A Design of a Low-Reynolds Number Airfoil that Leads to the Formation of Separation Bubbles at the Leading Edge

Abstract

The aerodynamics of airfoils at low Reynolds numbers (Re) has become increasingly important from both fundamental and industrial points of view, due to recent developments in small wind turbines, small-unmanned aerial vehicles (UAVs), micro-air vehicles (MAVs), as well as researches on bird/insect flying aerodynamics. Researchers on airfoil aerodynamics have focused on conventional aircraft design with Re beyond 5×105, where separation bubble forming on the leading edge has positive impact on aerodynamic performance of the airfoil, increasing the lift. Separation bubble not form at low Re (<1.0×104), causing the value of lift to be small. The shape of the airfoil is change to get an airfoil that can cause separation at the leading edge. This is made possible by varying the maximum thickness, maximum camber and position of maximum camber to obtain different airfoils and their pressure difference computed. Reynolds numbers considered here are 1000 to 10, 000.  It is from the study that a desired airfoil is obtained that has high lift and leading edge separation. In this study, it is now possible to design airfoil that can work well at low Reynolds number that is where velocity is low.