Linear and Nonlinear Aeroelastic Analysis of Fighter-Type Wing with Control Surface

Linear and nonlinear aeroelastic analyses of a fighter-type wing with a control surface have been performed by using frequency-domain and time-domain analyses. Modes from free vibration analysis and a doublet-hybrid method are used for the computation of subsonic unsteady aerodynamic forces. The fictitious mass modal approach is used to reduce the problem size and the computation time in the linear and nonlinear flutter analyses. For the nonlinear flutter analysis, the control surface hinge is represented by a free-play spring and is linearized by using the describing function method. The linear and nonlinear flutter analyses indicate that the flapping mode of the control surface and the hinge stiffness have significant effects on the flutter characteristics. From the nonlinear flutter analysis, limit-cycle oscillation and chaotic motion are observed in a wide range of air speed below the linear flutter boundary, and a jump of limit-cycle oscillation amplitude is observed.