Originally Posted by
biscuit74
As for the estimate of turbulence impacts dissipating within 5-8 time rotor diameter, I'd really like to see the link to that, or some citation, please
There you go, Sir, please let us know what you think.
https://www.liverpool.ac.uk/media/li...ine_report.pdf
As in many fields of science, this is the current best thinking, but there is always a possibility to refine and improve the models, the LIDAR wind speed measurements etc.
I personally find it challenging the separate turbulence caused by wind turbine blades and other turbulence caused by terrain, or low-level wind shear near the ground due to tree-lines and buildings.
Some interesting parts of the study, highlighted by me:
The statistical LIDAR data indicated that for this particular wind turbine the wake mean velocities recovered to the free stream speed at a position about five rotor diameters downstream. The LIDAR measurements were compared with the results of a full CFD simulation conducted for the MEXICO wind turbine with a similar tip speed ratio, and also compared with the velocity deficit wake models. In general, reasonable agreement was found.
The WTN250 wake induced velocity fields generated by the Kocurek wake vortex model, were integrated into an aircraft flight dynamics model based on a GA configuration to simulate the wind turbine wake encounter scenario of a light aircraft approaching an airport. Piloted flight simulations were carried out to study the severity of this type of wake encounter. The flight simulation results suggest that the WTN250 wind turbine wake mainly generated yaw disturbances on the encountering aircraft and caused a yaw angle deviation less than 10 deg.