1 American Institute of Aeronautics and Astronautics Effect of trailing edge serration on the lift and drag characteristics of NACA0012 airfoil wing Usama Hussain 1 , Saif Ul Malook 1 , Burhan Shabir 1 , and Ozaif Ali 1 Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, KPK, 23460, Pakistan A Computational and experimental study of NACA0012 wing section with serrated trailing edge is presented. Two types of serrations triangular, and serrations with quadratic curvature added to the triangular edges were investigated for their influence primarily on Lift to Drag ratio of the wing. Both computations and experimentation were conducted at constant chord Reynolds number of 360,000. A two equation turbulence model, k-ω, was used to solve Reynolds Averaged-Navier-Stokes equations. Different dimensions of serrations were first tested in the simulated environment of ANSYS CFX, and then optimized serrated designs were manufactured to validate the results by Wind tunnel testing. Nomenclature Aspect ratio = Length of serration parallel to chord / Length of serration parallel to trailing edge Bird type serration = Quadratic spline serration CD = coefficient of drag CL = coefficient of lift D = depth of serration perpendicular to the span and chord, inch Deg = Degree Ρ = density of air, kg/m 3 Μ = viscosity of air, kg/(ms) H = height of serration parallel to chord, inch W = width of serration perpendicular to chord and parallel to trailing edge, inch L = length, inch Tri = Triangular y = Chord wise distance from the tip of serration I. Introduction Recently, modifications to the edges of the wings have been under scrutiny in order to improve the wing’s aerodynamic and acoustic parameters. Previous studies have shown that airfoils with truncated trailing edges could give higher coefficient of lift, at constant chord Reynolds number, as compared to conventional airfoils, but the added bluntness due to truncation will now increase the coefficient of drag as well [1] . Higher coefficient of drag can be attributed to the Von Karman type vortex shedding in the wake region of the wing. Reducing the intensity of these Von Karman vortices, by using serrated wing edges, have proved effective in keeping the coefficient of drag checked, and thus have improved lift to drag ratio. Tanner [2] , for example, employed serrated trailing edges onto blunt trailing edge and achieved up to 65% drag reduction as compared to blunt trailing edge. Similarly Krentel & Nitsche [3] , found drag reduction of up to 30% by employing square wave and stepped trailing edges on NACA0012 wing section. Further study on the subject by Nedic and Vassilicos [4] , was focused on the fractal patterns at the trailing edge of wings. They were able to speculate and correlate the chevron angle of fractal patterns with the intensity of vortex shedding which is primarily responsible for higher coefficient of drag. Their research have concluded that an increase in iteration of fractal patterns could mollify the intensity of vortex shedding for small chevron angles, and hence would ameliorate the lift to drag ratio. 1 Student, Department of Mechanical Engineering, GIKI, KPK, Pakistan. Downloaded by TU DELFT on March 20, 2019 | http://arc.aiaa.org | DOI: 10.2514/6.2017-4470 35th AIAA Applied Aerodynamics Conference 5-9 June 2017, Denver, Colorado 10.2514/6.2017-4470 Copyright © 2017 by Usama Hussain, Saif Ul Malook, Burhan Shabir, Ozaif Ali. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. AIAA AVIATION Forum