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Analytical and Numerical Studies of Downwash over Rectangular Planforms

Published online by Cambridge University Press:  07 June 2016

H C Garner
Affiliation:
Royal Aircraft Establishment, Farnborough
G F Miller
Affiliation:
National Physical Laboratory
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Summary

The paper considers the distribution of downwash at the surface of rectangular planforms with prescribed subsonic aerodynamic loading. Three separate aspects of the problem are treated analytically, the results of each being tested against those derived from an accurate numerical procedure (Section 2). Asymptotic expressions for large and small aspect ratio are formulated and shown to apply over a wide range of aspect ratio (Section 3). Downwash routines from certain existing lifting-surface methods are studied, and their patterns of convergence are illustrated and compared (Section 4). A logarithmic singularity near the leading tip corner is identified, but it is observed that this can exist without serious detriment to the lifting-surface methods (Section 5).

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1972

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References

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