Effect of different Rotor-average models with NOJDeficit Model
Hi, We designed a layout with three turbines. All three turbines are placed in a horizontal row (wt_x is different but wt_y is constant for all the three turbines) and wind speed is specified from eastern (wd=90degrees) direction only. We calculated the wake loss with the same NOJDeficit model but with different Rotor-average models. With NOJDeficit model, the deficit is expected to not vary over the rotor. Due to this, all rotor-average models should result in same wake loss or effective wind speeds at the turbines. However, we noticed a difference with the layout in which the distance between adjacent turbines is equal to three rotor diameters. For example, effective wind speed at the most waked turbine (most downstream) using 'RotorCenter' is 6.5m/s while effective wind speed with 'GridRotorAvg with x = y = np.array([-.6, 0,.6])' is 7.1m/s. We did not expect to see this. However, when we use 'GridRotorAvg' with x = y = np.array([-.01, 0,.01]), the effective wind speed is matching with the effective wind speed from 'RotorCenter'. This means that something unexpected is happening when we consider points away from the rotor center for rotor averaging. We saw this behavior with other Rotor-average models as well. We have attached our python note book with this issue. Can you please check and let us know if we did anything wrong at our end or if there is any correction needed in the pywake code?
Regards, Ravi NOJ_with_different_Rotor_Avg_Models.ipynb