Unsteady numerical investigation of the full geometry of a horizontal axis wind turbine: Flow through the rotor and wake

Aerodynamics of the Mexico wind turbine was investigated using CFD techniques. The complete wind turbine was modelled. In order to accomplish this goal, the computational domain was discretized with a multi-block structured hexahedron grid, which was generated manually to ensure a good quality mesh and optimize the number of cells. Furthermore, a sliding mesh technique was applied to the moving mesh zone to calculate in detail the flow around the blades. All the relevant operating conditions were considered: turbulent wake state, nominal condition and stall state. The simulations were performed using the unsteady Reynolds-Averaged Navier-Stokes equations for incompressible flow and the SST k-omega turbulence model to close the governing equations. The CFD predictions were compared with the experimental data available from the MEXICO experiment: global forces and torques, pressure distributions around the blades and velocity distributions along the radial and axial traverses were all in a good agreement. The flow through the rotor, the interaction between the blades and the tower, and the development of the wake were then investigated. The CFD simulations have provided more accurate results, contributing to a deeper understanding of the wind turbine aerodynamics. (C) 2020 Elsevier Ltd. All rights reserved.