RESPONSE CHARACTERISTICS OF A 2-DIMENSIONAL WING SUBJECTED TO TURBULENCE NEAR THE FLUTTER BOUNDARY

Subcritical flutter characteristics are examined by using a simple bending-torsion wing model subjected to flow turbulence with a view to application for flutter boundary prediction. The wing response due to random inputs is represented by the autoregressive moving-average model. Wing stability is evaluated with the aid of Jury's stability criterion. Jury's stability parameters are expressed in terms of the physical quantities of the deterministic aeroelastic model. Change in the stability parameters is compared with that of model dampings in the subcritical range. According to numerical results, the flutter boundary prediction by using Jury's criterion is more useful than the conventional damping method. Variances of the estimated stability parameters are calculated at several dynamic pressures to evaluate how scattering of the estimation changes. As the dynamic pressure approaches the flutter boundary, the variance of the estimated value of the parameter which predicts the boundary decreases monotonically as was observed in a previous experiment made by the senior author of the present paper. For the estimation of the flutter boundary, it is highly recommended to use the ARMA model rather than the AR model. © 1990.