Improved BEM Method for HAWT Performance Predictions

Abstract

This paper proposes a new stall delay model for a better prediction of aerodynamic performances for small Horizontal Axis Wind Turbine (HAWT) Blade. The proposed model corrects the 2D lift coefficient of the wind turbine blade section to take into account the 3D blade rotation i.e., stall delay effect. It has been carried out based on analysis done between the 3D and the 2D lift coefficient measurements. This new stall delay model is an original model developed for lift coefficient correction only. The proposed approach was implemented in a blade element momentum (BEM) method, through a computer code written in MATLAB. In comparison with measurement data of the NASA Ames wind tunnel and NREL phase VI wind turbine, and with predictions of previous stall delay models, the obtained results have shown noticeable improvement in the prediction of the 3D lift coefficients, as well as the resulting power and torque curves.