Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
L. Vollmer; G. Steinfeld; D. Heinemann; M. Kühn (2016)
Publisher: Copernicus Publications
Journal: Wind Energy Science
Languages: English
Types: Article
Subjects: TJ807-830, Renewable energy sources
An intentional yaw misalignment of wind turbines is currently discussed as one possibility to increase the overall energy yield of wind farms. The idea behind this control is to decrease wake losses of downstream turbines by altering the wake trajectory of the controlled upwind turbines. For an application of such an operational control, precise knowledge about the inflow wind conditions, the magnitude of wake deflection by a yawed turbine and the propagation of the wake is crucial. The dependency of the wake deflection on the ambient wind conditions as well as the uncertainty of its trajectory are not sufficiently covered in current wind farm control models. In this study we analyze multiple sources that contribute to the uncertainty of the estimation of the wake deflection downstream of yawed wind turbines in different ambient wind conditions. We find that the wake shapes and the magnitude of deflection differ in the three evaluated atmospheric boundary layers of neutral, stable and unstable thermal stability. Uncertainty in the wake deflection estimation increases for smaller temporal averaging intervals. We also consider the choice of the method to define the wake center as a source of uncertainty as it modifies the result. The variance of the wake deflection estimation increases with decreasing atmospheric stability. Control of the wake position in a highly convective environment is therefore not recommended.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Abkar, M. and Porté-Agel, F.: The influence of static stability of the free atmosphere on the power extracted by a very large wind farm, Proc. ICOWES2013, doi:10.3390/en6052338, 2013.
    • Annoni, J., Gebraad, P. M. O., Scholbrock, A. K., Fleming, P. A., and Wingerden, J.-W. v.: Analysis of axial-induction-based wind plant control using an engineering and a high-order wind plant model, Wind Energ., 19, 1135-1150, doi:10.1002/we.1891, 2015.
    • Barthelmie, R. J. and Jensen, L. E.: Evaluation of wind farm efficiency and wind turbine wakes at the Nysted offshore wind farm, Wind Energ., 13, 573-586, doi:10.1002/we.408, 2010.
    • Beare, R. J. and Macvean, M. K.: Resolution sensitivity and scaling of large-eddy simulations of the stable boundary layer, Bound.-Lay. Meteorol., 112, 257-281, doi:10.1023/B:BOUN.0000027910.57913.4d, 2004.
    • Bromm, M., Vollmer, L., and Kühn, M.: Numerical investigation of wind turbine wake development in directionally sheared inflow, Wind Energ., doi:10.1002/we.2010, 2016.
    • Churchfield, M. J., Lee, S., Michalakes, J., and Moriarty, P. J.: A numerical study of the effects of atmospheric and wake turbulence on wind turbine aerodynamics, J. Turbulence, 13, 1-32, doi:10.1080/14685248.2012.668191, 2012.
    • Corten, G. P. and Schaak, P.: Heat and Flux - Increase of Wind Farm Production by Reduction of the Axial Induction, in: EWEC 2003, 16-19 June, Madrid, Spain, 2003.
    • Deardorff, J.: Stratocumulus-capped mixed layers derived from a three-dimensional model, Bound-Lay. Meteorol., 18, 495-527, doi:10.1007/BF00119502, 1980.
    • Dörenkämper, M., Tambke, J., Steinfeld, G., Heinemann, D., and Kühn, M.: Atmospheric Impacts on Power Curves of MultiMegawatt Offshore Wind Turbines, J. Phys. Conf. Ser., 555, 012029, doi:10.1088/1742-6596/555/1/012029, 2014.
    • Dörenkämper, M., Optis, M., Monahan, A., and Steinfeld, G.: On the Offshore Advection of Boundary-Layer Structures and the Influence on Offshore Wind Conditions, Bound.-Lay. Meteorol., 155, 459-482, doi:10.1007/s10546-015-0008-x, 2015a.
    • Dörenkämper, M., Witha, B., Steinfeld, G., Heinemann, D., and Kühn, M.: The impact of stable atmospheric boundary layers on wind-turbine wakes within offshore wind farms, J. Wind Eng. Ind. Aerodyn., 144, 146-153, doi:10.1016/j.jweia.2014.12.011, 2015b.
    • Emeis, S.: A simple analytical wind park model considering atmospheric stability, Wind Energ., 13, 459-469, doi:10.1002/we.367, 2010.
    • Emeis, S.: Wind speed and shear associated with low-level jets over Northern Germany, Meteorol. Z., 23, 295-304, doi:10.1127/0941-2948/2014/0551, 2014.
    • España, G., Aubrun, S., Loyer, S., and Devinant, P.: Spatial study of the wake meandering using modelled wind turbines in a wind tunnel, Wind Energ., 14, 923-937, doi:10.1002/we.515, 2011.
    • Etling, D. and Brown, R. A.: Roll vortices in the planetary boundary layer: A review, Bound.-Lay. Meteorol., 65, 215-248, doi:10.1007/BF00705527, 1993.
    • Fleming, P. A., Gebraad, P. M., Lee, S., van Wingerden, J.- W., Johnson, K., Churchfield, M., Michalakes, J., Spalart, P., and Moriarty, P.: Evaluating techniques for redirecting turbine wakes using SOWFA, Ren. Energ., 70, 211-218, doi:10.1016/j.renene.2014.02.015, 2014.
    • Fleming, P. A., Ning, A., Gebraad, P. M. O., and Dykes, K.: Wind plant system engineering through optimization of layout and yaw control, Wind Energ., 19, 329-344, doi:10.1002/we.1836, 2016.
    • Gebraad, P. M. O., Teeuwisse, F. W., van Wingerden, J. W., Fleming, P. A., Ruben, S. D., Marden, J. R., and Pao, L. Y.: Wind plant power optimization through yaw control using a parametric model for wake effects'a CFD simulation study, Wind Energ., 19, 95-114, doi:10.1002/we.1822, 2016.
    • Gryschka, M., Witha, B., and Etling, D.: Scale analysis of convective clouds, Meteorol. Z., 17, 785-791, doi:10.1127/0941- 2948/2008/0345, 2008.
    • Hancock, P. E. and Zhang, S.: A Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Weakly Unstable Boundary Layer, Bound.-Lay. Meteorol., 156, 395-413, doi:10.1007/s10546-015-0037-5, 2015.
    • Hansen, K. S., Barthelmie, R. J., Jensen, L. E., and Sommer, A.: The impact of turbulence intensity and atmospheric stability on power deficits due to wind turbine wakes at Horns Rev wind farm, Wind Energ., 15, 183-196, doi:10.1002/we.512, 2012.
    • IEC-61400-12-1: Part 12-1: Power performance measurements of electricity producing wind turbines; IEC TC/SC 88, Tech. rep., IEC 61400-12-1, 2005.
    • Jimenez, A., Crespo, A., and Migoya, E.: Application of a LES technique to characterize the wake deflection of a wind turbine in yaw, Wind Energ., 13, 559-572, doi:10.1002/we.380, 2010.
    • Jonkman, J. M., Butterfield, S., Musial, W., and Scott, G.: Definition of a 5-MW reference wind turbine for offshore system development, Technical Report NREL/TP-500-38060, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393, doi:10.2172/947422, 2009.
    • Keck, R.-E., de Maré, M., Churchfield, M. J., Lee, S., Larsen, G., and Madsen, H. A.: On atmospheric stability in the dynamic wake meandering model, Wind Energ., 17, 1689-1710, doi:10.1002/we.1662, 2014.
    • Larsen, G., Machefaux, E., and Chougule, A.: Wake meandering under non-neutral atmospheric stability conditions-theory and facts, J. Phys. Conf. Ser., 625, 012036, doi:10.1088/1742- 6596/625/1/012036, 2015.
    • Larsen, G. C., Madsen, H. A., Thomsen, K., and Larsen, T. J.: Wake meandering: a pragmatic approach, Wind Energ., 11, 377-395, doi:10.1002/we.267, 2008.
    • Machefaux, E., Larsen, G. C., Koblitz, T., Troldborg, N., Kelly, M. C., Chougule, A., Hansen, K. S., and Rodrigo, J. S.: An experimental and numerical study of the atmospheric stability impact on wind turbine wakes, Wind Energ., doi:10.1002/we.1950, 2015a.
    • Machefaux, E., Larsen, G. C., Troldborg, N., Gaunaa, M., and Rettenmeier, A.: Empirical modeling of single-wake advection and expansion using full-scale pulsed lidar-based measurements, Wind Energ., 18, 2085-2103, doi:10.1002/we.1805, 2015b.
    • Maronga, B., Gryschka, M., Heinze, R., Hoffmann, F., KananiSühring, F., Keck, M., Ketelsen, K., Letzel, M. O., Sühring, M., and Raasch, S.: The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric and oceanic flows: model formulation, recent developments, and future perspectives, Geosci. Model Dev., 8, 2515-2551, doi:10.5194/gmd-8- 2515-2015, 2015.
    • Medici, D. and Dahlberg, J.: Potential improvement of wind turbine array efficiency by active wake control (AWC), Proc. European Wind Energy Conference, 65-84, 2003.
    • Mirocha, J. D., Rajewski, D. A., Marjanovic, N., Lundquist, J. K., Kosovic´, B., Draxl, C., and Churchfield, M. J.: Investigating wind turbine impacts on near-wake flow using profiling lidar data and large-eddy simulations with an actuator disk model, J. Renew. Sust. Energ., 7, 043143, doi:10.1063/1.4928873, 2015.
    • Schlipf, D., Schlipf, D. J., and Kühn, M.: Nonlinear model predictive control of wind turbines using LIDAR, Wind Energ., 16, 1107-1129, doi:10.1002/we.1533, 2013.
    • Smedman, A.-S., Högström, U., and Bergström, H.: Low level jets: A decisive factor for off-shore wind energy siting in the Baltic Sea, Wind Engineering, 20, 137-147, 1996.
    • Troldborg, N., Sørensen, J. N., Mikkelsen, R., and Sørensen, N. N.: A simple atmospheric boundary layer model applied to large eddy simulations of wind turbine wakes, Wind Energ., 17, 657- 669, doi:10.1002/we.1608, 2014.
    • Trujillo, J.-J., Bingöl, F., Larsen, G. C., Mann, J., and Kühn, M.: Light detection and ranging measurements of wake dynamics. Part II: two-dimensional scanning, Wind Energ., 14, 61-75, doi:10.1002/we.402, 2011.
    • Vanderwende, B. J. and Lundquist, J. K.: The modification of wind turbine performance by statistically distinct atmospheric regimes, Environ. Res. Lett., 7, 034035, doi:10.1088/1748- 9326/7/3/034035, 2012.
    • Wharton, S. and Lundquist, J. K.: Assessing atmospheric stability and its impacts on rotor-disk wind characteristics at an onshore wind farm, Wind Energ., 15, 525-546, doi:10.1002/we.483, 2012.
    • Witha, B., Steinfeld, G., Dörenkämper, M., and Heinemann, D.: Large-eddy simulation of multiple wakes in offshore wind farms, J. Phys. Conf. Ser., 555, 012108, doi:10.1088/1742- 6596/555/1/012108, 2014.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article