Nonlinear Aeroelastic Study of an All-Movable Horizontal Tail with Multiple Free-Plays and Angle of Attack

In this study, a three-dimensional all-movable horizontal tail model with multiple free-plays and variable initial angle of attack was designed and manufactured. A series of wind tunnel tests were performed to investigate the nonlinear aeroelastic behavior induced by multiple free-plays. The results showed that the horizontal tail model exhibited highly nonlinear characteristics and underwent multiple limit cycle oscillations (LCOs), bifurcations and high-order harmonics. The influences of initial angle of attack on the critical velocity, amplitude and frequency of the LCOs were analyzed and summarized. The stability of the LCOs was also investigated by excitation tests. The initial angle of attack and flow velocity related to the characteristics of the high-order harmonics. The larger the flow velocity, the more significant the odd-order harmonics in the high-order harmonics; the larger the initial angle of attack, the more significant the even-order harmonics in the high-order harmonics. Therefore, in addition to the free-play angle, the initial angle of attack is also an important parameter affecting the LCO characteristics. Results and Conclusions in this paper may be valuable for predicting such LCOs induced by multiple free-plays, and providing a reference for the design of all-movable horizontal tail to prevent LCOs.