Aerodynamics and structural analysis of wind turbine blade

Abstract

The ultimate objective of the paper is to increase the reliability of wind turbine blades through the development of the airfoil structure, to calculate an optimum blade shape for the procedure begins with the choice of airfoils characteristics. Then an initial wind blade design is determined using blade element momentum. The blade plays a pivotal role, because it is the most important part of the energy absorption system. Practical horizontal axis wind turbine (HAWT) designs use airfoils to transform the kinetic energy in the wind into useful energy and it has to be designed carefully to enable to absorb energy with its greatest efficiency. There are many factors for selecting a profile. One significant factor is the chord length and twist angle which depend on various values throughout the blade. In this work, the airfoil sections used in horizontal axis wind turbine (HAWT) are S818; S825 and S826 airfoils used in NREL phase 2 and phase 3 wind turbines. They have several advantages in meeting the intrinsic requirements for wind turbines in terms of design point, off-design capabilities and structural properties. The lift and drag coefficients data for these airfoils sections are available and Matlab code were used to obtain the coordinates of a wind turbine blade. Aerodynamic and static structural analyses are presented. The commercially available software FLUENT is employed for calculation of the flow field using the Reynolds-averaged Navier Stokes (RANS) in conjunction with the k-omega shear stress transport (SST), based on finite-element method (FEM). Both grid and time step were optimized to reach independent solutions. The present work represents the basis to develop an accurate three dimensional Horizontal-Axis Wind Turbine (HAWT) model and may be used to support wind tunnel experiments.