Effect of Airfoil Thickness on Aerodynamic Performance of NACA Symmetric Airfoils

Abstract

By altering airfoil designs, scientists have been putting forth endless effort to increase turbine efficiency over the past few decades. These modifications focus on maximizing efficiency specifically for regions with low air velocities, thereby enhancing overall power output. This study focused on varying the thickness of symmetrical airfoils at Reynolds number of . Five different NACA-4 series symmetric airfoils are investigated, with maximum thicknesses of 12%, 14%, 16%, 18% and 20% of the airfoil at 30% chord corresponding to NACA0012, NACA0014, NACA0016, NACA0018, NACA0020, respectively. ANSYS FLUENT was used to simulate three-dimensional flows. Numerical analyses indicated a gradual increase in the lift-to-drag ratio (Cl/Cd) with decreasing thickness of airfoils. The airfoil with the lowest thickness (12%), the NACA0012, has the highest Cl/Cd (15.23096). On the other hand, the NACA0020 exhibits the lowest lift-to-drag ratio (11.7848) despite having the largest thickness (20%).  The pressure and velocity contour plots of these two airfoils illustrate the distribution of pressure and velocity that contributes to the differences in lift generation. Researchers might find the analysis's conclusions useful in developing future airfoil and turbine designs and improving the accuracy of engineering models.