Unsteady Aerodynamics and Wind Turbine Response using Airfoil-Based Actuator Disk Model

Unsteady aerodynamic forces from turbulent inflow and wake dynamics play a critical role in wind turbine performance and reliability. In this study, a computational framework is developed that combines Large Eddy Simulations of turbulent atmospheric boundary layers with an interpolation-based refined Actuator Disk Model (ADM) to calculate airfoil-based load distributions. Unlike traditional ADMs, this approach tracks transient aerodynamic loading along the blade span by employing airfoil-specific characteristics. This model retains the computational efficiency of ADM while reproducing transient load variations like Actuator Line Models (ALM). Comprehensive validation against ALM shows that the refined model accurately captures key aerodynamic parameters along the blade span. The resolved loading is further applied to structural simulations of the NREL 5 MW turbine, revealing tip deflections ranging from 3.69% to 6.79% of blade length, with peak stress localized near the blade root. Time-resolved load signals over multiple cycles are further used for fatigue analysis, and simulations over turbine arrays reveal the role of wake-induced turbulence on fatigue damage across the farm layout. The results demonstrate that this framework offers a scalable and efficient approach for aerodynamic load prediction and structural analysis in wind farms.