The Impact of Blade Thickness on the Structural and Aerodynamics Performance of a Morphing Wind Turbine Blade

The increasing demand for "clean" energy has become a global issue that triggers the rapid growth of renewable energy development. Engineers and designers envisage new technology to improve the performance of wind energy systems.;In order to contribute to the development of renewable energy, it is important to discover the most effective type of morphing wind turbine blade. To optimize the design of a wind turbine, it requires extensive study of the interaction between the aerodynamic forces induced by the wind field and the structural response of the wind turbine blade. Coupled fluid-structure interaction (FSI) modeling can provide details about the behaviors of a morphing wind turbine blade. The two main techniques for solving the fluid-structure interaction (FSI) problem are the segregated-coupled and fully-coupled approaches. Since most of the past studies are mainly focused on the segregated-coupled approach, this study attempts to investigate the aerodynamics and structural impact of blade thickness on a morphing wind turbine blade using the fully-coupled approach.;Three symmetrical morphing airfoils selected in this study are NACA 0012, NACA 0018 and NACA 0024 representing different thicknesses. These three different airfoil profiles are subject to a fixed wind speed at various attack angles from 2 to 20 degree in two-degree increments. Reynolds number of Re = 5.0 x 105 is used in all cases. Three different Young's modulus values are E1 = 1.64 x 105 Pa, E2 = 2.46 x 105 and E3 = 3.29 x 105 used to represent different material flexibility. There are a total of 90 simulation morphing airfoil models being generated.;This study shows that symmetrical morphing airfoil in HAWT can improve drag and lift-drag ratio in the post-stall region. However, the benefits of the morphing effect diminish as airfoil thickness increases due to the higher bending resistance in thicker airfoil. The presented results prove that it is unnecessary to have thick root section for a wind turbine since a morphing airfoil can both increase aerodynamics performance in the post-stall region and alleviate stress loading to withstand strong wind.