Hostname: page-component-848d4c4894-5nwft Total loading time: 0 Render date: 2024-05-05T01:52:17.273Z Has data issue: false hasContentIssue false

Non-equilibrium dissociating flow over spheres

Published online by Cambridge University Press:  26 April 2006

C.-Y. Wen
Affiliation:
Department of Mechanical Engineering, Da-Yeh Institute of Technology, Taiwan.
H. G. Hornung
Affiliation:
Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA

Abstract

Previous work on the correlation of dissociative non-equilibrium effects on the flow field in front of blunt bodies considered the dependence of the dimensionless shock stand-off distance on the dimensionless dissociation rate immediately after the normal shock in the simple case of a diatomic gas with only one reaction. In this paper, the correlation is corrected to take into account the additional parameter of the dimensionless free-stream kinetic energy, and extended to the case of complex gas mixtures with many species and many reactions, by introducing a new reaction rate parameter that has a clear physical meaning, and leads to an approximate theory for the stand-off distance. Extensive new experimental results and numerical computations of air, nitrogen and carbon dioxide flow over spheres were obtained over a large range of total enthalpy. The results comprise surface heat flux measurements and differential interferograms. Both experimental results and numerical computations substantiate the approximate theory.

Type
Research Article
Copyright
© 1995 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Candler, G. V. 1988 The computation of weakly ionized hypersonic flows in thermo-chemical non-equilibrium. PhD thesis, Stanford University.
Candler, G. V. & MacCormack, R. W. 1988 The computation of hypersonic ionized flows in chemical and thermal non-equilibrium. AIAA Paper 87-1546.
Fay, J. A. & Riddell, F. R. 1958 Theory of stagnation point heat transfer in dissociated air. J. Aero. Sci. 25, 7385.Google Scholar
Hornung, H. G. 1972 Non-equilibrium dissociating nitrogen flows over spheres and circular cylinders. J. Fluid Mech. 53, 149176.Google Scholar
Hornung, H. G. 1992 Performance data of the new free-piston shock tunnel at GALCIT. AIAA Paper 92-3943.
Hornung, H. G., Cummings, E. B., Germain, P., Sanderson, S. R., Sturtevant, B. & Wen, C.-Y. 1994 Recent results from hypervelocity research in T5. AIAA Paper 94-2523.
Hornung, H. G., Wen, C. & Candler, G. V. 1994 Hypervelocity flow over spheres. Acta Mechanica [Suppl] 4, 163170.Google Scholar
Park, C. 1988 Assessment of a two-temperature kinetic model for dissociating and weakly ionizing nitrogen. J. Thermophys. Heat Transfer 2, 816.Google Scholar
Park, C. 1989 Assessment of a two-temperature kinetic model for ionizing air. J. Thermophys. Heat Transfer 3, 233244.Google Scholar
Park, C., Jaffe, J., Howe, J. & Candler, G. V. 1991 Chemical kinetic problems of future NASA missions. AIAA Paper 91-0464.
Rein, M. 1989 SURF: A program for calculating inviscid supersonic reacting flows in nozzles.. GALCIT Rep. FM 89-1 (see also Phys. Fluids A 4, 873–886, 1992).
Rock, S. G., Candler, G. V. & Hornung, H. G. 1992 Analysis of thermo-chemical non-equilibrium models for carbon dioxide flows. AIAA Paper 92-2852.
Rousset, B. 1995 Calibration and study of the contoured nozzle of the T5 free-piston hypervelocity shock tunnel. AeE thesis, Graduate Aeronautical Laboratories, Caltech.
Wen C.-Y. 1994 Hypervelocity flow over spheres. PhD thesis, Graduate Aeronautical Laboratories, Caltech.
Wen, C. & Hornung, H. G. 1993 Experiments on hypervelocity dissociating flow over spheres. Proc. 19th Intl Symp. on Shock Waves, Marseille, to appear.