000199197 001__ 199197
000199197 005__ 20180913062522.0
000199197 022__ $$a1996-1073 000199197 02470$$2ISI$$a000330287800020 000199197 0247_$$2doi$$a10.3390/en6105297 000199197 037__$$aARTICLE
000199197 245__ $$aA Numerical Study of the Effects of Wind Direction on Turbine Wakes and Power Losses in a Large Wind Farm 000199197 269__$$a2013
000199197 260__ $$aBasel$$bMdpi Ag$$c2013 000199197 300__$$a17
000199197 336__ $$aJournal Articles 000199197 520__$$aIn this study, large-eddy simulations (LESs) were performed to investigate the effects of changing wind direction on the turbine wakes and associated power losses in the Horns Rev offshore wind farm. In the LES framework, the turbulent subgrid-scale stresses are parameterized using a tuning-free Lagrangian scale-dependent dynamic model, and the turbine-induced forces are computed using a dynamic actuator-disk model with rotation (ADM-R). This dynamic ADM-R couples blade-element theory with a turbine-specific relation between the blade angular velocity and the shaft torque to compute simultaneously turbine angular velocity and power output. A total of 67 simulations were performed for a wide range of wind direction angles. Results from the simulations show a strong impact of wind direction on the spatial distribution of turbine-wake characteristics, such as velocity deficit and turbulence intensity. This can be explained by the fact that changing the wind angle can be viewed as changing the wind farm layout relative to the incoming wind, while keeping the same wind turbine density. Of particular importance is the effect of wind direction on the distance available for the wakes to recover and expand before encountering other downwind turbines (in full-wake or partial-wake interactions), which affects the power losses from those turbines. As a result, even small changes in wind direction angle can have strong impacts on the total wind farm power output. For example, a change in wind direction of just 10 degrees from the worst-case full-wake condition is found to increase the total power output by as much as 43%. This has important implications for the design of wind farms and the management of the temporal variability of their power output.
000199197 6531_ $$aactuator-disk model with rotation 000199197 6531_$$aatmospheric boundary layer
000199197 6531_ $$ablade-element theory 000199197 6531_$$aHorns Rev wind farm
000199197 6531_ $$alarge-eddy simulation 000199197 6531_$$apower deficit
000199197 6531_ $$awind direction 000199197 700__$$0243661$$aPorté-Agel, Fernando$$g168244
000199197 700__ $$0243662$$aWu, Yu-Ting$$g199093 000199197 700__$$aChen, Chang-Hung
000199197 773__ $$j6$$k10$$q5297-5313$$tEnergies
000199197 909C0 $$0252260$$pWIRE$$xU12172 000199197 909CO$$ooai:infoscience.tind.io:199197$$particle$$pENAC
000199197 917Z8 $$x133327 000199197 937__$$aEPFL-ARTICLE-199197
000199197 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED 000199197 980__$$aARTICLE