Kinematic Optimization of a Flapping Motion for Maneuverability and Sustainability Flights

Abstract

The design of a biomimetic micro air vehicle with flapping wings is an essential challenge in the military/civilian field to conduct various missions. The success of a micro-air-vehicle flight is strongly related to the maneuverability and sustainability of an unsteady aerodynamic performance of the flapping motion. Appropriate flapping kinematics need to be established that are amenable to various flight purposes under a fluctuating environment. In this research, kinematics of flapping motion are determined by the study of aerodynamic performance of a flapping airfoil for appropriate maneuverability and sustainability. The flapping motion of an airfoil is formulated by a combined sinusoidal plunging and pitching motion in various angles of the stroke plane. The optimization process is carried out to determine the efficient motions based on a well-defined surrogate model that is made from the results of two-dimensional computational-fluid-dynamics analysis. The kriging method and genetic algorithm are used for the kinematic-optimization problems. The optimization results present appropriate flapping motions for forward flight, hovering flight, and high-thrust flight, respectively. The numerical results of the optimized cases show how the unsteady aerodynamic mechanisms efficiently maximize lift and thrust-force generation.