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Lifting-line theory for an unsteady wing as a singular perturbation problem

Published online by Cambridge University Press:  29 March 2006

E. C. James
Affiliation:
Tetra Tech Incorporated, 630 North Rosemead Boulevard, Pasadena, California 91107

Abstract

A linearized theory, which treats unsteady motions of a wing of large aspect ratio at variable forward speed in an inviscid incompressible fluid, is developed, using the method of matched asymptotic expansions. The wing geometry and motions are specified; and the time-dependent lift and moment are obtained. Long-time asymptotic behaviour of an initial-value harmonic motion is presented, as are the short-time solutions of a wing starting from rest, with constant acceleration and with impulsive acceleration to constant speed. Some attention is given to flapping flight. Results are presented in quadrature form for a general class of unsteady wing motions.

Type
Research Article
Copyright
© 1975 Cambridge University Press

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