dear @Jason.Jonkman ，
I have another question about ExtPtfm.I use the suggestive parameters as input.But the results seen very strange. I calculate 2 models one is using ExtPtfm and another is default settings.
The results about acceleration seen right because the values are different,But for displacement ,the displacement about 2 models is very similar.
the displacement
Dear @Jack.Hardy,
Regarding the tower properties, each row in the Table defines the cross-sectional mass and stiffness properties at the corresponding height. For the definition of TMassDen, TwFAStif, and TwSSStif, see there definition in Table 9 of the old FAST v6 User’s Guide: https://openfast.readthedocs.io/en/main/_downloads/d8bd014121d6505cb25cf49bee5eaa80/Old_FAST6_UsersGuide.pdf.
Regarding your ExtPtfm results, I’m not sure I understand your question. What do you mean by default settings? (I’m not sure what you are comparing to.) Neither am I sure what your actual question is? Regarding the data you share, it would help to share plots rather than tables of data.
Best regards,
Dear @Jason.Jonkman ,
I mean the one model i using ExtPtfm , another is not. But the results about the displacement of tower-top seen exactly similar. I don’t know what the problem is?
I draw the curve about them.
Dear @Jason.Jonkman ,
I’m trying to plot the campbell of the 5MW land turbine. I using the ‘runcampbell.m’ in matlab ,but it’s wrong and the statement is that
Dear @Jack.Hardy,
Thanks for clarifying regarding ExtPtfm, but I’m still not sure what your actual question is.
Regarding runCampbell.m, I’m not sure why you are receiving this error. But as an alternative to the MATLAB Toolbox, I would recommend trying out our newly released Automated Campbell Diagram Code (ACDC) to generate Campbell diagrams from OpenFAST: GitHub - OpenFAST/acdc: ACDC: Automated Campbell Diagram Code.
Best regards,
Dear @Jason.Jonkman ,
I think the wind turbine tower-top will have large displacement under seismic load ,But in my model which i using ExtPtfm is not.As the figure see,the curve about 2 conditions are similar,it means that the seisimic load is no impact for the displacement of tower-top.I don’t know why? maybe the tower is too soft?
Best regards.
Dear @Jack.Hardy,
Can you clarify what you are plotting? I thought ExtPtfm-Dxt and Dxt were the platform displacements from two different solvers (likewise for Dyt). Are you saying that these are actually the tower-top displacements and that the "ExtPtfm-Dxt solution is with seismic excitation and the “Dxt” solution is without seismic excitation? If so, what is the platform (seismic) displacement you are seeing for the ExtPtfm solution?
Best regards,
Dear @Jason.Jonkman ,
I follow your question and plot the displacement .
Dear @Jack.Hardy,
The two versions of PtfmTDxt you share are quite different, one with a magnitude of 0.7 m and the other with a magnitude of 0.0025 m. Which one corresponds to the tower-top displacements you shared earlier? The smaller magnitude will likely not have much effect on the tower displacement.
Best regards,
Dear @Jason.Jonkman ,
In fact, the curve i remake is using “EL centro” ,But i encounter error.So the curve maybe wrong.
The error follows:
OpenFAST
Copyright (C) 2024 National Renewable Energy Laboratory
Copyright (C) 2024 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.
OpenFAST-v3.5.3
Compile Info:
OpenFAST input file heading:
FAST Certification Test #18: NREL 5.0 MW Baseline Wind Turbine (Onshore)
Running ElastoDyn.
Nodal outputs section of ElastoDyn input file not found or improperly formatted.
Running AeroDyn.
AD15 Nodal Outputs: Nodal output section of AeroDyn input file not found or improperly formatted.
Skipping nodal outputs.
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 3)
Running InflowWind.
Reading a 31x31 grid (145 m wide, 17.5 m to 162.5 m above ground) with a characteristic wind
speed of 12 m/s. This full-field file was generated by TurbSim (from OpenFAST-v3.5.3) on
13-Oct-2024 at 10:45:28.
Processed 12000 time steps of 20-Hz grid-field data (period of 600 seconds).
Running ExtPtfm_MCKF.
Running ServoDyn.
Running ServoDyn Interface for Bladed Controllers (using Intel Visual Fortran for Windows).
Using legacy Bladed DLL interface.
Time: 80 of 600 seconds. Estimated final completion at 11:24:47.
FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD_CalcOutput:RotCalcOutput:BEMT_CalcOut
put(node 5, blade 1):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 18, blade 2):UA_CalcOutput:Mach number exceeds 0.3. Theory is invalid. This warning will
not be repeated though the condition may persist.
Warning: SkewedWakeCorrection encountered a large value of chi (94.461 deg), so the yaw
correction will be limited. This warning will not be repeated though the condition may persist.
See the AD15 chi output channels, and consider turning off the Pitt/Peters skew model (set
SkewMod=1) if this condition persists.
FAST_Solution:FAST_AdvanceStates:ED_ABM4:ED_CalcContStateDeriv:SetCoordSy:Small angle assumption
violated in SUBROUTINE SmllRotTrans() due to a large blade deflection (ElastoDyn SetCoordSy). The
solution may be inaccurate. Simulation continuing, but future warnings from SmllRotTrans() will
be suppressed.
Additional debugging message from SUBROUTINE SmllRotTrans(): 83.862 s
Total Real Time: 2.9171 minutes
Total CPU Time: 2.8328 minutes
Simulation CPU Time: 2.8307 minutes
Simulated Time: 10 minutes
Time Ratio (Sim/CPU): 3.5327
OpenFAST terminated normally.
I don’t know why?maybe the Extptfm input is to strong and cause the blade have large deg.
Best regards.
Dear @Jack.Hardy,
Which of the two cases have all of these warnings–the case with small platform displacement or large platform displacement? I’m not understanding what your real issue is. As with any debugging, I would suggest simplifying the model and building complexity in steps.
Best regards,
Dear @Jason.Jonkman ,
It’s not the curves about last 2 times. The seismic data i making it wrong in last 2 times.So i check the input and plot the curve. As you seen,these warnings occur during this time.The curve as follows:
Dear @Jack.Hardy,
You’ve shared different things in different posts and I’m not sure what matches with what. Please start fresh, explain your model set up and the results you are obtaining, summarize your concern with the results, and ask your question.
Best regards,
Dear @Jason.Jonkman ，
Sorry to so many times to change.I using the ExtPtfm in “5MW_Land_DLL_WTurb” test files.I only define the direction surge platform motion and trun off other freedoms in ElastDyn.Then when i run the openfast,these warnings are appearing:
OpenFAST
Copyright (C) 2024 National Renewable Energy Laboratory
Copyright (C) 2024 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.
OpenFAST-v3.5.3
Compile Info:
OpenFAST input file heading:
FAST Certification Test #18: NREL 5.0 MW Baseline Wind Turbine (Onshore)
Running ElastoDyn.
Nodal outputs section of ElastoDyn input file not found or improperly formatted.
Running AeroDyn.
AD15 Nodal Outputs: Nodal output section of AeroDyn input file not found or improperly formatted.
Skipping nodal outputs.
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 1)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 2)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 1, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 2, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 3, blade 3)
Warning: Turning off Unsteady Aerodynamics because polar has constant data. (node 4, blade 3)
Running InflowWind.
Reading a 31x31 grid (145 m wide, 17.5 m to 162.5 m above ground) with a characteristic wind
speed of 12 m/s. This full-field file was generated by TurbSim (from OpenFAST-v3.5.3) on
13-Oct-2024 at 10:45:28.
Processed 12000 time steps of 20-Hz grid-field data (period of 600 seconds).
Running ExtPtfm_MCKF.
Running ServoDyn.
Running ServoDyn Interface for Bladed Controllers (using Intel Visual Fortran for Windows).
Using legacy Bladed DLL interface.
Time: 80 of 600 seconds. Estimated final completion at 11:24:47.
FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD_CalcOutput:RotCalcOutput:BEMT_CalcOut
put(node 5, blade 1):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 18, blade 2):UA_CalcOutput:Mach number exceeds 0.3. Theory is invalid. This warning will
not be repeated though the condition may persist.
Warning: SkewedWakeCorrection encountered a large value of chi (94.461 deg), so the yaw
correction will be limited. This warning will not be repeated though the condition may persist.
See the AD15 chi output channels, and consider turning off the Pitt/Peters skew model (set
SkewMod=1) if this condition persists.
FAST_Solution:FAST_AdvanceStates:ED_ABM4:ED_CalcContStateDeriv:SetCoordSy:Small angle assumption
violated in SUBROUTINE SmllRotTrans() due to a large blade deflection (ElastoDyn SetCoordSy). The
solution may be inaccurate. Simulation continuing, but future warnings from SmllRotTrans() will
be suppressed.
Additional debugging message from SUBROUTINE SmllRotTrans(): 83.862 s
Total Real Time: 2.9171 minutes
Total CPU Time: 2.8328 minutes
Simulation CPU Time: 2.8307 minutes
Simulated Time: 10 minutes
Time Ratio (Sim/CPU): 3.5327
OpenFAST terminated normally.
And the output “PtfmDxt” is follows:
I mean other platform freedoms are closed in ElastDyn.
Dear @Jack.Hardy
The warnings that appear after 80-s into the simulation (“Temporarily turning off UA…”; “Mach number exceeds 0.3…”, “SkewedWakeCorrection encountered a large value of chi…”, “Small angle assumption violated…”) all appear to be driven by your seismic excitation in the surge direction. These are likely caused by the rapid change in displacement, velocity, and acceleration. That said, the PtfmDxt time series you shared seems odd to me; why is displacement ramping up to 2.5 m until about 84 s, then snapping back to zero?
Best regards,
Dear @Jason.Jonkman ，
My seismic excitation is over at about 84s, But the platform has damping so when seismic excitation over , the platform will be free vibration and the platform displacement decrease because of the exist of damping.
This is my anlysis,i don’t know if you think so?
Best regards.
Dear @Jack.Hardy,
I don’t understand why there appears to be a slow ramp up until about 84 s. I would expect the platform displacement to be zero until the seismic excitation starts and then return after the excitation ends.
Best regards,
Dear @Jason.Jonkman ，
In fact,the seismic excitation start at 30s,over at 84s.
is the curve right?
Best regards.
