Numerical Modeling of Unsteady Air Flow with Vortices on Wind Turbine Blades

Generally, in the classical theory of the wind turbines, at the end of profiles appears an inverse flow of three-dimensional vortices, with significant effects on the turbines efficiency and the lifting coefficient. The turbines distribution in wind parks is essential, due to this wake-effect. In the present paper, this three-dimensional vortex was studied numerically by solving the Navier-Stokes equations, with supplementary corrections imposed by the characteristics of the compressible fluid flow. Supplementary have been analyzed the influence of pressure distribution, blade shape and Reynolds number on the vortices development. A comparison between the numerical and experimental results registered for almost two years was accomplished. The pressure distribution in both cases is in good agreement for blades having as a cross-section, profile NACA 0015. It was used the Navier-Stokes flow solver, associated with a grid with different mesh distribution. The effects of the stream diffusion were neglected for the separated flow, by considering large secondary vortices with the effect of the lift-off. These new considerations will allow a better understanding of vortices formation. Finally, are mentioned some conclusions and references.