Validating an advanced actuator-disk model on CFD simulations of fixed and moving wind turbines

Simulating floating offshore wind turbines (FOWTs) require high numerical fidelity at a manageable computational cost. While actuator-disk models (ADMs) are well known for their computational efficiency, they have not been extensively validated against experimental data for moving turbines. In this work, we validate an advanced ADM—the refined ADM (RADM), which represents the rotor disk using multiple rotating actuator lines—for two turbines under various motion conditions. Simulations of the IEA 15 MW reference turbine show that RADM achieves accuracy comparable to the actuator-line model (ALM) for both mean and turbulent flow characteristics while substantially relaxing time step constraints. Additional validation using a 1:75 model-scale turbine subjected to prescribed motions representative of FOWT behavior demonstrates good agreement with experimental measurements and high-fidelity ALM-based computational fluid dynamics. Overall, the results show that advanced ADMs such as RADM can deliver ALM-level accuracy with significantly higher numerical efficiency, offering a promising tool for large-scale FOWT simulations.