Performance prediction of wind turbines utilizing passive smart blades: approaches and evaluation

The induced deformation, because of the presence of elastic coupling in the structure of passive smart blades, is the key parameter that affects the wind turbine aerodynamic performance, namely rotor mechanical power and blade loading. Therefore, in order to determine the aerodynamic performance of these turbines, a structural analyser is also required to bring the effect of the induced deformation into account. When predicting the rotor mechanical power, additional complexity arises when the blades are bend-twist-coupled. In this case, an iterative coupled-aero-structure analysis must be carried out at each given wind speed. Further difficulties in simulation of these turbines are posed by the fact that the current analytical models for analysis of structures made of anisotropic composite materials are not accurate enough. This differentiates the numerical simulation of wind turbines utilizing passive smart blades from the simulation of wind turbines with conventional blades. Different strategies have been proposed and followed by investigators in simulation of wind turbines utilizing passive smart blades. These methods can be categorized by the approach adopted in treating the torsional-induced deformation. In these studies, the induced twist has been predicted, planned or a combination of both. The present paper describes, evaluates and compares these approaches.