Unsteady and Dynamic Co-simulation with Simulink for Turbine with Passive Blade-Pitch

Wind & Water Controls
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I am hoping to run a dynamic simulation which models unsteady aerodynamic effects (e.g. unsteady corrections, dynamic stall, unsteady wake effects) and which accounts for the behaviour of a passive blade-pitch mechanism, based on the loads at the root of each blades, the pitch angle of each blade, and a mechanical model of a passive pitch system, including a non-linear, preloaded spring.

I have a Matlab script to update the rate of pitch angle acceleration for each blade at each time step. The mechanism is too complex to implement as a simple degree-of-freedom in BeamDyn and I do not have the Fortran skills to edit OpenFAST source code and recompile.

I am worried that if I try to implement my passive blade-pitch controller with OpenFAST in a co-simulation with Simulink (where the blade pitch angle is updated at each time step by a Matlab script) that OpenFAST will no longer capture unsteady and dynamic effects.

Is it possible to do this in a co-simulation with Simulink without losing unsteady aerodynamics and dynamic BEMT?

Any help is very much appreciated!

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Dear @Tom.Summers,

Iā€™m not familiar with the details of your passive blade-pitch mechanism, but if you can represent the mechanism as a pitch controller, you could implement the model within one of standard options ServoDyn provides (PCMode = 3 from routine PitchCntrl, 4 = Simulink, and 5 = Bladed-style dynamic library). None of these options require a change to the OpenFAST source code, although PCMode = 3 does requires a recompile of OpenFAST. Nevertheless, with any of these methods, the full dynamic capability of OpenFAST will be available, including dynamic wake and unsteady airfoil aerodynamics.

Best regards,

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