Abstract: Drag reduction is important in modern aviation because it improves both fuel consumption and aerodynamic performance. Better results in lift to drag ratio can be achieved by optimising the aerodynamic shape. The boundary layer separation can be prolonged up to a certain distance in the chord by creating turbulence over the wing surface under subsonic conditions. To improve the lift-to-drag ratio, additional components could be added to the wing's upper surface. Some of the components that can increase the lift-drag ratio of the wing include fish scales, inward dimples, and vortex generators. The fish scale array is designed, incorporated, and analysed on the upper surface of the NACA 4412 wing. To investigate the transition delay of the boundary layer on the section side of the airfoil, they were analysed for the angle of attack at 20, 40, 60, 80, 100, 120. In comparison to a smooth airfoil, the lift to drag ratio also shows an improvement in performance.

Keywords: Drag reduction, Boundary layer, Lift-drag ratio, NACA 4412 wing, Smooth airfoil.

| DOI: 10.17148/IARJSET.2021.81113