TurbOPark is developed by Ørsted and is loosely based on the model developed by Bastankhah and Porté-Agel but with significant improvements. The main improvement is that it simulates variable mixing with turbulence. Wake-induced turbulence just behind the rotor results in increased mixing and hence wake recovery. However, this wake-induced turbulence dissipates quickly as we move downwind away from the rotor and so the mixing and wake recovery should also fall off with distance. TurbOPark incorporates this behaviour and so can be seen as a step forward compared to other wake models with a single fixed rate of wake recovery. The implementation of TurbOPark in Openwind is based on the code repository shared by Ørsted here. A paper describing the model is available here.
Figure 133: TurbOPark Settings Dialog
The tunable parameter, A, has been set as 0.04 by Ørsted and is intended to model long distance wakes. However, such a small value can lead to very narrow wakes and when used without post-processing to smooth this behaviour, can lead to sharp differences in wake loss with very small changes in direction. Openwind does not offer smoothing as this is not included in the online code repository. Increasing A can smooth the wake behaviour but at the expense of the long-range wake behaviour.