Divergence issue with FastFarm.OpenMP (AeroDisk pitch out of bounds error)

[stefii03]

Good morning,

I am writing to seek your assistance regarding an issue I encountered while simulating a wind farm. I ran the simulation using FastFarm.OpenMP, but the software aborted the execution.

The error reported indicated that the AeroDisk module received a pitch value outside of its valid input range. Specifically, the software threw the following error message:

T1:FARM_UpdateStates:FWrap_Increment:FAST_Solution:FAST_UpdateStates:Solver_Step:FAST_CalcOutput:ADsk_CalcOutput:ADskTableInterp: Blade pitch value of 0.2622 is outside bounds of aero table [0:0.2618]

This behavior seemed anomalous to me: the table bounds reported in the error (0.2618 rad) correspond to a maximum pitch of 15°, and I would not expect the simulation to reach such high values.

To troubleshoot, I ran the same simulation using the standard FastFarm executable (without OpenMP). In this case, there were no issues: the simulation completed successfully, and the maximum pitch value recorded was only 1°.

Given the results of this comparison, my hypothesis is that the simulation is diverging when using FastFarm.OpenMP.

Could you please advise on how to resolve this issue or point me toward any specific parameters I should check?

Thank you in advance for your time and support.

Best regards,

Stefania and Matteo from Politecnico di Milano :)

[andrew-platt]

Thank you for reporting this. We are currently investigating some unexpected behavior in FAST.Farm with OpenMP.

A few questions:

• are your compiling this or using the provided Windows executables?
• how many turbines in the simulation?
• can you attach your main FAST.Farm input file?

Possibly related:

• FAST.Farm parallel run failure at 11.4 m/s with two turbines – possible OMP solver issue #3272
• Turbsim_OpenMp issue #3273

[stefii03]

Thank you for getting back to me so quickly!

To answer your questions:

I am using the provided Windows executables.

The wind farm in the simulation consists of 4 turbines.

This is the FAST.Farm input file:
FAST.Farm_input.txt

Please let me know if you need any additional files or further information to help investigate the issue.

Best regards,

Stefania and Matteo