Advanced brake state model and aerodynamic post-stall model for horizontal axis wind turbines

In scientific literature, when the aerodynamic design of a horizontal axis wind turbine is discussed, different brake state models are presented. The brake state models are implemented within a BEM code which is a 1-D numerical code, based on Glauert propeller theory, and able to predict HAWT performance. This code provides reliable results only if a proper brake state model and aerodynamic post-stall model are implemented.In this research, the authors have produced a numerical code based on BEM theory in conjunction with an aerodynamic post-stall model, indispensable for taking into account radial flow along the wind turbine blades (Himmelskamp Effect), and the brake state models by Buhl, combined with the calculation of Jonkman's tangential induction factor.In scientific literature, Shen's brake state model is commonly implemented within 1-D numerical codes, based on BEM theory. Subsequently, a comparison with Shen's brake state models was carried out. With the numerical code presented in this work, the power for an NREL wind rotor was predicted. With the numerical simulation, it was possible to notice when these different brake state model furnish results close to experimental data.

► A 1-D numerical code for designing wind turbines was developed.
► An Advanced brake state model has been implemented.
► A post-stall model has been implemented.
► A comparison with other models has been performed.
► This numerical code has been validated through comparisons with experimental data.