Numerical investigation of unsteady aerodynamic effects caused by tower blockage

Abstract

The greater challenge that the wind turbine industry faces today is to decrease the loads caused by the unsteady aerodynamic e ects that reduce economic the e ciency of wind turbines, leading to their incapability to be competitive with respect to other energy sources. With the objective of examining one of this phenomenon, this thesis presents a deepening in the analysis of the tower wake interference with the blades, known as tower shadow, in an upwind turbine by means of a CFD study implemented with the DLR FLOWer code and its potent over-set grid tool Chimera, which enables the simpli cation of complex grids. A 2D set composed by a background, a tower and a variable number of aerofoil is subjected to essential variations in the individual and auxiliary 'holes' geometry and in simulation parameters that a ect the outcome of the simulation, represented primarily by the velocity, the drag and lift non-dimensional coe cients and the angle of attack. Finally, conclusions are drawn.