Bug report

[lin990316]

Hello, I encountered this warning when using openfast to calculate the IEA-15MW model, I have seen a similar consultation on the website, in which the solution is to modify the format of the .DLL file in the servodyn file, I followed this and then openfast can perform the calculations, but still can not avoid such a warning, may I ask what should be done to solve the problem?

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OpenFAST

Copyright (C) 2023 National Renewable Energy Laboratory Copyright (C) 2023 Envision Energy USA LTD

This program is licensed under Apache License Version 2.0 and comes with ABSOLUTELY NO WARRANTY. See the "LICENSE" file distributed with this software for details.

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OpenFAST-Unversioned from e8ec53f9c7f9d3f6a13bfb61dba12a0ca04d8a2f Compile Info:

• Compiler: Intel(R) Fortran Compiler 2021
• Architecture: 64 bit
• Precision: single
• OpenMP: No
• Date: Feb 08 2023
• Time: 00:53:58 Execution Info:
• Date: 07/14/2023
• Time: 13:30:57+0800

OpenFAST input file heading: IEA 15 MW offshore reference model on UMaine VolturnUS-S semi-submersible floating platform

Running ElastoDyn. Running AeroDyn. Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 1) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 1) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 4, blade 1) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 5, blade 1) Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 2) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 2) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 4, blade 2) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 5, blade 2) Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 3) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 3) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 4, blade 3) Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 5, blade 3) Running InflowWind. Running HydroDyn. WARNING: The requested output channel is invalid: WavesF1xi WARNING: The requested output channel is invalid: WavesF1zi WARNING: The requested output channel is invalid: WavesM1yi WARNING: The requested output channel is invalid: WavesF2xi WARNING: The requested output channel is invalid: WavesF2zi WARNING: The requested output channel is invalid: WavesM2yi WARNING: The requested output channel is invalid: WavesF2xi WARNING: The requested output channel is invalid: WavesF2yi WARNING: The requested output channel is invalid: WavesF2zi WARNING: The requested output channel is invalid: WavesM2xi WARNING: The requested output channel is invalid: WavesM2yi WARNING: The requested output channel is invalid: WavesM2zi Generating incident wave kinematics and current time history. Calculating second order difference frequency wave kinematics. Calculating second order sum frequency wave kinematics. Reading in WAMIT output with root name ".\HydroData/IEA-15-240-RWT-UMaineSemi". Computing radiation impulse response functions and wave diffraction forces. Calculating second order difference-frequency force using the full quadratic transfer function. Running MoorDyn (v2.0.0, 2022-12-08). This is MoorDyn v2, with significant input file changes from v1. Copyright: (C) 2022 National Renewable Energy Laboratory, (C) 2019 Matt Hall Parsing MoorDyn input file: .\IEA-15-240-RWT-UMaineSemi_MoorDyn.dat Warning: invalid output specifier FX. Must start with L, C, R, or B Warning: invalid output specifier FY. Must start with L, C, R, or B Warning: invalid output specifier FZ. Must start with L, C, R, or B Created mooring system: 3 lines, 6 points, 0 rods, 0 bodies. Finalizing initial conditions using dynamic relaxation. t=60 FairTen 1: 2.43287E+06, 2.44526E+06, 2.43537E+06 Fairlead tensions did not converge within TMaxIC=60 seconds. MoorDyn initialization completed. Running ServoDyn. Running ServoDyn Interface for Bladed Controllers (using Intel Visual Fortran for Windows). Using legacy Bladed DLL interface.

FAST_InitializeAll:HydroDyn_Init:HydroDynInput_ProcessInitData: A requested output channel is invalid

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Running ROSCO-v2.7.0 A wind turbine controller framework for public use in the scientific field Developed in collaboration: National Renewable Energy Laboratory Delft University of Technology, The Netherlands

Generator speed: 7.6 RPM, Pitch angle: 1.0 deg, Power: 0.0 kW, Est. wind Speed: 10.0 m/s

FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD_CalcOutput:RotCalcOutput:BEMT_CalcOut put(node 3, blade 3):UA_CalcOutput:UA_BlendSteady:Temporarily turning off UA due to high angle of attack or low relative velocity. This warning will not be repeated though the condition may persist.

FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD_CalcOutput:RotCalcOutput:BEMT_CalcOut put(node 50, blade 2):UA_CalcOutput:Mach number exceeds 0.3. Theory is invalid. This warning will not be repeated though the condition may persist. Generator speed: 5.5 RPM, Pitch angle: 4.5 deg, Power: 10046.8 kW, Est. wind Speed: 8.6 m/s

Total Real Time: 6.459 seconds Total CPU Time: 6.3281 seconds Simulation CPU Time: 2.125 seconds Simulated Time: 10 seconds Time Ratio (Sim/CPU): 4.7059

OpenFAST terminated normally.

[jjonkman]

Dear @lin990316,

It looks like your simulation completed normally, without error. You received several warnings; which one are you concerned with?

Best regards,

[lin990316]

Warning when reading AeroDyn I've seen answers to similar questions, it seems it has no effect on the calculations right? My main concern at the moment is why these two types of warnings appear: "WARNING: The requested output channel is invalid: WavesF1xi" "Warning: invalid output specifier FX. Must start with L, C, R, or B" At the same time I have several invalid columns in my calculation output .out file,I don't know how I can fix the problem to avoid such warnings, I would appreciate your answer, thank you very much!

[ebranlard]

It seems like you have channel names in your "Outlist" of HydroDyn and MoorDyn that are invalid.

The valid channel names are listed in the OutListParameters.xlsx file located in the folder docs/OtherSupporting/ of the OpenFAST repository. For instance, for the main branch: https://github.com/OpenFAST/openfast/blob/main/docs/OtherSupporting/OutListParameters.xlsx.

We do change the channel names from time to time, so it's important to use a file that is within a git tag that is the same as your OpenFAST version.

For MoorDyn, you might have to look at its documentation. Maybe @mattEhall can recognize channels that have been renamed based on your error message.

[lin990316]

Fine, thank you very much, I'll try to follow your instructions to fix it, Best regards,