KBM METHOD OF ANALYZING LIMIT-CYCLE FLUTTER OF A WING WITH AN EXTERNAL STORE AND COMPARISON WITH A WIND-TUNNEL TEST

The limit cycle flutters of two models of a wing/store with free play in the junction, one a two-dimensional wing, and the other a delta win g, are investigated. The equivalent linearization method based on the first order asymptotic solution of the KBM method and the method based on the second order asymptotic solution of the KBM method are used to analyze the limit cycle flutter of the wing with store system. The re sults are compared with those of numerical integration and a wind-tunn el test. It is shown that, in some cases, the features of the limit cy cle flutter obtained by numerical integration can be predicted by the equivalent linearization method based on the second order asymptotic s olution of the KBM method, whereas the conventional describing functio n method fails to do so. The results of the wind-tunnel test show that , for free play, the effect of high order harmonics on the limit cycle response of the aeroelasticity system is strong when the limit cycle amplitude is small. (C) 1995 Academic Press Limited