Abstract: Numerical simulation of vertical tail buffeting under large angles of attack is accomplished using a delta wing/vertical tail configuration. The unsteady aerodynamic load upon the tail surface is calculated by employing a well-validated laminar Navier-Stokes equation solver. The structural dynamic equation is decoupled in the generalized coordinates and proceeds on the time-domain by four-stage Runge Kutta. The aeroelastic response of the flexible tail is predicted by coupling the two equations. The results show that the asymmetrical flow field formed by the interaction between the breakdown flow and the tail forces the structural deflection offsetting outboard. The bending and torsion responses of the tail structure are coupled and their frequency meets the pressure fluctuation upon the tail surface. Therefore, the interaction of bending and torsion responses governs the flow field surrounding the vertical tail. The slight amplitude vibrations are dominated by the first bending mode while accelerations with large quantitation are dominated by the torsion mode and subject the vertical tail to severe additional inertial load.

Key words: tail buffeting, large-swept delta wing, large angle of attack, bending-torsion coupling, vibration acceleration