Predictions of the cycle-to-cycle aerodynamic loads on a yawed wind turbine blade under stalled conditions using a 3D empirical stochastic model

Aerodynamic measurements on wind turbines

“…The insights from the measurements have led a wide variety of models to correct 2D airfoil data. Some of these modeling activities are reported in Schepers () (based on work from Schepers et al, ) and Bjorck (), Elgammi (); Lindenburg (), Snel (), and Guntur et al () (to mention only a few).Moreover, it was found that at the outer stations an over prediction of loads occurs when using 2D data. Models to describe this geometrical tip effect on the airfoil coefficients (not to be confused with the Prandtl tip effects on induction) are described in Shen et al (), Schepers et al (, ), Schreck et al ().…”

“…The references Haans, Sant, van Kuik, and van Bussel (), Elgammi (), Guntur, Sørensen, and Schreck (), Hand et al (), Kuik, van Rooij, and Imamura (), Larwood and Chow (), Lindenburg (), Meng and van Rooij (), Rooij and van Arens (), Sant (), Sant et al (), Schepers (, , ), Schreck and Robinson (), Schreck, Robinson, Hand, and Simms (), Schreck, Sant, and Micallef (), Schreck, Sørensen, and Robinson (), Sørensen and Schreck (), van Rooij and Schepers () are related to the NREL Phase VI experiment and IEA Task 20 (although some have been produced after the end date of IEA Task 20).…”

“…This PhD thesis gives an extensive overview on the use of the IEA Task 14/18/20/29 measurements in particular for the development and validation of engineering methods. Other PhD theses which make use of aerodynamic experiments are Micallef () (using TUDelft OJF measurements), Sant () (using UAE‐VI and TUDelft OJF measurements), Elgammi () (using UAE VI), and Micallef () (using Mexico experiment and TUDelft data).…”

“…These revealed dynamic stall vortex reminiscent of those observed under operating rotor conditions. More recently, Elgammi () and Guntur et al () analyzed UAE Phase VI surface pressure data, exploiting controlled conditions to separate the effects of dynamic stall and rotational augmentation on rotor blade vortex flow fields and unsteady force production.Modeling efforts based on Mexico measurements at yawed conditions took place in Pereira et al () where the Beddoes Leisman dynamic stall model was validated and improved. Tower effects: Tower effects were found to be overpredicted in comparison to IEA Task 14/18 measurements when a standard potential dipole model common in BEM tools is used (see Graham & Brown, ). Recent research (Larwood & Chow, ) has compared the aerodynamics of the UAE Phase VI rotor for upwind and downwind configurations, focusing on aerodynamic load production during passage of the blade through the tower wake. Dynamic inflow : Dynamic Inflow (unsteady induction) effects occur at fast thrust changes due to, for example, pitching or rotor speed variations.…”

“…The insights from the measurements have led a wide variety of models to correct 2D airfoil data. Some of these modeling activities are reported in Schepers () (based on work from Schepers et al, ) and Bjorck (), Elgammi (); Lindenburg (), Snel (), and Guntur et al () (to mention only a few).…”