Hostname: page-component-7479d7b7d-c9gpj Total loading time: 0 Render date: 2024-07-13T06:39:48.355Z Has data issue: false hasContentIssue false

Subsonic Compressible Flow Past Bluff Bodies

Published online by Cambridge University Press:  07 June 2016

A. L. Longhorn*
Affiliation:
Department of Mathematics, University of Manchester*
Get access

Summary

In this paper the Janzen-Rayleigh method is used to calculate the velocity potential for the steady subsonic flow of a compressible, inviscid fluid past a prolate spheroid. The fluid velocity at a point on the body is calculated. The analytic form obtained for this velocity differs, from that giving the velocity which an incompressible fluid would possess at the same point on the body, by a correction factor. The factor is an infinite series of first derivatives of Legendre functions of the first kind and odd order. The first three coefficients in this series are computed for bodies of certain axis ratios, and graphs of the values of these coefficients against axis ratio are plotted. The behaviour of the nth coefficient for large values of n is given. Results for slender ellipsoids, considering these as a limiting case of the family of ellipsoids just referred to, are obtained and are found to agree with the usual slender-body theory. Using these an attempt is made to continue the graphs of the first three coefficients in the correction factor series for the whole range of axis ratios of the ellipsoids in the system, namely zero to unity. The results obtained for the bluff-nosed ellipsoids may be used to estimate the effects of compressibility on the pressure distribution over the front of a general bluff-nosed body in steady flow.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1954

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

1. Janzen, O. (1913). Beitrag zu einer Theorie der stationären Strömung kompressiblen Flüssigkeiten. Phys. Zeit., XIV, pp. 639643, 1913.Google Scholar
2. Rayleigh, Lord (1916). On the Flow of Compressible Fluid past an Obstacle. Phil. Mag. (6), xxxii, pp. 16, 1916.Google Scholar
3. Goldstein, S. and Lighthiix, M. J. (1944). Two-dimensional Compressible Flow past a Solid Body in Unlimited Fluid or Symmetrically Placed in a Channel. Phil. Mag., Vol. XXXV, Seventh Series, pp. 549568, 1944.Google Scholar
4. Lamla, E. (1939). Die symmetrische Potentialströmung eines kompressiblen Gases um Kreiszylinder und Kugel im unterkritischen Gebiet. Deutsche Luftfahrtforschung, F.B., No. 1014, 1939.Google Scholar
5. Schmieden, C. (1942). Die kompressible Strömung um ein Rotationsellipsoid nach der Methode von Janzen-Rayleigh. Jahrbuch 1942 der Deutschen Luftfahrtforschung, 1.72-1.79, 1942.Google Scholar
6. Sauer, R. (1944). The Numerical Evaluation of the Rayleigh Method of Two-dimensional and Axi-symmetrical Three-dimensional Flows of Compressible Media. R.T.P. Trans. No. GDC 10/4079 T, 1944.Google Scholar
7. Lamb, H. (1932). Hydrodynamics, 6th Edition, Cambridge, p. 141, 1932.Google Scholar
8. Whittaker, E. T. and Watson, G. N. (1935). A Course of Modern Analysis, 4th Edition, Cambridge, p. 322, 1935.Google Scholar
9. Jeffreys, H. and Jeffreys, B. S. (1946). Methods of Mathematical Physics, Cambridge, p. 623, 1946.Google Scholar
10. Sears, W. R. (1947). A Second Note on Compressible Flow about Bodies of Revolution. Quarterly of Applied Mathematics, Vol. V, pp. 8991, 1947.Google Scholar