• A Detached-Eddy-Simulation study: Proper-Orthogonal-Decomposition of the wake flow behind a model wind turbine 

      Göing, Jan; Bartl, Jan Michael Simon; Mühle, Franz Volker; Sætran, Lars Roar; Thamsen, Paul Uwe (Journal article; Peer reviewed, 2018)
      In times of intense renewable energy development, the planning of wind farms and the improvement of their total efficiency has become a major field of research. A precise analysis of the velocity deficit, fluctuation load ...
    • Blind test comparison on the wake behind a yawed wind turbine 

      Mühle, Franz Volker; Schottler, Jannik; Bartl, Jan Michael Simon; Futrzynski, Romain; Evans, Steve; Bernini, Luca; Schito, Paolo; Draper, Martín; Guggeri, Andrés; Kleusberg, Elektra; Henningson, Dan S.; Hölling, Michael; Peinke, Joachim; Adaramola, Muyiwa S.; Sætran, Lars Roar (Journal article; Peer reviewed, 2018)
      This article summarizes the results of the “Blind test 5” workshop, which was held in Visby, Sweden, in May 2017. This study compares the numerical predictions of the wake flow behind a model wind turbine operated in yaw ...
    • An experimental study on the effects of winglets on the tip vortex interaction in the near wake of a model wind turbine 

      Bartl, Jan; Mühle, Franz Volker; Hansen, Thomas; Adaramola, Muyiwa S.; Sætran, Lars Roar (Peer reviewed; Journal article, 2020)
      An experimental study of the near wake up to four rotor diameters behind a model wind turbine rotor with two different wing tip configurations is performed. A straight‐cut wing tip and a downstream‐facing winglet shape are ...
    • Experimental validation of analytical wake and downstream turbine performance modelling 

      Polster, Felix; Bartl, Jan Michael Simon; Mühle, Franz Volker; Thamsen, Paul Uwe; Sætran, Lars Roar (Journal article; Peer reviewed, 2018)
      Wake effects in wind farms can cause significant power losses. In order to reduce these losses layout and control optimization can be applied. For this purpose, simple and fast prediction tools for the wake flow are needed. ...
    • Experiments in the wind turbine far wake for the evaluation of an analytical wake model 

      Garcia, Luis; Vatn, Mari; Mühle, Franz Volker; Sætran, Lars Roar (Journal article; Peer reviewed, 2017)
      Nowadays, not only the size of single wind turbines but also the size of wind farms is increasing. Understanding the interaction between the turbines and especially the wakes formed behind them are getting more important ...
    • Lidars for Wind Tunnels - an IRPWind Joint Experiment Project 

      Sjöholm, Mikael; Vignaroli, Andrea; Angelou, Nikolas; Nielsen, Morten Busk; Mann, Jakob; Mikkelsen, Torben; Bolstad, Hans Christian; Merz, Karl Otto; Sætran, Lars Roar; Mühle, Franz Volker; Tiihonen, Mikko; Lethomäki, Ville (Journal article; Peer reviewed, 2017)
      Measurement campaigns with continuous-wave Doppler Lidars (Light detection and ranging) developed at DTU Wind Energy in Denmark were performed in two very different wind tunnels. Firstly, a measurement campaign in a small ...
    • Validation of the real-time-response ProCap measurement system for full field wake scans behind a yawed model-scale wind turbine 

      Bartl, Jan Michael Simon; Müller, Andreas; Landolt, Andrin; Mühle, Franz Volker; Vatn, Mari; Oggiano, Luca; Sætran, Lars Roar (Journal article; Peer reviewed, 2018)
      For an accurate prediction of the complex flow conditions in wind farms, model scale wake flow measurements represent important references in well-defined boundary conditions. State-of-the art flow measurement techniques ...
    • Vortex interaction in the wake of a two- and three-bladed wind turbine 

      Bartl, Jan Michael Simon; Hansen, Thomas; Kuhn, Wolf Ludwig; Mühle, Franz Volker; Sætran, Lars Roar (Peer reviewed; Journal article, 2020)
      The vortex interaction in the wake behind a two- and three-bladed model scale wind turbine is investigated. The two rotors have equal solidity, and produce similar power and thrust at the design tip speed ratio. Phase-averaged ...
    • Wind tunnel experiments on wind turbine wakes in yaw: effects of inflow turbulence and shear 

      Bartl, Jan Michael Simon; Mühle, Franz Volker; Schottler, Jannik; Sætran, Lars Roar; Peinke, Joachim; Adaramola, Muyiwa S.; Holling, Micheal (Journal article; Peer reviewed, 2018)
      The wake characteristics behind a yawed model wind turbine exposed to different customized inflow conditions are investigated. Laser Doppler anemometry is used to measure the wake flow in two planes at x∕D = 3 and x∕D = 6, ...
    • Wind tunnel experiments on wind turbine wakes in yaw: redefining the wake width 

      Schottler, Jannik; Bartl, Jan Michael Simon; Mühle, Franz Volker; Sætran, Lars Roar; Peinke, Joachim; Hölling, Michael (Journal article; Peer reviewed, 2018)
      This paper presents an investigation of wakes behind model wind turbines, including cases of yaw misalignment. Two different turbines were used and their wakes are compared, isolating effects of boundary conditions and ...
    • Wind tunnel study on power output and yaw moments for two yaw-controlled model wind turbines 

      Bartl, Jan Michael Simon; Mühle, Franz Volker; Sætran, Lars Roar (Journal article; Peer reviewed, 2018)
      In this experimental wind tunnel study the effects of intentional yaw misalignment on the power production and loads of a downstream turbine are investigated for full and partial wake overlap. Power, thrust force and yaw ...