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An Alternative Analytical Method for Ground-Effect Aerofoils

Published online by Cambridge University Press:  07 June 2016

T Kida  and
Y Miyai
T Kida
Affiliation:
College of Engineering, University of Osaka Prefecture
Y Miyai
Affiliation:
College of Engineering, University of Osaka Prefecture
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Summary

An alternative analytical method is applied to interference problems of an aerofoil very close to the ground, such as a free surface, a solid wall, and a slipstream. The method of matched asymptotic expansions on the small ground clearance is used in the governing integral equation and this analysis is different from Widnall and Barrows’s analysis. They used the matched asymptotic method in the differential equation. To show that the present method is reasonable, the problem of a ground-effect aerofoil in uniform fluid flow is considered and it is found possible to obtain the same results as those of Widnall and Barrows for the case of small ground clearance. By comparing with some earlier studies, it is found that the asymptotic method used with small ground clearance is valid for a clearance less than about 0.3 of the chord length. Next, the interference of ground-effect aerofoils in the channel wall, in a free jet stream, and in a slipstream are examined, and it is found that the present method can be easily applied to these problems.

Type
Research Article
Information
Aeronautical Quarterly , Volume 27 , Issue 4 , November 1976 , pp. 292 - 308
Copyright
Copyright © Royal Aeronautical Society. 1976

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References

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