We model and simulate synthetic turbulent wind fields which exhibit the characteristics of real wind such as intermittency. Intermittent wind displays a higher probability of extreme events. In the next step, these wind fields are fed into Large Eddy Simulations.

Furthermore, we investigate the interaction of elastic wind turbine rotors with the incoming wind. This interaction is determined by the characteristics of the rotor and the incoming wind. In Fluid Structure Interaction Simulations, a Computational Fluid Dynamics routine is coupled to a structural solver which allows an investigation of the aeroelastic effects at the rotor. Turbulent inflow conditions pose a challenge here.

In detail:

• Intermittency
• Fluid Structure Interaction simulations

Projects:

• EMUwind

Publications and conference contributions:

• Bock, Marcel (presenting); Yassin, Khaled; Kassem, Hassan; Theron, Johannes; Lukassen, Laura J.: Investigation of the behavior of wind fields as turbulent inflow for LES.
  In: 18th EAWE Ph.D. seminar (European Academy of Wind Energy) (2022)
   
• Yassin, Khaled; Helms, Arne; Moreno, Daniela; Kassem, Hassan; Höning, Leo; Lukassen, Laura J.:
  Applying a Random Time Mapping to Mann modelled turbulence for the generation of intermittent wind fields.
  In: Wind Energ. Sci. Discuss. [preprint], doi: 10.5194/wes-2021-139, in review (2021)
   
• Modeling and Analysis of Turbulent Wind Conditions in Numerical Simulations. 
  In: Master Thesis University Oldenburg (2021)
   
• Helms, Arne; Moreno, Daniela; Yassin, Khaled (presenting); Kassem, Hassan; Höning, Leo; Lukassen, Laura J.: Applying the CTRW time-mapping to Mann modelled turbulence for the generation of intermittent wind fields.
  In: Wind Energy Science Conference, May 2021
   
• Höning, Leo (presenting); Herráez, Iván; Lukassen, Laura J.: Investigation of the tip vortex trajectory by means of a fluid-structure coupled wind turbine simulation in shear.
  In: 16th EAWE Ph.D. seminar (European Academy of Wind Energy) (2020)
   
• Lukassen, Laura J.; Wilczek, Michael:
  Lagrangian Intermittency Based on an Ensemble of Gaussian Velocity Time Series.
  In: Progress in Turbulence VII, Springer Proceedings in Physics 196:23-29 (2017)

We process big amounts of data from free-field measurements and experimental measurements by statistical methods and stochastic process modeling techniques to investigate the dynamics of the underlying processes.

In detail:

• Clustering method:
  We investigate the correlation of power output fluctuations of wind turbines in a wind farm by statistical analysis and clustering algorithms.
• Langevin equation:
  We create wind fields with certain characteristics in the wind tunnel with the help of an active grid and investigate their influence onto model wind turbines. The measurement data is evaluated by stochastic methods such as the Langevin equation.

Projects:
WIND-ELEKTROLYSE
Ph.D. project at Deutsche Bundesstiftung Umwelt

Publications:

• Jüchter, Julian; Peinke, Joachim; Lukassen, Laura J.; Hölling, Michael:

  Reduction and analysis of rotor blade misalignments on a model wind turbine.
  In: Journal of Physics: The Science of Making Torque from Wind (Conference Series) 2265, 022071 (2022)

• Seifert, Janna K.; Kraft, Martin; Kühn, Martin; Lukassen, Laura J.:
  Correlations of power output fluctuations in an offshore wind farm using high-resolution SCADA data. 
  In: Wind Energy Science 6, 997-1014 (2021)
   
• Lukassen, Laura J.; Stevens, Richard J.A.M.; Meneveau, Charles; Wilczek, Michael: Modeling space-time correlations of velocity fluctuations in wind farms.
  In: Wind Energy 21:474--487 (2018)
   
• Lukassen, Laura J.; Oberlack, Martin:
  Colored-noise Fokker-Planck equation for the shear-induced self-diffusion process of non-Brownian particles.
  In: Physical Review E 89(5):052145 (2014)

We investigate the influence of atmospheric boundary layer flows onto wind turbines and wind farms. This necessitates the simulation of huge domains such that fully resolved wind turbine simulations are not possible anymore. The figure shows different methods to model wind turbines for such simulations. Besides the influence of the atmospheric flow onto a wind turbine, we are interested in the influence of wind turbines or wind farms onto the surroundings. In this context we investigate the so-called Global Blockage effect.

In detail:

• FAST-PALM Coupling
• Global Blockage

Publications and Final Theses:

• Evaluation and Improvement of the Smearing for the Turbine Models in PALM based on the Model proposed by Meyer Forsting.
  In: Master Thesis Universität Oldenburg (2023)
   
• Kemme, Linus; Strnad, Simon; Vollmer, Lukas; Schmidt, Jonas; Lukassen, Laura J.:
  Sensitivity of Wake Modelling Setups.
  In: Journal of Physics: The Science of Making Torque from Wind (Conference Series) 2265, 022007 (2022)
   
• Improved Wind Farm Power Predictions by Wake Model Parameter Optimisation.
  In: Master Thesis University Oldenburg (2022)
   
• Validation and Development of Wind Farm Wake Superposition Models.
  In: Master Thesis University Oldenburg (2022)
   
• Centurelli, Gabriele; Vollmer, Lukas; Schmidt, Jonas; Dörenkämper, Martin; Schröder, Maike; Lukassen, Laura J.; Peinke, Joachim:
  Evaluating Global Blockage engineering
  parametrizations with LES.
  In: J. Phys.: Conf. Ser. 1934, 012021 (2021)
   
• Krüger, Sonja; Steinfeld, Gerald; Kraft, Martin; Lukassen, Laura J.:
  Validation of a coupled atmospheric-aeroelastic model system applied to wind turbine power and load calculations.
  In: Wind Energy Science 7, 323-344 (2022)
   
• Doubrawa, Paula; Quon, Eliot W.; Martinez-Tossas, Luis A.; Shaler, Kelsey; Debnath, Mithu; Hamilton, Nicholas; Herges, Thomas G.; Maniaci, Dave C.; Kelley, Christopher L.; Hsieh, Alan S.; Blaylock, Myra L.; van der Laan, Paul; Andersen, Søren Juhl; Krüger, Sonja; Cathelain, Marie; Schlez, Wolfgang; Jonkman, Jason; Branlard, Emmanuel; Steinfeld, Gerald; Schmidt, Sascha; Blondel, Frédéric; Lukassen, Laura J.; Moriarty, Patrick:
  Multimodel validation of single wakes in neutral and stratified atmospheric conditions.
  In: Wind Energy 23: 2027--2055 (2020)
   
• Numerical analysis of the global blockage effect of a large wind farm.
  In: Master Thesis University Oldenburg (2020)