Time domain modeling of unsteady aerodynamic forces on a flapping airfoil

Abstract

The goal of this research is to develop a versatile and fast code to compute the unsteady lift and thrust forces generated by a flapping airfoil and apply it to engineering problems. We consider both plunging and pitching types of motion and develop a time marching simulation based on early work in unsteady aerodynamics. The ability of the code to compute lift and thrust forces is validated against published results. We then study ways to maximize thrust generation by considering sinusoidal and square motions and optimizing parameters such as flapping frequency, amplitude, and phase difference between pitch and plunge. Finally, the code is applied to the take-off problem of a micro- UAV to illustrate the ability of the code to compute transient forces. The novelty of this research resides in the consideration of square motions and the optimization of parameters to maximize thrust. Also, the ability of the code to show transient forces and yet run faster than real time makes it a valuable tool for a wide variety of applications.