CFD Analysis of NACA-0012 Airfoil with Various Porous Gurney Flap Geometries

The use of Gurney flap for improving lift to drag ratio of airfoils has remained a success over the past years. Although its implementation on airfoil successfully enhances lift characteristics, however, it also creates additional drag by hindering the flow. Therefore, minimization of its drag penalty is an active area of research for enhancing its effectiveness. Techniques such as modifications in its shape, size and placement position has been incorporated in its design. These techniques lower the surplus drag of Gurney flap but it is not a significant decrease. Thus keeping the need of hour in view, this endeavor has been put in to minimize the drag penalty imposed on the installation of gurney flap. A shape modification has been analyzed and successfully proposed to maximize lift to drag ratio of the airfoil with gurney flap. The idea is to introduce the porosity in the gurney flap so as to minimize the stagnation pressure loss. The flow patterns and aerodynamic parameters have been evaluated and plotted using CFD techniques in ANSYS FLUENT software. The analysis has been done with various porosity levels on the flap height of 0.5, 1, 1.5, 2 and 3% of the chord. The results and the characteristics behavior have been compared and verified from with published results. From analysis it has been found that the most effective gurney flap configration is of height equal to 2-3% of the chord with 20% porosity. This analysis could be used as a guideline in development of better and effective design of Gurney Flap being used in aerospace industry.