Wake prediction of horizontal-axis wind turbine using full-rotor modeling

• Presents the wake studies of a wind turbine with an exact model of the rotor blades.
• Full rotor approach shows good agreement with the experimental results.
• Actuator disk approach with modified k–ε model underestimates the wake deficit.
• Standard k–ε model is sufficient to predict wakes when using full rotor modeling.
• There is a slow rate of velocity recovery in the wake beyond 80% at all wind speeds.

This work is devoted to the study of the wake characteristics in the near and far wake regions of a horizontal axis wind turbine, with an exact representation of the rotor blades. The computational numerical solution was carried out by solving the conservation equations for one outer stationary reference frame and one inner rotating reference frame, wherein the blades and grids were fixed in reference to the rotating frame. The results were obtained using the steady state Reynolds-Averaged Navier–Stokes equations and the turbulence was simulated via the k–ε turbulence model. The results of the full rotor approach using the standard k–ε turbulence model are compared with the results of the actuator disc approach using the standard k–ε turbulence model and two modified k–ε models used by the earlier researchers. The wake behavior was tested and validated with the experimental results of the three blade Danwin 180 kW wind turbine available in the literature. The results obtained from the full rotor model showed good agreement with the available experimental data, in comparison with the improvement achieved by the actuator disc approach using modified versions of the k–ε model.