appreciable increase in gas cap radiation at high altitudes and superorbital velocities. (Author).

Viscous Nonequilibrium Blunt Body Flows
Viscous Nonequilibrium Blunt Body Flows

Author: William C. L. Shih

Publisher:

Published: 1964

Total Pages: 102

ISBN-13:

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A method is developed which effectively reduces the partial differential equations governing the continuum viscous thin shock layer region (including chemical nonequilibrium effects) about a sphere to a set of total differential equations along radial lines across the shock layer. It is applied to regions downstream of the stagnation point. A systematic procedure is presented to obtain higher approximations in order that accuracy and consistency of the approximations made may be ascertained. Depending upon the degree of the approximation the flow field may be determined along either one or more lines with coupling between the lines. Sample calculations for frozen, equilibrium and nonequilibrium cases are included and comparison made with the stagnation point work of Cheng, Chung, Ho and Probstein and experiments of Ferri et al. Heat transfer and shear parameters are in reasonable agreement. Comparison of shock shapes and downstream variation of other flow quantities were not possible since most of the existing works are valid only near the stagnation point. (Author).

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1972

Total Pages: 958

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Nonequilibrium Inviscid Flow about Blunt Bodies
Nonequilibrium Inviscid Flow about Blunt Bodies

Author:

Publisher:

Published: 1964

Total Pages: 0

ISBN-13:

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An inverse method was used for analyzing the chemically nonequilibrium flow about a blunt body. This method starts with an assumed form of shock shape. The flow field and the thermodynamics behind the shock is determined by a finite difference mesh scheme. The calculation is continued until the sonic point on the body is exceeded. Mass flow rate is integrated along the curvilinear coordinate normal to the shock to determine locations and shapes of the body and the streamlines. The analysis assumes air to be a five-component reacting gas undergoing six coupled reactions with negligible ionization. Complete rate equations including three-body recombinations are used. Numerical examples are given for frozen and nonequilibrium air flows. Three different kinetic models are used for the reacting cases. The results show that even though the pressure and velocities in the shock layer are not sensitive to the air kinetics, the other thermodynamic properties are significantly influenced by the kinetic models chosen. The nitric oxide concentration is greatly enhanced by its direct formation from molecular oxygen and nitrogen. The extra amount of nitric oxide may cause an appreciable increase in gas cap radiation at high altitudes and superorbital velocities. (Author).

Theoretical Modelling of Aeroheating on Sharpened Noses Under Rarefied Gas Effects and Nonequilibrium Real Gas Effects
Theoretical Modelling of Aeroheating on Sharpened Noses Under Rarefied Gas Effects and Nonequilibrium Real Gas Effects

Author: Zhi-Hui Wang

Publisher: Springer

Published: 2014-08-28

Total Pages: 107

ISBN-13: 3662443651

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Theoretical Modelling of Aeroheating on Sharpened Noses under Rarefied Gas Effects and Nonequilibrium Real Gas Effects employs a theoretical modeling method to study hypersonic flows and aeroheating on sharpened noses under rarefied gas effects and nonequilibrium real gas effects that are beyond the scope of traditional fluid mechanics. It reveals the nonlinear and nonequilibrium features, discusses the corresponding flow and heat transfer mechanisms, and ultimately establishes an analytical engineering theory framework for hypersonic rarefied and chemical nonequilibrium flows. The original analytical findings presented are not only of great academic significance, but also hold considerable potential for applications in engineering practice. The study explores a viable new approach, beyond the heavily relied-upon numerical methods and empirical formulas, to the present research field, which could be regarded as a successful implementation of the idea and methodology of the engineering sciences.