EFFECTS OF ROLLING ANGULAR VELOCITY ON THE FLUTTER OF WING-STORE UNDER FOLLOWER FORCE

The flutter analysis of a swept aircraft wing-store configuration subjected to follower force and undergoing a roll maneuver is presented. Concentrated mass, follower force, and roll angular velocity terms are combined in the governing equations which are obtained using the Hamilton's principle. The wing is modeled from a classical beam theory and incorporates bending-torsion flexibility. Heaviside and Dirac delta functions are used to consider the location and properties of the external mass and the follower force. Also, Peter's unsteady aerodynamic pressure loadings are considered and modified to take the wing sweep angle effect into account. The Galerkin method is applied to convert the partial differential equations into a set of ordinary differential equations. Numerical simulations are validated with available published results. In addition, simulation results are presented to show the effects of the roll angular velocity, sweep angle, follower force, and engine mass and location, on the wing flutter. Results arc indicative of the significant effect of the rigid body roll angular velocity and the follower force on the wing-engine dynamic stability. Furthermore, distances between the engine center of gravity and the wing elastic axis contribute considerable effects in the wing-engine flutter speed and frequency.