Unstructured mesh parameterization for a small wind turbine simulation

Abstract

Computational studies of wind turbines have been growing considerably in recent years. This is due to the fact that the reduction of analysis time, costs in the development of wind turbines and the high reliability of the results. Then, a survey of mesh convergence was conducted, consisting of a mesh with a static external domain and a rotating internal domain for the simulation of a 5 m diameter wind turbine. The turbine studied is a model with three blades, designed with the help of software SDPA 1.0 - Development System for Wind Turbine Blades - developed in the Laboratory of Aerodynamics and Fluid Mechanics. The SDPA computes chord and the twist angle for optimum blade sections according to the theory of BEM. The blade is optimized for a specific speed value λ = 7. with NACA 63215 profile. The meshes were generated by software ANSYS ICEM CFD to different values of downstream distance, upstream distance, static domain diameter, maximal size of elements over the blades, minimal size of elements over the blades, maximal size of external domain and maximal size of internal domain. Simulations were performed by software ANSYS CFX using RANS k-ω SST turbulence model. Solution independence to mesh has been achieved and the resulting mesh has been used to plot the power curve of the wind turbine. The values of power coefficient were calculated with reasonable precision and the obtained mesh has been considered adequate to the proposed study. At the end of the study, we compare the results obtained with the BEM available and it could be verified that imulation represented very well problem proposed.