Preliminary design of a small-sized flapping UAV: I. Aerodynamic performance and static longitudinal stability

The preliminary design of a biologically inspired flapping UAV is presented. Starting from a set of initial design specifications, namely: weight, max- imum flapping frequency and minimum hand-launch velocity of the model, a parametric numerical study of the proposed avian model is conducted in terms of the aerodynamic performance and longitudinal static stability in gliding and flapping conditions. The model shape, size and flight conditions are chosen to approximate those of a gull. The wing kinematics is selected after conducting an extensive parametric study, starting from the simplest flapping pattern and progressively adding more degrees of freedom and control parameters until reaching a functional and realistic wing kinematics. The results give us an initial insight of the aerodynamic performance and longitu- dinal static stability of a biomimetic flapping UAV, designed at minimum flight velocity and maximum flapping frequency.