Fatigue loads in forest regions
The project deals with LES simulations (i.e. numerical accurate solutions av Navier-Stokes equations) of the atmospheric boundary layer above and inside forest regions. From these simulations, instantaneous turbulence data are extracted, serving as inflow data in subsequent fatigue-load calculations for a wind turbine. It is expected that the presence of a forest would lead to stronger atmospheric turbulence and increased wind shear, compared to flow over low-roughness flat terrain. By simulating the atmospheric boundary layer with and without a forest, this expectation could be verified and it was possible to quantify the effect of the forest on the wind-turbine fatigue loads. It could be shown that typical loads are increased by a factor of almost three in terms of root-mean-square values and equivalent fatigue loads.