Limit cycle oscillations in swept wings based on fully intrinsic equations and considering the static stall effects

In this paper, the dynamic instability of swept wings by using the geometrically exact fully intrinsic beam equations and with considering the static stall effects is investigated. Study of variations of the limit cycle amplitudes by using the fully intrinsic beam equations and ONERA unsteady aerodynamic model with static stall effects in swept wings is the achievement of this article. the geometrically exact fully intrinsic beam equations involve only moments, forces, velocity and angular velocity, and in these equations, the displacements and rotations will not appear explicitly. In this study, the aerodynamic loads on the wing in an incompressible flow regime are determined by using the ONERA unsteady aerodynamic model. In order to check the instability behavior of the system, first the resulting non-linear partial differential equations are discretized by using the central finite difference method, and then time responses are obtained. The obtained results are compared with those available in the literature. Furthermore, the effects of sweep angle are studied. Finally, it is observed that by using the geometrically exact fully intrinsic beam equations, the instability of the swept wings can be determined accurately and selection of suitable sweep angle can postpone the occurrence of limit cycle oscillation.