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Aeroelastic stability of coupled flap-lag motion of hingeless helicopter blades at arbitrary advance ratios

✍ Scribed by P. Friedmann; L.J. Silverthorn


Book ID
104153741
Publisher
Elsevier Science
Year
1975
Tongue
English
Weight
896 KB
Volume
39
Category
Article
ISSN
0022-460X

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✦ Synopsis


Equations for large amplitude coupled flap-lag motion of a hingeless elastic helicopter blade in forward flight are derived. Only a torsionally rigid blade excited by quasi-steady aerodynamic loads is considered. The effects of reversed flow are included. By using Galerkin's method the spatial dependence is eliminated and the equations are linearized about a suitable equilibrium position.

The resulting system of equations is solved by using multivariable Floquet-Liapunov theory, and the transition matrix at the end of the period is evaluated by two separate methods. Results illustrating the effects of forward flight and various important blade parameters on the stability boundaries are presented.