Nonlinear Responses of a Slender Wing With a Store

The aeroelastic characteristics of the slender wing with store have been studied for several years. However, the nonlinear aeroelastic behaviors of the wing-store system have not been understood thoroughly. In this paper, the nonlinear aeroelastic model of a slender wing with a store is constructed. In the model, the geometric structural nonlinearity of the wing, and the kinematic nonlinearities of the wing and the store are considered. Two unsteady aerodynamic models are both employed to determine the aerodynamic loads. One is the linear unsteady aerodynamic model based on Wagner function, and the other is the nonlinear ONERA aerodynamic model. Simulation results are given to show that for the cases of employing the linear unsteady aerodynamic model based on Wagner function, the bifurcation diagrams are very complex and change with the variations of store position. For the cases of using the nonlinear ONERA model, the bifurcation diagrams are very simple and insensitive to the variations of the store position. Additionally, with the decrease of store spanwise coordinate, the system bending oscillation equilibrium position is reduced to zero, and the maximum absolute value of the bending response peak is also decreased. With the increase of the horizontal distance between the wing elastic center and the store mass center, the system response peak is decreased. Moreover, it is found that for the systems with the linear unsteady aerodynamic model based on Wagner function, the obtained response peak is larger and the nonlinear critical velocity is smaller than those with the ONERA model.