Reliable Wind-Turbine Performance Prediction Using a Modular Corrected Blade-Element Momentum Framework

Post-stall prediction of wind turbine performance remains challenging because momentum corrections, rotational augmentation, and high-angle airfoil treatment interact, obscuring their individual contributions to global and sectional accuracy. This study develops a modular blade-element momentum (BEM) framework that evaluates these contributions through a common-input correction hierarchy for the NREL Phase VI rotor. Six configurations combine Prandtl and Buhl corrections, Snel or Chaviaropoulos–Hansen (CH) augmentation, and full-angle or endpoint-clamped polars. Predictions are assessed against digitized experimental torque and sectional coefficients at seven wind speeds from 5 to 25 m s−1, with radial refinement analysis and an external SimRotor comparison. Prandtl–Buhl–CH reduces torque and aerodynamic power root mean square errors by 76.5% relative to the two-dimensional baseline, to 204.2 N m and 1.539 kW, respectively. The chord-normal coefficient error decreases by approximately 70.0%, to 0.163, with R2 = 0.908. CH’s twist-dependent attenuation and coupled lift and drag augmentation support improved spanwise load retention, while the full-angle polar yields substantially lower errors than endpoint clamping. However, Snel gives lower mean absolute error, and CH retains a chord-tangential error of 0.134 with R2 = −2.114. These findings identify rotational augmentation and polar closure as major controls on post-stall performance, while demonstrating that improved integrated predictions do not ensure uniformly accurate sectional loads. Source code, input data and comparison outputs are provided as Supplementary Material.