High-fidelity Viscous Analysis of Mav Wing Nonlinear Aeroelastic Interaction with Non-uniform Unsteady Flow

The work develops a high-accuracy viscous analysis of nonlinear aeroelastic interaction of a Micro Air Vehicle’s (MAV) wing section with a non-uniform, unsteady upstream flow. In the implemented iterative procedure, a set of governing Navier-Stokes equations is solved simultaneously with nonlinear equations of motion of the structure, so that the fluid and structure are treated as a coupled dynamic system. The numerical procedure employs a highorder low-pass filter operator which selectively damps the poorly resolved high-frequency content to retain numerical accuracy and stability over a wide range of flow regimes. An efficient analytical model is used to introduce an unsteady incompressible 2D vortical flow perturbation inside the computational domain through a source term in the momentum equations. Strongly coupled, nonlinear unsteady aerodynamic and structural responses of an elasticallymounted, rigid airfoil subject to a viscous upstream flow with imposed harmonic, high-amplitude vortical gust are examined in a test study, with focus on the wing section transition to limit cycle oscillations (LCO).