Optimization of Horizontal Axis wind Turbine Airfoil by Using the Inverse Panel

Abstract

In this paper we studied the optimization of NACA 4412 which is one of the widely used airfoils in the wind energy industry in the horizontal axis wind turbines working at low Reynolds numbers and low-speed winds. Since these turbines require high torque to start working, optimization is done by inverse design panel based on increasing lift force. Assuming stability of upper level, three different designs of speed distribution were applied to the lower level and changes to the primary airfoil geometry resulted from a few repetitions. Then, by direct panel method and CDF modeling and using Spalart-Allmaras turbulent model, aerodynamic loads on designed airfoils are predicted. Also, the impact of the number of panels on accuracy of results is analyzed. Finally, results are compared with experimental aerodynamic characteristics of the primary airfoils. For all projects, the lift coefficient and the ratio of lift to drag at all angles of attack were greater than the initial airfoil and the accuracy of the new optimized airfoil is confirmed for working in low Reynolds numbers.