Journal article · Conference paper
Modelling lidar volume-averaging and its significance to wind turbine wake measurements: Paper
Lidar velocity measurements need to be interpreted differently than conventional in-situ readings. A commonly ignored factor is “volume-averaging”, which refers to lidars not sampling in a single, distinct point but along its entire beam length. However, especially in regions with large velocity gradients, like the rotor wake, can it be detrimental.
Hence, an efficient algorithm mimicking lidar flow sampling is presented, which considers both pulsed and continous-wave lidar weighting functions. The flow-field around a 2.3 MW turbine is simulated using Detached Eddy Simulation in combination with an actuator line to test the algorithm and investigate the potential impact of volume-averaging.
Even with very few points discretising the lidar beam is volume-averaging captured accurately. The difference in a lidar compared to a point measurement is greatest at the wake edges and increases from 30% one rotor diameter (D) downstream of the rotor to 60% at 3D.
| Language: | English |
|---|---|
| Publisher: | IOP Publishing |
| Year: | 2017 |
| Pages: | 012014 |
| Proceedings: | Wake Conference 2017 |
| Series: | Journal of Physics: Conference Series |
| ISSN: | 17426596 and 17426588 |
| Types: | Journal article and Conference paper |
| DOI: | 10.1088/1742-6596/854/1/012014 |
| ORCIDs: | Meyer Forsting, Alexander Raul and Borraccino, Antoine |
Applied fluid mechanics CW radar Fluid mechanics and aerodynamics (mechanical engineering) General fluid dynamics theory, simulation and other computational methods LIDAR velocity measurement LIDAR volume-averaging modelling Measurement Mechanical components Optical radar Power and plant engineering (mechanical engineering) Wakes Wind power plants continous-wave lidar weighting functions detached eddy simulation flow simulation lidar flow sampling optical radar power 2.3 MW pulsed lidar weighting functions rotor diameter rotors (mechanical) velocity measurement wakes wind turbine wake measurement wind turbines
