Numerical Analysis of Various Horizontal Axis Wind Turbine Blades and Optimization for Low Wind Velocity

Abstract

Among different renewable energy sources, wind energy is a promising source for harvesting energy, but the main obstacle here is that the wind velocity is not high enough everywhere. Small-scale wind turbine blade output is very small as the power output of wind power is proportional to the square of air velocity. Therefore, research is going on to develop new blades efficient enough to produce electricity at low wind velocity by optimizing blade shape. In this study, two airfoil models NACA 63-415 and NACA 63-412 were analyzed numerically using ANSYS Fluent software. Different aerodynamic properties such as static pressure, dynamic pressure, velocity magnitude, and streamlines were observed. At velocity inlet, the upstream velocity of air is 3m/s for Re=200000. The velocity components are calculated for each angle of attack. For velocity inlet boundary condition turbulence intensity is considered 1% and for pressure outlet boundary is 5%. In addition, a turbulence viscosity ratio of 10 is used for better approximation. At different angles of attack [0-18 degree] lift coefficient, drag coefficient, thus, the optimum angle of attack is measured. Blade sections made by the same airfoils are optimized by changing the twist angle. The blade section is twisted from 0 to 16 degrees on a 4 degrees interval. Therefore, the optimum twist angle is calculated 12 degrees where the lift coefficient is maximum compared with the drag coefficient.