Investigation of the trailing edge effect at the naca 4415 wind turbine airfoil

Among renewable energy sources, wind energy has an important place. Wind energy; is a clean, free and inexhaustible source of energy that does not cause acid rains and atmospheric pollution caused by fossil fuels. The importance of the wing and the wing profile is very important in the production of wind energy. Therefore, in this study, the trailing edge of NACA 4415 wing profile was thickened and its effect was investigated. Firstly, in the QBlade program, the trailing edge of the NACA 4415 wing profile is symmetrical 1 %, 2 %, 4 %, 7 % and 10 %, just below or above the chord line, 0.5 %, 1 %, 2 %, 3.5 %, 4 % and 5% thickened and the most efficient blunt trailing edge wing profile was determined. With this aerodynamic analysis, we have obtained the aerodynamic efficiency for the original airfoil profile has increased % 5 when angleofattack is 10° and the lower exceeding edge thickness is % 2 greater than normal shape. Namely, at the given angle of attack, the normal airfoil shape has Cl/Cd is 57 but thickened airfoil has 60 Lift over Drag ratio. Thus, the aerodynamic efficiency increased with thickening of the airfoil. After we have reached the optimum blunt trailing edge for the airfoil, the modified airfoil was analysed at 124,000 Reynolds numbers and with angle of attack: 0°, 2°, 4°, 6°, 8°, 10°, 12°, 14°, 16° and 18° on CFD. According to 2D analysis results, modified airfoil Cl values were higher than original NACA 4415 airfoil values, Cd values were found to be similar. The modified airfoil was produced. With a wind-tunnel, the modified airfoil has been analysed in an experiment. The results of the experiment has shown us the results of these tests and 2D CFD analysis were similar. Furthermore, the CFD results and experimental results verify each other. In this study, wings with a rotor diameter of 1.44 m were modelled with both airfoil profiles. 3D CFD analyses were carried out with a nominal wind speed of 10 m/s. According to the analysis, NACA 4415 wing profile obtained 4.42 Nm torque; 5.12 Nm torque was obtained from the modified wing profile.