Wind Farm Control Methods - Yawing
Master thesis
Permanent lenke
http://hdl.handle.net/11250/2401207Utgivelsesdato
2016Metadata
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Sammendrag
The wake effect of yawing an upstream turbinesis of interest in order to increase power production. In thisstudy, the case of yawing is considered as asymmetric do tothe tower and rotor rotation, and measurements have beenperformed in a wind tunnel. The rotational effects when yawingare obtained by investigating the difference between a disc and arotor with the same drag and diameter. This is performed duringa tower-symmetrical setup, and shows that the wake deflectsapproximately 1 radius for the disc and significantly less for therotor at optimal tip speed ratio. The disc wake is similar to a jetshape in a crossflow and counter-rotating vortices are present,which is not the case for the rotor.
Moreover, the differences between yawing in the differentdirection are investigated and show that for positive yaw-angles,the wake spreads more out and deflects more to the side andto the floor. Furthermore, for negative yaw-angles, the wake islocated closer to downstream the rotor centre. These differencesare slightly less present during shear flow conditions, in additionto a more sideways deflected wake.