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Wind Energy Science The interactive open-access journal of the European Academy of Wind Energy
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© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  29 Jun 2020

29 Jun 2020

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This preprint is currently under review for the journal WES.

Pressure Based Lift Estimation and its Application to Feedforward Load Control employing Trailing Edge Flaps

Sirko Bartholomay1, Tom T. B. Wester2, Sebastian Perez-Becker1, Simon Konze3, Christian Menzel1, Michael Hölling2, Axel Spickenheuer3, Joachim Peinke2, Christian N. Nayeri1, Oliver P. Paschereit1, and Kilian Oberleithner1 Sirko Bartholomay et al.
  • 1TU Berlin, Institute for Experimental Fluid Dynamics and Technical Acoustics, Berlin Germany
  • 2University of Oldenburg, ForWind – Institute of Physics, Oldenburg, Germany
  • 3Leibniz Institute for Polymer Research Dresden, Germany

Abstract. This experimental load control study presents results of an active trailing edge flap feedforward controller for wind turbine applications. The controller input is derived from pressure based lift estimation methods that rely either on a quasi-steady method, based on a three-hole probe, or on an unsteady method that is based on three selected surface pressure ports. Furthermore, a standard feedback controller, based on force balance measurements, is compared to the feedforward control. A Clark-Y airfoil is employed for the wing that is equipped with a trailing edge flap of x/c = 30 % chordwise extension. Inflow disturbances are created by a two-dimensional active grid. The Reynolds number is Re = 290,000 and reduced frequencies of k = 0.07 up to k = 0.32 are analyzed. Within the first part of the paper, the lift estimation methods are compared. The surface pressure based method shows generally more accurate results whereas the three-hole probe estimate overpredicts the lift amplitudes with increasing frequencies. Nonetheless, employing the latter as input to the feedforward controller is more promising as a beneficial phase lead is introduced by this method. A successful load alleviation was achieved up to reduced frequencies of k = 0.192.

Sirko Bartholomay et al.

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Sirko Bartholomay et al.

Sirko Bartholomay et al.


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Latest update: 01 Dec 2020
Publications Copernicus
Short summary
This paper presents two methods on how to estimate the lift force that is created by a wing. These methods were experimentally assessed in a wind tunnel. Furthermore, an active trailing edge flap, as seen on airplanes for example, is used to alleviate fluctuating loads that are created within the employed wind tunnel. Thereby, an active flow control device is examined that can be potentially serve on wind turbines to lower fatigue or lower the material used for the blades.
This paper presents two methods on how to estimate the lift force that is created by a wing....