Structural performance optimisation of a composite rotor blade for retrofitting a 225-kW wind turbine

In this research, an optimisation study is carried out to improve the structural performance of a highly efficient wind turbine blade. The rotor blade is a 13-m long composite blade designed for retrofitting a 225-kW wind turbine. Its external geometry, constructed with modified NACA 63 series airfoils, was designed to enhance wind turbine power production efficiency. This research aims to optimise the internal structure of the wind turbine blade, with the objective to increase the blade stiffness. A set of design variables is used to define the blade internal structure. The optimisation methodology used in the study is based on the screen method. This is achieved by sampling different sets of variables and performing the structural analysis to adopt a variable set which has a relatively good performance. For each variable set, the blade structure performance is evaluated by finite element analysis. By applying the screen method, the blade stiffness has an improvement of 33 % while the blade self-weight has a reduction of 4%.