Semi-analytical unsteady aerodynamic modeling for a flexible thin airfoil in arbitrary motion

A semi-analytical formulation for the unsteady aerodynamics of flat plates is extended to flexible thin airfoils. The velocity field is described by means of a complex potential, which is developed by mapping the airfoil boundary onto a circle. This well-established approach adopted in several small disturbance theories is generalized to airfoil motions of arbitrary amplitude, under the only assumptions of attached flow and constant body length. Vorticity shedding from the airfoil trailing edge is modeled using a discrete-vortex method to account for non-planar wake. A semi-analytical solution for the pressure jump on the body is obtained that may be used for parametric studies and assessment of high-fidelity solvers. Numerical results are presented for a cantilevered flexible airfoil undergoing imposed motion in a steady axial flow. © 2017 International Forum on Aeroelasticity and Structural Dynamics (IFASD). All Rights Reserved.