AERODYNAMIC MEASUREMENTS AND FLOW VISUALIZATIONS OF OWL-LIKE AIRFOIL

Abstract

This present study investigates the aerodynamic characteristics of an owl-like airfoil that approaches the flight Reynolds numbers of an owl wing. However, unlike the actual owl wing that is characterized by serrations, a velvet and training-edge fringe structure, and aero elastically deformable feathers, the owl-like airfoil design of this study is solid and smooth. With a view to the main-wing airfoil design such as MAVs based on the biomimetics, the aim of the present work is to experimentally determine the Reynolds number dependence on the aerodynamic performance of an owl-like airfoil at low Reynolds numbers and to investigate the flow fields that lead to aerodynamic change using flow visualization. The result shows that increase in pressure drag is associated with a laminar separation or formation of a separation bubble on the pressure side. Hence, to reduce drag, these types of flow phenomena would need to be suppressed.