• Large Eddy Simulation
• LES
• rotor modeling
• subgrid scale models
• turbulence effect on power production
• turbulent inlet
• wake effect
• wind turbines

Nowadays investments in wind energy are growing and to minimize capital
cost the distance between wind turbines in wind farms is reduced. This
emphasizes the key role of the wake on power production in clustered configurations.
In the present thesis, Large Eddy Simulations (LES) of the flow
around two in-line wind turbine models have been performed to assess the
effect of wakes on power production variability. Numerical results are validated
against an experiment carried out at the Norwegian University of
Science and Technology.
Three different inlet conditions have been considered in order to evaluate
the influence of turbulence on the flow field. To reproduce high turbulence
at the inlet two grids, with different shape and solidity (ratio between the
frontal area of the grid and the area of the test section), were modeled
upstream of the first turbine. A simulation with uniform inflow boundary
conditions has been performed as reference.
The results obtained have been discussed and compared with the experimental
data. In order to appraise the impact on the LES results, various
subgrid scale models have been implemented as well as different models for
the rotating blades of the wind turbines.