A method to optimise the materials layout of small wind turbine blades

Abstract

This paper presents a method to optimise the material layout of a fibreglass-reinforced composite constructed small wind turbine blade. The method was developed with the intent of reducing blade mass without compromising the blade’s structural performance or longevity. The bi-directional evolutionary layout optimisation method utilises finite element analysis to redesign the composite lay of the blade structure based on a strain energy criterion. Details of the procedure of this method are documented in the paper. The bi-directional evolutionary optimisation technique was applied to the existing structure of a 2.5 m composite blade from an Aerogenesis 5 kW wind turbine. The optimisation technique was able to reduce the current mass of the blade by 15% without any increase in blade deflection with strains kept below a fatigue endurance limit when subject to aerodynamic and centrifugal loading conditions at design conditions. The initial results from this study are promising and could help lower manufacturing costs of small wind turbine blades.