CFD wake modeling using a porous disc

Summary of the work Single wake of a wind turbine over flat terrains is modeled with a finite-volume Computational Fluid Dynamics (CFD) Reynolds Averaged Navier-Stokes (RANS) solver. The RANS equations of an uncompressible flow are solved with a multigrid coupled algorithm; the turbulence is closed with the k-ε model. The tower and the nacelle of the wind turbine are modeled by solid cells while the rotor is modeled by a porous disc providing a resistive force which is calculated from the thrust coefficient value CT. Comparisons of CFD results are presented against wind tunnel data extracted from literature. The numerical results are further compared against three analytical models for wakes. The presented CFD model shows a very good agreement with wind tunnel data in the region between two and eight diameters downstream of the rotor while further downstream there is a tendency in slightly overestimating the wind deficit. The comparison with the analytical models is shown for four cases: two values of terrain roughness (onshore and offshore) and two values of thrust coefficient (0.80 and 0.31). Three analytical models have been considered. The CFD simulations with the actuator disc matches very well in particular with one of the analytical models for high values of thrust coefficient (CT = 0.80). In the cases wit