Abstract
In this paper, the impact of atmospheric stability on a wind turbine wake is studied experimentally and numerically.
The experimental approach is based on full-scale (nacelle based) pulsed lidar measurements of the wake flow field of a
stall-regulated 500 kW turbine at the DTU Wind Energy, Risø campus test site. Wake measurements are averaged within a
mean wind speed bin of 1 m s1 and classified according to atmospheric stability using three different metrics: the Obukhov
length, the Bulk–Richardson number and the Froude number. Three test cases are subsequently defined covering various
atmospheric conditions. Simulations are carried out using large eddy simulation and actuator disk rotor modeling. The
turbulence properties of the incoming wind are adapted to the thermal stratification using a newly developed spectral
tensor model that includes buoyancy effects. Discrepancies are discussed, as basis for future model development and
improvement. Finally, the impact of atmospheric stability on large-scale and small-scale wake flow characteristics is
presently investigated. Copyright © 2015 John Wiley & Sons, Ltd.
| Original language | English |
|---|---|
| Journal | Wind Energy |
| Volume | 19 |
| Issue number | 10 |
| Pages (from-to) | 1785–1805 |
| Number of pages | 21 |
| ISSN | 1095-4244 |
| DOIs | |
| Publication status | Published - 2016 |
Keywords
- Atmospheric stability
- Wake meandering
- Large eddy simulation
- Turbulence
- Lidar