Flutter Analysis of 3D Aircraft Wing Model with a Mounting Control Surface

In this paper, flutter of an aircraft wing with a control surface is considered. The wing is modeled as an elastic cantilever beam and the control surface is assumed to be a rigid beam with limited length which is connected to the aircraft wing by two torsional springs. Hamilton's principle is used to obtain the equations of motion and boundary conditions of the wing and the control surface. To precisely consider the spanwise location of the control surface in the system governing equations the Heaviside function is used. Also, Theodorsen unsteady model is used to simulate the aerodynamic lift and moment. The resulting partial differential equations are transformed into a set of ordinary differential equations through the assume mode method. Then eigenvalue analysis is employed to determine the system stability boundaries and effects of different design parameters on the system aeroelastic behavior are studied. Numerical results show that increasing the length of the control surface and its distance from the wing root decreases the flutter speed. Furthermore, increasing the torsional stiffness of springs connecting the wing to the control surface increases the flutter velocity.