A. Sedaghat, J.E. Cooper, J. R. Wright and A.Y.T. Leung, PREDICTION OF NONLINEAR AEROELASTIC INSTABILITIES, ICAS 2000, 27 August - 1 September 2000, Harrogate International Conference Centre, UK.
PREDICTION OF NONLINEAR AEROELASTIC INSTABILITIES
A. Sedaghat, J.E. Cooper, J. R. Wright and A.Y.T. Leung
Manchester School of Engineering
Manchester University, Manchester M13 9PL, UK
This paper describes part of an investigation into the use of Normal Form Theory to predict and characterise Limit Cycle Oscillations
(LCO) in non-linear aeroelastic systems. Starting with the coupled aeroelastic integrodifferential equations of a system with nonlinearities, it is shown how to reduce the order of the system and then compute the normal forms using a class of the period-averaging method. The stability of the LCO can then be characterised by considering the behaviour around the linear flutter condition. Such an approach does away with the need for numerical simulation of the system. The methodology is demonstrated upon a simple
two-degrees-of-freedom aeroelastic wing model with cubic stiffness. A good agreement is obtained between analytical and simulation results.