Abstract

This paper presents a simple algorithm to modify an ordinary blade to a bend-twist adaptive one. Through this algorithm the rotor radius, pre-twist and chord distributions of the original blade are modified and the optimum value of the induced twist due to elastic coupling will be predicted. Modifications to the original blade have been decided in a manner that limit the output power at its rated value and improve the average power of the wind turbine, while trying to reduce the negative effects on the blade size and loading. A simple but realistic model is introduced to estimate the induced twist in adaptive blades with bend-twist coupling. This model has been embedded in a BEMT-based rotor aerodynamic code to simulate the performance of horizontal axis wind turbines with adaptive blades. Results of the modifications to an approximation of a 2-blade AWT 27 wind turbine show that it could have an increase of about 13% in energy capture capabilities if it employs the adaptive blades based on the present modification.