محاسبه سرعت فلاتر بال هواپيما در جريان زيرصوت

Calculation of Wing Flutter Speed in Subsonic Flow

Mutual interactions between aerodynamic and structural forces cause aeroelasticity that is very important in aircraft wings. In this paper, instability of a wing in dynamic situation that is called flutter is considered for a composite wing in subsonic flows. The "Strip Theory" approach is used to calculate the aerodynamic forces along the wing. For this reason, displacements along the wing and flutter speed are determined using tile "Assumed Mode Method ". In this method, the displacement along the wing is assumed by definite boundary conditions. The stored potential and kinetic energy in the wing, as well as the generalized aerodynamic forces and moments on the wing, are determined. By employing Lagrangeʹs equations, the wing motion is formulated. A Computer program has been developed to calculate the speed of the wing instability, the effects of the elastic axis and the center of gravity has been investigated on the stability of the wing. The flutter speed is calculated for a certain wing, which the data is available, and a suitable elastic axis has been determined for a specified center of gravity.