Modelling of blade root and tip losses in horizontal axis wind turbines

This study investigates how alternative blade-root and blade-tip loss corrections influence steady aerodynamic predictions for a 200-kW horizontal-axis wind turbine (HAWT) within a Blade Element Momentum (BEM) framework. A controlled comparison is performed using theoretical, semi-empirical, and performance-based loss formulations and three related RISØ-A1 blade configurations. The analysis focuses on the spanwise loss factor, lift coefficient, angle of attack, induction factor, thrust coefficient, local power coefficient, and integrated power coefficient. The results show that the hub/root correction factor is approximately 0.775 for the investigated geometry and reduces the local root-region lift coefficient by about 21%, demonstrating that root effects should not be neglected even when their contribution to integrated power is smaller than that of the outer blade. Among the tip-loss formulations, Shen- and Zhong-type corrections produce the least severe modification of the predicted aerodynamic trends, whereas classical Prandtl-based, Burton, and Lindenburg formulations produce substantially stronger changes near the tip; local differences between model groups can approach 60%. Across the investigated configurations, the RISØ-A1–24 case reaches a maximum total power coefficient of approximately 0.54 under the specified operating conditions. The study does not claim universal superiority of any correction model; instead, it quantifies model-form variability under identical BEM inputs and shows that the predicted sensitivity depends on blade geometry and operating condition. The results provide guidance for selecting and interpreting BEM loss corrections and identify experimental or high-fidelity CFD/actuator-line validation, dynamic inflow/stall treatment, and broader parametric sensitivity analysis as important next steps.