Aerodynamic characteristics of NACA0018 with passive flow control mechanisms

Abstract

Airfoil is a streamline structure where the aerodynamic efficiency is optimized to get the major characteristics of airfoil. Aerodynamic efficiency is the ratio between lift to drag. High aerodynamic efficiency denotes that airfoil is having high lift to drag ratio that means Lift is higher and drag is less, which is very good for commercial as well as fighter aircraft. So nowadays many researchers are focusing to enhance aerodynamic efficiency. Here passive flow control techniques is used to enhance these characteristics. CLIFT (dimple) and cavity are one of the new surface modifications implemented on airfoil to enhance its lift and reduce its drag with delay in boundary layer separation. In this research, the effects of different shapes of CLIFTS and cavities are investigated and analyzed. A standard symmetrical airfoil NACA0018 is considered without and with inward and outward CLIFTS and cavities. Different shapes of CLIFTS and cavities such as circular, rectangular, triangular, compound (combination of circular and rectangular) is implemented on the suction or upper surface of the aerodynamic profile (Airfoil), which is studied numerically at a subsonic speed of 18m/s and angles of attack from 0°,5°,10°, 15°. The airfoil with and without CLIFTS and cavities of different shapes are designed and simulated in ANSYS FLUENT to determine which shape gives the optimum aerodynamic efficiency.