Structural optimization of a horizontal axis wind turbine blade made from new hybrid composites with kenaf fibers

This manuscript presents a continuation of a previous work of the same authors that aims to optimize the materials of wind turbine blades using natural fiber through a hybridization technique. This new conception consists of introducing kenaf fibers into a hybrid composite material initially made with synthetic fibers. Firstly, a detailed analysis was performed to optimize the aerodynamic shape of the wind turbine blade while maintaining an optimal aerodynamic performance. Secondly, ANSYS® Computational Fluid Dynamics (CFD) was used to calculate the aerodynamic parameters needed later in the structural justification. Finally, the blade geometry was imported to PATRAN® software within the objective of establishing a deep analysis of the blade structure taking into account the new combination of the three kinds of fibers: Carbon, glass and kenaf fibers. This fibers combination consists of a skin blade composed with kenaf and glass fibers, a spar cap made of carbon and glass fibers and a spar web made entirely with glass fibers. Compared to the non-optimized model, an evaluation based on materials resistance, weight and cost savings, has shown a weight saving of 40%, a material cost saving of 67% and a tip deflection of about 17% lower than the allowable threshold.