BEM Simulation and Performance Analysis of a Small Wind Turbine Rotor

The blade element momentum (BEM) method is a popular tool for predicting the performance of wind turbine rotors. This study investigated the impact of including factors such as tip loss, hub loss and drag coefficients in BEM simulations of a Bergey XL.1 small wind turbine. The Bergey XL.1 has constant chord, untwisted blades that are challenging to simulate owing to the large variation in angle of attack along the blade during operation. Methods of including post-stall airfoil characteristics, and three wake approaches (Buhl, Glauert and Wilson-Walker) were also examined. BEM simulations were consistent with test data from a Bergey XL.1 collected using a vehicle-based platform. Including tip losses, drag coefficients and wake effects in the BEM simulation had a significant impact on predicted performance, while the effect of including hub loss was negligible. The results illustrate that BEM methods can predict the performance of small wind turbine rotors.