This research work is aimed to improve the actuator surface modeling in order to better represent the flow around the wind turbine rotor. A comprehensive study on development of wake region of the airfoil and the wind turbine rotor has been carried out using the proposed hybrid model. This model presents a coupling between the blade element method and the Navier-Stokes solver, using an iterative computation. In the Navier-Stokes solver, aerodynamic forces applied on the flow by a blade are imposed on the surface, which represents the blade. In the existing actuator surface model, aerodynamic forces are principally represented by the normal force of the airfoil, distributed as a pressure discontinuity on the surface. In this PhD thesis, in order to improve the reproducing of aerodynamic behavior of airfoil, in addition to pressure discontinuity, the tangential forces are imposed as 'source terms' in vicinity of the actuator surface. Firstly, the proposed method is validated in the case of flow around airfoil. The flow field resulted from CFD calculation of real geometry is compared with flow field obtained using different hybrid methods and this comparison shows a good agreement. The comparison with existing hybrid methods shows that the proposed approach represents better the flow field around the airfoil and permits to extend the model application to important angles of attack. Furthermore, using the proposed method, the near wake development downstream horizontal axis wind turbine model is also studied. The obtained results are compared with experimental measurements carried out in wind tunnel facilities of 'Arts et Métiers ParisTech'. In this study, the flow field downstream the wind turbine rotor is obtained by means of Particle Image Velocimetry (PIV). The comparison between numerical and experimental results shows good agreement and validity of the proposed hybrid method.
