Numerical Study on the Aerodynamic Characteristics of Dimpled NACA0018 Airfoil at Low Reynolds Number

摘要

At higher angle of attack, especially during take-off, pressure drag is the predominant drag force experienced by an airfoil.The formation of wakes as well as the improper pressure recovery over the airfoil, caused by separation of flow, is the major factors contributing to pressure drag.Any effort to reduce pressure drag involves the delaying of flow separation.Dimple structures are successfully employed in golf balls to reduce the pressure drag and provide longer flight.The study of aerodynamics of golf ball showed that the dimples created localized turbulence which resulted in delayed flow separation.Changes in flow characteristics of NACA 0018 airfoil with dimples are analyzed in the present study Surface pressure values for Reynolds number 200000 at different angles of attack are determined.The aerodynamic efficiencies of a dimpled airfoil at various angles of attack are evaluated, and the most suitable location and shape for the dimple is found out.