Review on validation techniques of blade element momentum method implemented in wind turbines

There are two broad kinds of energy sources: renewable and non-renewable. In the renewable energy sector, significant advancements have been made in wind energy, the world's fastest-growing renewable energy production technology. Despite this rapid development, the wind industry must still strive to ensure that any device designed for commercial use is reliable and its performance satisfies its economic projections. The critical factor in achieving this target is rotor aerodynamics because the rotor is the part that mainly reacts with the wind. When designing a wind turbine, the assessment of the aerodynamic characteristics of the blades must be accurate. Errors may result in wrong estimates of the turbines' performance and economic projections. If experimental measurements cannot determine these characteristics, a designer will use alternative methods. Several modeling methods have proven viable solutions for design and analysis purposes, like Blade Element Momentum (BEM) methods. BEM methods analyze the aerodynamic performance of wind turbines, but it requires validation to examine the accuracy of its results. This paper highlights and reviews BEM validation techniques implemented in wind turbine aerodynamics analyses. BEM is validated against experimental data and other advanced models, namely, higher-order vortex and CFD (Computational Fluid Dynamics) models. Nevertheless, the experimental data are essential in wind turbine studies for both understanding the aerodynamic mechanisms and validating all these models.