Abstract
As is well known, the T-tail flutter speed depends strongly on the steady lift or dihedral angle of the horizontal tail plane. The unsteady rolling moment acting on the horizontal tail plane oscillating in yaw and sideslip plays a critical role in this phenomenon. In this paper, a numerical method based on 3D Navier-Stokes equations for computing the subsonic and transonic flow for a wing oscillating in yaw and sideslip is presented. By introducing a new coordinate system oscillating in yaw and sideslip, the existing 3D Navier-Stokes code is easily modified to account for the in-plane motions. The calculated rolling moments show good agreement with the existing experimental data obtained for incompressible flow, and the effect of compressibility, especially the effects of the shock wave in transonic flow, on the rolling moment are clarified.