Dear Giuseppe,
I see a couple problems with your approach:
*The OC3-Hywind model included a few customizations to the source code to more accurately model the OC3-Hywind system. You can read about these customizations in the following forum topic: Additional linear hydrodynamic damping in OC3 Hywind. These customizations are included in the special executable supplied with the OC3-Hywind model, but we have not built a FAST S-function for Simulink with these customizations. For accurate simulations of the OC3-Hywind model within Simulink, I suggest you recompile the FAST S-Function with these customizations.
*The controller for the OC3-Hywind model was implemented as a GH Bladed DLL. The DLL interface was included in the special executable mentioned above, but we have not built a FAST S-function for Simulink with this interface. So, you are probably not getting what you want when you toggle to “user-defined routine” within Simulink.
I’m not exactly sure what is causing the model to move enough to exceed the boundaries of the turbulence grid, but you can avoid this error by using steady winds in place of turbulent winds. Steady winds can be specified using AeroDyn’s so-called “hub-height” wind data files.
Best regards,