Wind Energy at Earth Sciences Associate Professor Stefan Ivanell Director Wind Energy UU and KTH Wind Centre
Outlook About Wind Energy An overview of research activities Wake studies
Wind Energy Andrew Barney Project assistant Christian Lewander Guest Lecturer Fan Zou Lecturer Stefan Ivanell Director, Wind Energy, Associate Professor Marita Engberg Ekman Coordinator, Energy Technology. Karl Nilsson PhD Student Liselotte Aldén Lecturer Nikolaos Simisisroglou Industrial PhD Student WindSim In close collaboration with the wind energy group at Dept of Earth Sciences, located in Uppsala. Hans Bergström, Researcher Matthias Mohr, Researcher Conny Larsson, Associate Professor Gunilla Britse Lecturer Heracles Polatides Associate Professor Jens Nørkær Sørensen Guest Professor. Ola Eriksson Lecturer, PhD Student Sanna Mels Lecturer, PhD Student Simon-Philippe Breton Associate Professor Johan Arnqvist, PhD student Olof Öhlund, PhD student Petra Thosson, PhD student Nina Svensson, PhD student
Education at 15 years background on distance education. Students from all over the world. About 120 students per year, campus+distance (full time student equivalents) One year master of science; Wind Power project Management, on campus. Bachelor of science in energy technology with focus on wind power project development (90 ETCS), on distance. (needs to be combined with additional 90 ETCS) Collaboration with vocational training centres, a number of theoretical courses, about 200 students/year.
EAWE European Academy for Wind Energy Uppsala University Swedish Node and represents Sweden in the board Network of largest academic institutions in the wind power area. Uppsala University Campus Gotland organized the 9 th PhD seminar, 2013, about 0 PhD students from all over Europe.
Wind Energy Research at and Uppsala Focus on project development and establishment! Multidiciplinary! Teknikgruppen Industry ~ 15 Senior researchers 7 PhD students Nordic Consortium: Optimization and Control of Wind Farms Public authorities
Wake Development: Near wake? Far wake 1. Vortex system formed from circulation 2. Roll-up into center vortex and distinct tip vortices 3. Destabilization of tip vortices : Turbulence intensity : Axial velocity 4. Break down into large-scale turbulence 5. Turbulent mixing 6. Interplay with meandering
Why do we need wake models? To determine performance of wind farms To estimate the life time of turbines in wind farms To operate optimally wind turbines in wind farms To optimize the location of wind turbines Factors influencing the wake: The distance between the turbines The stability of the atmospheric boundary layer
Increasing interest in wind turbine wakes Number of publications on the Web of Knowledge registered on the topic Wind Turbine Wakes
Wake Aerodynamics Full scale tests: Lidar measurements: Tjæreborg NM80, Risø Nordtank 500kW Wake deficits: Sexbierum, Vindeby, Nibe, Alsvik Park perfomance ( power deficits): Horns Rev, Lillgrund, Nysted, NoordZee, Nørrekær Enge Advantage: Disadvantage: No restriction in model numbers Difficult to measure and control
Wake Aerodynamics Wind/Water Tunnel tests: Wakes from a single turbine: NREL, Mexico, NTNU, Delft, ENSAM, IRPHE, Monash, DTU Wind farms: Univ. Minnesota, Johns Hopkins, Univ. Orleans, ECN Advantage: Disadvantage: Easy to measure and control Limitations in Reynolds numbers
Scale requirements in wind energy Turbulent scales: Length scale (m) Velocity scale (m/s) Time scale (s) Airfoil boundary layer 3 2 5 Airfoil 1 2 2 Rotor 2 Cluster 3 2 Wind farm 4 3
Numerical Methods ACD/ACL Actuator Disc KTH Mechanics Actuator Line Lift and drag forces from airfoil data applied along line/disc No need to mesh blade, additional gridpoints in wake
Lillgrund (48 SWT-2.3 MW) KTH Mechanics 4.3 D
Simulation results KTH Mechanics
Derating of first row of turbines KTH Mechanics
KTH Mechanics
Wind Energy Research at and Uppsala Focus on project development and establishment! Multidiciplinary! Industry Public authorities
19 Thanks for the attention! stefan.ivanell@geo.uu.se