Abstract. With the increasing demand for greener, sustainable, and economical energy sources, wind energy has proven to be a potential sustainable source of energy. The trend development of wind turbines tends to increase rotor diameter and tower height to capture more energy. The bigger, lighter, and more flexible structure is more sensitive to smaller excitations. To make sure that the dynamic behavior of the wind turbine structure will not influence the stability of the system and to further optimize the structure, a fully detailed analysis of the entire wind turbine structure is crucial. Since the fatigue and the excitation of the structure are highly depending on the aerodynamic forces, it is important to take blade–tower interactions into consideration in the design of large-scale wind turbines. In this work, an aeroelastic model that describes the interaction between the blade and the tower of a horizontal axis wind turbine (HAWT) is presented. The high-fidelity fluid–structure interaction (FSI) model is developed by coupling a computational fluid dynamics (CFD) solver with a finite element (FE) solver to investigate the response of a multi-megawatt wind turbine structure. The results of the computational simulation showed that the dynamic response of the tower is highly dependent on the rotor azimuthal position. Furthermore, rotation of the blades in front of the tower causes not only aerodynamic forces on the blades but also a sudden reduction in the rotor aerodynamic torque by 2.3 % three times per revolution.