This study employs a multi-region coupled method to investigate the motion responses and aerodynamic load variations of the IEA 15 MW semi-submersible floating wind turbine (FOWT) under extreme focused wave conditions. The methodology employs the self-developed MRFoam solver within OpenFOAM to integrate aerodynamic and hydrodynamic analyses. The computational framework combines an incompressible viscous flow model with kOmegaS...