Supervisors: Supervisor: Senior Scientist Niels Troldborg, DTU Vindenergi, Senior Scientist Andreas Bechmann, DTU Vindenergi, Co-supervisor: Senior Scientist Pierre-Elouan Réthoré, DTU Vindenergi
Eksterne eksaminatorer: Professor Jens Nørkær Sørensen, DTU Vindenergi, Professor Rebecca Barthelmie, Cornell University, Research Group Leader David Schlip, University of Stuttgart
Titel: Modelling Wind Turbine Inflow
Lidars (wind speed measuring lasers) will change the way wind turbines sense the wind. Instead of measuring far away from the turbine, they will measure within one rotor diameter of the turbine. This will enhance the correlation between the measured wind field and the one ultimately interacting with the turbine. It will lower the uncertainty in power curve assessment and allow better individual as well as communal turbine control. Our inflow models are essential to these measurements close to the turbine rotor, as they will offset the measurement uncertainty from rotor effects. We use a multi-fidelity modelling approach in combination with extensive validation through field measurements. We validated of our high fidelity model and have derived a simple engineering model, which can be used for commercial purposes. Furthermore, our findings might channel into future IEC standards on power curve assessment.
A wide bandwidth of methods are used incorporating both models and measurements. In modelling the inflow we deploy approaches spanning various levels of fidelity. Starting from high fidelity computational fluid dynamics with LES and RANS approaches over potential flow methods right down to engineering models. To validate the high-fidelity methods a field measurement campaign with a triple-lidar system (windscanner.dk) was conducted in flat and complex terrain. This novel measurement equipment allowed to capture full velocity vectors upstream of full-scale wind turbines. Furthermore field measurements with commercial nacelle-mounted lidars allow to test the engineering model.
We have provided the first comprehensive validation of a CFD model over the entire upstream flow region of a full-scale wind turbine. This gives us confidence in our modelling approach and allows our industry partners to endorse it. Our engineering model should allow industry to use nacelle-mounted lidars for power curve assessment and might allow lidar-based wind turbine control in the future. Furthermore we hope that our work will contribute to a new IEC standard.
Lidars (wind speed measuring lasers) will change the way wind turbines sense the wind. Instead of measuring far away from the turbine, they will measure within one rotor diameter of the turbine. This will enhance the correlation between the measured wind field and the one ultimately interacting with the turbine. It will lower the uncertainty in power curve assessment and allow better individual as well as communal turbine control. Our inflow models are essential to these measurements close to the turbine rotor, as they will offset the measurement uncertainty from rotor effects. We use a multi-fidelity modelling approach in combination with extensive validation through field measurements. We validated of our high fidelity model and have derived a simple engineering model, which can be used for commercial purposes. Furthermore, our findings might channel into future IEC standards on power curve assessment.
We have provided the first comprehensive validation of a CFD model over the entire upstream flow region of a full-scale wind turbine. This gives us confidence in our modelling approach and allows our industry partners to endorse it. Our engineering model should allow industry to use nacelle-mounted lidars for power curve assessment and might allow lidar-based wind turbine control in the future. Furthermore we hope that our work will contribute to a new IEC standard.