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Energy transfer through a dissociated diatomic gas in Couette flow

Published online by Cambridge University Press:  28 March 2006

John F. Clarke
Affiliation:
The College of Aeronautics, Cranfield

Abstract

The transfer of energy through a dissociated diatomic gas in Couette flow is considered, taking oxygen as a numerical example. The two extremes of chemical equilibrium flow and chemically frozen flow are dealt with in detail, and it is shown that the surface reaction rate is of prime importance in the latter case. The chemical rate equations in the gas phase are used to estimate the probable chemical state of the gas mixture, this being deduced from the ratio of a characteristic chemical reaction time to a characteristic time for atom diffusion across the layer. The influence of the surface reaction appears to spread outwards through the flow from the wall as gas-phase chemical reaction times decrease. For practical values of the surface reaction rate on a metallic wall, the energy transfer rate may be significantly lower in chemically frozen flow than in chemical equilibrium flow under otherwise similar circumstances.

Similar phenomena to those discussed will arise in the more complicated case of boundary layer flows, so that a treatment of the simpler type of shear layer represented by Couette flow may be of some value in assessing the relative importance of the various parameters.

Type
Research Article
Copyright
© Cambridge University Press

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References

Beckwith, I. E. 1953 J. Aero. Sci. 20, 645.
Camm, J. & Keck, J. C. 1957 Paper presented before American Physical Society, New York, Jan. 1957, reported by Rose, P. H., AVCO Research Lab. Res. Note 37.Google Scholar
Chapman, S. & Cowling, T. G. 1939 The Mathematical Theory of Non-Uniform Gases. Cambridge University Press.
Clarke, J. F. 1957 English Electric Co. G.W. Division Rep. no. LA.t.078.
Crown, J. C. 1952 Navord Report 2299.
Eyring, H., Gershinowitz, H. & Sun, C. E. 1935 J. Chem. Phys. 3, 786.
Fay, J. A. & Riddell, F. R. 1958 J. Aero. Sci. 25, 73 (also available as AVCO Research Lab. Res. Note 18, 1956).
Feldman, S. 1957 J. Fluid Mech. 3, 225.
Hirschfelder, J. O. 1956 University of Wisconsin, Report no. WIS-ONR-18.
Hirschfelder, J. O., Curtiss, C. F. & Bird, R. B. 1954 Molecular Theory of Gases and Liquids. New York: Wiley.
Illingworth, C. R. 1950 Proc. Camb. Phil. Soc., 46, 469.
Von Kármán, T. 1956 Selected Combustion Problems II. London: Butterworths.
Lees, L. 1956 Jet Propulsion 26, 259.
Liepmann, H. W. & Bleviss, Z. O. 1956 Douglas Aircraft Rep. N8.SM-19831.
Lighthill, M. J. 1956 J. Fluid Mech. 2, 1.
Moelwyn-Hughes, E. A. 1947 Physical Chemistry. Cambridge University Press.
Moore, L. L. 1952 J. Aero. Sci. 19, 505.
Penner, S. S. 1955 Chemical Reactions in Flow Systems. London: Butterworths.
Shuler, K. E. & Laidler, K. J. 1949 J. Chem. Phys. 17, 1212.