Using TurbSim issue

[iosaaaa]

Hi, I'm trying to use TurbSim to generate a .bts file to simulate a storm on openfast. Initially, I ran TurbSim, with a small grid size of NumGrid_Z = 13 and NumGrid_Z = 13 and it worked, producing a new .bts file. When i ran OpenFAST, i got an error, which I think was because my grid size in inflow wind file did not match my grid size in my turbsim.inp file.

I then changed my turbsim.inp file to NumGrid_Z = 31 and NumGrid_Z = 31 so as to match that of my inflow wind file. Now with this bigger grid size, turbsim is taking an extremely long time to run! I have been waiting for 3 hours now and it still has not completed. I'm wondering is this normal, and is there anything I can change in my files to speed up the process? I'll attach my turbsim.inp and inflow wind input file below in case anything is sticking out to you. Thanks again!

Below is my TurbSim.inp file:

---------Runtime Options-----------------------------------
2318573 RandSeed1 - First random seed (-2147483648 to 2147483647)
RANLUX RandSeed2 - Second random seed (-2147483648 to 2147483647) for intrinsic pRNG, or an alternative pRNG: "RanLux" or "RNSNLW"
False WrBHHTP - Output hub-height turbulence parameters in binary form? (Generates RootName.bin)
False WrFHHTP - Output hub-height turbulence parameters in formatted form? (Generates RootName.dat)
False WrADHH - Output hub-height time-series data in AeroDyn form? (Generates RootName.hh)
True WrADFF - Output full-field time-series data in TurbSim/AeroDyn form? (Generates Rootname.bts)
False WrBLFF - Output full-field time-series data in BLADED/AeroDyn form? (Generates RootName.wnd)
False WrADTWR - Output tower time-series data? (Generates RootName.twr)
False WrFMTFF - Output full-field time-series data in formatted (readable) form? (Generates RootName.u, RootName.v, RootName.w)
True WrACT - Output coherent turbulence time steps in AeroDyn form? (Generates RootName.cts)
True Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)
0 ScaleIEC - Scale IEC turbulence models to exact target standard deviation? [0=no additional scaling; 1=use hub scale uniformly; 2=use individual scales]

--------Turbine/Model Specifications-----------------------
31 NumGrid_Z - Vertical grid-point matrix dimension
31 NumGrid_Y - Horizontal grid-point matrix dimension
0.05 TimeStep - Time step [seconds]
600 AnalysisTime - Length of analysis time series [seconds] (program will add time if necessary: AnalysisTime = MAX(AnalysisTime, UsableTime+GridWidth/MeanHHWS) )
40 UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds)
98 HubHt - Hub height [m] (should be > 0.5GridHeight)
154.0 GridHeight - Grid height [m]
145.0 GridWidth - Grid width [m] (should be >= 2(RotorRadius+ShaftLength))
0 VFlowAng - Vertical mean flow (uptilt) angle [degrees]
0 HFlowAng - Horizontal mean flow (skew) angle [degrees]

--------Meteorological Boundary Conditions-------------------
"IECKAI" TurbModel - Turbulence model ("IECKAI"=Kaimal, "IECVKM"=von Karman, "GP_LLJ", "NWTCUP", "SMOOTH", "WF_UPW", "WF_07D", "WF_14D", or "NONE")
"1-ED3" IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. "1-Ed2") )
"A" IECturbc - IEC turbulence characteristic ("A", "B", "C" or the turbulence intensity in percent) ("KHTEST" option with NWTCUP model, not used for other models)
"NTM" IEC_WindType - IEC turbulence type ("NTM"=normal, "xETM"=extreme turbulence, "xEWM1"=extreme 1-year wind, "xEWM50"=extreme 50-year wind, where x=wind turbine class 1, 2, or 3)
default ETMc - IEC Extreme Turbulence Model "c" parameter [m/s]
default WindProfileType - Wind profile type ("JET","LOG"=logarithmic,"PL"=power law,"IEC"=PL on rotor disk,LOG elsewhere, or "default")
98.0 RefHt - Height of the reference wind speed [m]
30 URef - Mean (total) wind speed at the reference height [m/s] (or "default" for JET wind profile)
default ZJetMax - Jet height [m] (used only for JET wind profile, valid 70-490 m)
default PLExp - Power law exponent [-] (or "default")
default Z0 - Surface roughness length [m] (or "default")

--------Non-IEC Meteorological Boundary Conditions------------
default Latitude - Site latitude [degrees] (or "default")
0.05 RICH_NO - Gradient Richardson number
default UStar - Friction or shear velocity [m/s] (or "default")
default ZI - Mixing layer depth [m] (or "default")
default PC_UW - Hub mean u'w' Reynolds stress (or "default")
default PC_UV - Hub mean u'v' Reynolds stress (or "default")
default PC_VW - Hub mean v'w' Reynolds stress (or "default")
default IncDec1 - u-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default IncDec2 - v-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default IncDec3 - w-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default CohExp - Coherence exponent (or "default")

--------Coherent Turbulence Scaling Parameters-------------------
"M:\coh_events\eventdata" CTEventPath - Name of the path where event data files are located
"Random" CTEventFile - Type of event files ("LES", "DNS", or "RANDOM")
true Randomize - Randomize the disturbance scale and locations? (true/false)
1.0 DistScl - Disturbance scale (ratio of wave height to rotor disk). (Ignored when Randomize = true.)
0.5 CTLy - Fractional location of tower centerline from right (looking downwind) to left side of the dataset. (Ignored when Randomize = true.)
0.5 CTLz - Fractional location of hub height from the bottom of the dataset. (Ignored when Randomize = true.)
30.0 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]

And below is my inflow wind input file:

------- InflowWind INPUT FILE -------------------------------------------------------------------------
12 m/s turbulent winds on 31x31 FF grid and tower for FAST CertTests #18, #19, #21, #22, #23, and #24

False Echo - Echo input data to .ech (flag)
3 WindType - switch for wind file type (1=steady; 2=uniform; 3=binary TurbSim FF; 4=binary Bladed-style FF; 5=HAWC format; 6=User defined; 7=native Bladed FF)
0 PropagationDir - Direction of wind propagation (meteorological rotation from aligned with X (positive rotates towards -Y) -- degrees) (not used for native Bladed format WindType=7)
0 VFlowAng - Upflow angle (degrees) (not used for native Bladed format WindType=7)
False VelInterpCubic - Use cubic interpolation for velocity in time (false=linear, true=cubic) [Used with WindType=2,3,4,5,7]
1 NWindVel - Number of points to output the wind velocity (0 to 9)
0 WindVxiList - List of coordinates in the inertial X direction (m)
0 WindVyiList - List of coordinates in the inertial Y direction (m)
90 WindVziList - List of coordinates in the inertial Z direction (m)
================== Parameters for Steady Wind Conditions [used only for WindType = 1] =========================
30 HWindSpeed - Horizontal wind speed (m/s)
98 RefHt - Reference height for horizontal wind speed (m)
0.2 PLExp - Power law exponent (-)
================== Parameters for Uniform wind file [used only for WindType = 2] ============================
"unused" Filename_Uni - Filename of time series data for uniform wind field. (-)
90 RefHt_Uni - Reference height for horizontal wind speed (m)
125.88 RefLength - Reference length for linear horizontal and vertical sheer (-)
================== Parameters for Binary TurbSim Full-Field files [used only for WindType = 3] ==============
"Wind/TurbSimCARAI.bts" FileName_BTS - Name of the Full field wind file to use (.bts)
================== Parameters for Binary Bladed-style Full-Field files [used only for WindType = 4 or WindType = 7] =========
"unused" FileNameRoot - WindType=4: Rootname of the full-field wind file to use (.wnd, .sum); WindType=7: name of the intermediate file with wind scaling values
False TowerFile - Have tower file (.twr) (flag) ignored when WindType = 7
================== Parameters for HAWC-format binary files [Only used with WindType = 5] =====================
"wasp\Output\basic_5u.bin" FileName_u - name of the file containing the u-component fluctuating wind (.bin)
"wasp\Output\basic_5v.bin" FileName_v - name of the file containing the v-component fluctuating wind (.bin)
"wasp\Output\basic_5w.bin" FileName_w - name of the file containing the w-component fluctuating wind (.bin)
64 nx - number of grids in the x direction (in the 3 files above) (-)
32 ny - number of grids in the y direction (in the 3 files above) (-)
32 nz - number of grids in the z direction (in the 3 files above) (-)
16 dx - distance (in meters) between points in the x direction (m)
3 dy - distance (in meters) between points in the y direction (m)
3 dz - distance (in meters) between points in the z direction (m)
90 RefHt_Hawc - reference height; the height (in meters) of the vertical center of the grid (m)
------------- Scaling parameters for turbulence ---------------------------------------------------------
2 ScaleMethod - Turbulence scaling method [0 = none, 1 = direct scaling, 2 = calculate scaling factor based on a desired standard deviation]
1 SFx - Turbulence scaling factor for the x direction (-) [ScaleMethod=1]
1 SFy - Turbulence scaling factor for the y direction (-) [ScaleMethod=1]
1 SFz - Turbulence scaling factor for the z direction (-) [ScaleMethod=1]
1.2 SigmaFx - Turbulence standard deviation to calculate scaling from in x direction (m/s) [ScaleMethod=2]
0.8 SigmaFy - Turbulence standard deviation to calculate scaling from in y direction (m/s) [ScaleMethod=2]
0.2 SigmaFz - Turbulence standard deviation to calculate scaling from in z direction (m/s) [ScaleMethod=2]
------------- Mean wind profile parameters (added to HAWC-format files) ---------------------------------
12 URef - Mean u-component wind speed at the reference height (m/s)
2 WindProfile - Wind profile type (0=constant;1=logarithmic,2=power law)
0.2 PLExp_Hawc - Power law exponent (-) (used for PL wind profile type only)
0.03 Z0 - Surface roughness length (m) (used for LG wind profile type only)
0 XOffset - Initial offset in +x direction (shift of wind box)
================== LIDAR Parameters ===========================================================================
0 SensorType - Switch for lidar configuration (0 = None, 1 = Single Point Beam(s), 2 = Continuous, 3 = Pulsed)
0 NumPulseGate - Number of lidar measurement gates (used when SensorType = 3)
30 PulseSpacing - Distance between range gates (m) (used when SensorType = 3)
0 NumBeam - Number of lidar measurement beams (0-5)(used when SensorType = 1)
-200 FocalDistanceX - Focal distance co-ordinates of the lidar beam in the x direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
0 FocalDistanceY - Focal distance co-ordinates of the lidar beam in the y direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
0 FocalDistanceZ - Focal distance co-ordinates of the lidar beam in the z direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
0.0 0.0 0.0 RotorApexOffsetPos - Offset of the lidar from hub height (m)
17 URefLid - Reference average wind speed for the lidar[m/s]
0.25 MeasurementInterval - Time between each measurement [s]
False LidRadialVel - TRUE => return radial component, FALSE => return 'x' direction estimate
1 ConsiderHubMotion - Flag whether to consider the hub motion's impact on Lidar measurements
====================== OUTPUT ==================================================
False SumPrint - Print summary data to .IfW.sum (flag)
OutList - The next line(s) contains a list of output parameters. See OutListParameters.xlsx for a listing of available output channels, (-)
"Wind1VelX" X-direction wind velocity at point WindList(1)
"Wind1VelY" Y-direction wind velocity at point WindList(1)
"Wind1VelZ" Z-direction wind velocity at point WindList(1)
END of input file (the word "END" must appear in the first 3 columns of this last OutList line)

And lastly, this is my 90m_12mps_twr.inp file:
---------TurbSim v2.* Input File------------------------
Example file that can be used with simulations for the NREL 5MW Baseline Turbine; note that UsableTime has been decreased in this file so that the file distributed with the FAST CertTest isn't as large
---------Runtime Options-----------------------------------
False Echo - Echo input data to .ech (flag)
13428 RandSeed1 - First random seed (-2147483648 to 2147483647)
"RanLux" RandSeed2 - Second random seed (-2147483648 to 2147483647) for intrinsic pRNG, or an alternative pRNG: "RanLux" or "RNSNLW"
False WrBHHTP - Output hub-height turbulence parameters in binary form? (Generates RootName.bin)
False WrFHHTP - Output hub-height turbulence parameters in formatted form? (Generates RootName.dat)
False WrADHH - Output hub-height time-series data in AeroDyn form? (Generates RootName.hh)
True WrADFF - Output full-field time-series data in TurbSim/AeroDyn form? (Generates RootName.bts)
False WrBLFF - Output full-field time-series data in BLADED/AeroDyn form? (Generates RootName.wnd)
True WrADTWR - Output tower time-series data? (Generates RootName.twr)
False WrHAWCFF - Output full-field time-series data in HAWC form? (Generates RootName-u.bin, RootName-v.bin, RootName-w.bin, RootName.hawc)
False WrFMTFF - Output full-field time-series data in formatted (readable) form? (Generates RootName.u, RootName.v, RootName.w)
False WrACT - Output coherent turbulence time steps in AeroDyn form? (Generates RootName.cts)
0 ScaleIEC - Scale IEC turbulence models to exact target standard deviation? [0=no additional scaling; 1=use hub scale uniformly; 2=use individual scales]

--------Turbine/Model Specifications-----------------------
13 NumGrid_Z - Vertical grid-point matrix dimension
13 NumGrid_Y - Horizontal grid-point matrix dimension
0.05 TimeStep - Time step [seconds]
630 AnalysisTime - Length of analysis time series [seconds] (program will add time if necessary: AnalysisTime = MAX(AnalysisTime, UsableTime+GridWidth/MeanHHWS) )
60 UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds unless UsableTime is "ALL")
98 HubHt - Hub height [m] (should be > 0.5GridHeight)
145 GridHeight - Grid height [m]
145 GridWidth - Grid width [m] (should be >= 2(RotorRadius+ShaftLength))
0 VFlowAng - Vertical mean flow (uptilt) angle [degrees]
0 HFlowAng - Horizontal mean flow (skew) angle [degrees]

--------Meteorological Boundary Conditions-------------------
"IECKAI" TurbModel - Turbulence model ("IECKAI","IECVKM","GP_LLJ","NWTCUP","SMOOTH","WF_UPW","WF_07D","WF_14D","TIDAL","API","USRINP","TIMESR", or "NONE")
"TurbSim_User.spectra" UserFile - Name of the file that contains inputs for user-defined spectra or time series inputs (used only for "USRINP" and "TIMESR" models)
"1-ed3" IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. "1-Ed2") )
"A" IECturbc - IEC turbulence characteristic ("A", "B", "C" or the turbulence intensity in percent) ("KHTEST" option with NWTCUP model, not used for other models)
"NTM" IEC_WindType - IEC turbulence type ("NTM"=normal, "xETM"=extreme turbulence, "xEWM1"=extreme 1-year wind, "xEWM50"=extreme 50-year wind, where x=wind turbine class 1, 2, or 3)
"default" ETMc - IEC Extreme Turbulence Model "c" parameter [m/s]
"PL" WindProfileType - Velocity profile type ("LOG";"PL"=power law;"JET";"H2L"=Log law for TIDAL model;"API";"USR";"TS";"IEC"=PL on rotor disk, LOG elsewhere; or "default")
"TurbSim_User.profiles" ProfileFile - Name of the file that contains input profiles for WindProfileType="USR" and/or TurbModel="USRVKM" [-]
90 RefHt - Height of the reference velocity (URef) [m]
25 URef - Mean (total) velocity at the reference height [m/s] (or "default" for JET velocity profile) [must be 1-hr mean for API model; otherwise is the mean over AnalysisTime seconds]
"default" ZJetMax - Jet height [m] (used only for JET velocity profile, valid 70-490 m)
"default" PLExp - Power law exponent [-] (or "default")
"default" Z0 - Surface roughness length [m] (or "default")

--------Non-IEC Meteorological Boundary Conditions------------
"default" Latitude - Site latitude [degrees] (or "default")
0.05 RICH_NO - Gradient Richardson number [-]
"default" UStar - Friction or shear velocity [m/s] (or "default")
"default" ZI - Mixing layer depth [m] (or "default")
"default" PC_UW - Hub mean u'w' Reynolds stress [m^2/s^2] (or "default" or "none")
"default" PC_UV - Hub mean u'v' Reynolds stress [m^2/s^2] (or "default" or "none")
"default" PC_VW - Hub mean v'w' Reynolds stress [m^2/s^2] (or "default" or "none")

--------Spatial Coherence Parameters----------------------------
"default" SCMod1 - u-component coherence model ("GENERAL","IEC","API","NONE", or "default")
"default" SCMod2 - v-component coherence model ("GENERAL","IEC","NONE", or "default")
"default" SCMod3 - w-component coherence model ("GENERAL","IEC","NONE", or "default")
"default" InCDec1 - u-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
"default" InCDec2 - v-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
"default" InCDec3 - w-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
"default" CohExp - Coherence exponent for general model [-] (or "default")

--------Coherent Turbulence Scaling Parameters-------------------
"M:\coh_events\eventdata" CTEventPath - Name of the path where event data files are located
"Random" CTEventFile - Type of event files ("LES", "DNS", or "RANDOM")
true Randomize - Randomize the disturbance scale and locations? (true/false)
1 DistScl - Disturbance scale [-] (ratio of event dataset height to rotor disk). (Ignored when Randomize = true.)
0.5 CTLy - Fractional location of tower centerline from right [-] (looking downwind) to left side of the dataset. (Ignored when Randomize = true.)
0.5 CTLz - Fractional location of hub height from the bottom of the dataset. [-] (Ignored when Randomize = true.)
10 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]

====================================================
! NOTE: Do not add or remove any lines in this file!

[iosaaaa]

This is the error I'm getting:

MoorDyn initialization completed.

FAST_InitializeAll:HydroDyn_Init:Waves_Init:VariousWaves_Init: The random number generator in use
differs from the original code provided by NREL. This pRNG uses 8 seeds instead of the 2 in the
HydroDyn input file.

Time: 0 of 360 seconds.

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(): 0.65 s

                                                                             Time: 1 of 360 seconds.  Estimated final completion at 19:32:31.                                                                                                Time: 2 of 360 seconds.  Estimated final completion at 19:32:40.                                 

** WARNING: Tower strike. ** This warning will not be repeated though the condition may persist.

FAST_Solution:FAST_AdvanceStates:AD_UpdateStates:SetDisturbedInflow:TwrInfl:Tower strike.

OpenFAST encountered an error at simulation time 2.075 of 360 seconds.
Simulation error level: FATAL ERROR

Aborting OpenFAST.

[iosaaaa]

I am able to get TurbSim running but for some reason I'm still getting that error when running openfast. I have since changed gridwidth and gridheight to 154 in both files, I thought that would fix it but it did not. Anything else I should try?

[bjonkman]

I don't think the issue is your wind file. A tower strike usually indicates that something in your turbine model is unstable or not initialized properly. Have you set the initial blade pitch, rotor speed, surge, and pitch to appropriate values?

[iosaaaa]

Thanks for the response, I looked into my setup and adjusted some values and now I'm getting this error when running OpenFAST:

FAST_Solution0:CalcOutputs_And_SolveForInputs:SolveOption2:SolveOption2c_Inp2AD_SrvD:InflowWind_Ca
lcOutput:CalculateOutput:IfW_FlowField_GetVelAcc:Grid3DField_GetCell: G3D wind array boundaries
violated. Grid too small in Z direction (height (Z=10 m) is below the grid and no tower points
are defined).

I have tried increasing grid size (NumGrid_Z and NumGrid_Y from 15 to 31) but I wonder if I'm looking at the right grid parameters. What part of the inflow wind input file is the z=10 in the error referring to? Appreciate your guidance as always!

[bjonkman]

The number of grid points in TurbSim (NumGrid_Z, NumGrid_Y) will not have an effect on where the grid boundaries are located. In your TurbSim file, it looks like you've set the hub height reference point to be at 98 meters with a grid height and width to be 145 meters. That will effectively cover a vertical distance (or height, z) of 98 meters +/- 145/2 meters, or [25.5 , 170.5] meters (these numbers are calculated and printed in the TurbSim summary file and--I think--on the screen during the OpenFAST simulation). Depending on what size of rotor you are simulating, or if your floating turbine sinks, that grid may not be large enough to avoid this error.

[iosaaaa]

Hi, so I'm still having a similar issue. My TurbSim is running, but when I run openfast, I am getting various errors like this:

FAST_Solution:FAST_AdvanceStates:SolveOption2c_Inp2AD_SrvD:InflowWind_CalcOutput:CalculateOutput:I
fW_FlowField_GetVelAcc:Grid3DField_GetCell: G3D wind array boundaries violated. Grid too small in
Z direction (height (Z=0.98282 m) is below the grid and no tower points are defined).

OpenFAST encountered an error at simulation time 0.7125 of 360 seconds.
Simulation error level: FATAL ERROR

My thoughts are that maybe my tower nodes in aerodyn are not matching up with my TurbSim gridheight. I have attached some files below in case something is standing out to you. Thank you, again!

This is my TurbSim.inp:

TurbSim Input File. Valid for TurbSim v1.50, 25-Sep-2009

---------Runtime Options-----------------------------------
2318573 RandSeed1 - First random seed (-2147483648 to 2147483647)
RANLUX RandSeed2 - Second random seed (-2147483648 to 2147483647) for intrinsic pRNG, or an alternative pRNG: "RanLux" or "RNSNLW"
False WrBHHTP - Output hub-height turbulence parameters in binary form? (Generates RootName.bin)
False WrFHHTP - Output hub-height turbulence parameters in formatted form? (Generates RootName.dat)
False WrADHH - Output hub-height time-series data in AeroDyn form? (Generates RootName.hh)
True WrADFF - Output full-field time-series data in TurbSim/AeroDyn form? (Generates Rootname.bts)
True WrBLFF - Output full-field time-series data in BLADED/AeroDyn form? (Generates RootName.wnd)
True WrADTWR - Output tower time-series data? (Generates RootName.twr)
False WrFMTFF - Output full-field time-series data in formatted (readable) form? (Generates RootName.u, RootName.v, RootName.w)
False WrACT - Output coherent turbulence time steps in AeroDyn form? (Generates RootName.cts)
True Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)
0 ScaleIEC - Scale IEC turbulence models to exact target standard deviation? [0=no additional scaling; 1=use hub scale uniformly; 2=use individual scales]

--------Turbine/Model Specifications-----------------------
13 NumGrid_Z - Vertical grid-point matrix dimension
13 NumGrid_Y - Horizontal grid-point matrix dimension
0.05 TimeStep - Time step [seconds]
450 AnalysisTime - Length of analysis time series [seconds] (program will add time if necessary: AnalysisTime = MAX(AnalysisTime, UsableTime+GridWidth/MeanHHWS) )
400 UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds)
90.00 HubHt - Hub height [m] (should be > 0.5GridHeight)
166.5 GridHeight - Grid height [m]
155.0 GridWidth - Grid width [m] (should be >= 2(RotorRadius+ShaftLength))
0 VFlowAng - Vertical mean flow (uptilt) angle [degrees]
0 HFlowAng - Horizontal mean flow (skew) angle [degrees]

--------Meteorological Boundary Conditions-------------------
"SMOOTH" TurbModel - Turbulence model ("IECKAI"=Kaimal, "IECVKM"=von Karman, "GP_LLJ", "NWTCUP", "SMOOTH", "WF_UPW", "WF_07D", "WF_14D", or "NONE")
"1-ED3" IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. "1-Ed2") )
"A" IECturbc - IEC turbulence characteristic ("A", "B", "C" or the turbulence intensity in percent) ("KHTEST" option with NWTCUP model, not used for other models)
"NTM" IEC_WindType - IEC turbulence type ("NTM"=normal, "xETM"=extreme turbulence, "xEWM1"=extreme 1-year wind, "xEWM50"=extreme 50-year wind, where x=wind turbine class 1, 2, or 3)
default ETMc - IEC Extreme Turbulence Model "c" parameter [m/s]
default WindProfileType - Wind profile type ("JET","LOG"=logarithmic,"PL"=power law,"IEC"=PL on rotor disk,LOG elsewhere, or "default")
90 RefHt - Height of the reference wind speed [m]
18.2 URef - Mean (total) wind speed at the reference height [m/s] (or "default" for JET wind profile)
default ZJetMax - Jet height [m] (used only for JET wind profile, valid 70-490 m)
default PLExp - Power law exponent [-] (or "default")
default Z0 - Surface roughness length [m] (or "default")

--------Non-IEC Meteorological Boundary Conditions------------
default Latitude - Site latitude [degrees] (or "default")
0.05 RICH_NO - Gradient Richardson number
default UStar - Friction or shear velocity [m/s] (or "default")
default ZI - Mixing layer depth [m] (or "default")
default PC_UW - Hub mean u'w' Reynolds stress (or "default")
default PC_UV - Hub mean u'v' Reynolds stress (or "default")
default PC_VW - Hub mean v'w' Reynolds stress (or "default")
default IncDec1 - u-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default IncDec2 - v-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default IncDec3 - w-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default CohExp - Coherence exponent (or "default")

--------Coherent Turbulence Scaling Parameters-------------------
"M:\coh_events\eventdata" CTEventPath - Name of the path where event data files are located
"Random" CTEventFile - Type of event files ("LES", "DNS", or "RANDOM")
true Randomize - Randomize the disturbance scale and locations? (true/false)
1.0 DistScl - Disturbance scale (ratio of wave height to rotor disk). (Ignored when Randomize = true.)
0.5 CTLy - Fractional location of tower centerline from right (looking downwind) to left side of the dataset. (Ignored when Randomize = true.)
0.5 CTLz - Fractional location of hub height from the bottom of the dataset. (Ignored when Randomize = true.)
30.0 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]

==================================================
NOTE: Do not add or remove any lines in this file!

This is my AeroDyn file:

------- AERODYN v15 for OpenFAST INPUT FILE -----------------------------------------------
NREL 5.0 MW offshore baseline aerodynamic input properties.
====== General Options ============================================================================
False Echo - Echo the input to ".AD.ech"? (flag)
"default" DTAero - Time interval for aerodynamic calculations {or "default"} (s)
1 WakeMod - Type of wake/induction model (switch) {0=none, 1=BEMT, 2=DBEMT, 3=OLAF} [WakeMod cannot be 2 or 3 when linearizing]
1 AFAeroMod - Type of blade airfoil aerodynamics model (switch) {1=steady model, 2=Beddoes-Leishman unsteady model} [AFAeroMod must be 1 when linearizing]
1 TwrPotent - Type tower influence on wind based on potential flow around the tower (switch) {0=none, 1=baseline potential flow, 2=potential flow with Bak correction}
0 TwrShadow - Calculate tower influence on wind based on downstream tower shadow (switch) {0=none, 1=Powles model, 2=Eames model}
False TwrAero - Calculate tower aerodynamic loads? (flag)
False FrozenWake - Assume frozen wake during linearization? (flag) [used only when WakeMod=1 and when linearizing]
False CavitCheck - Perform cavitation check? (flag) [AFAeroMod must be 1 when CavitCheck=true]
False Buoyancy - Include buoyancy effects? (flag)
False CompAA - Flag to compute AeroAcoustics calculation [used only when WakeMod = 1 or 2]
"unused" AA_InputFile - AeroAcoustics input file [used only when CompAA=true]
====== Environmental Conditions ===================================================================
"default" AirDens - Air density (kg/m^3)
"default" KinVisc - Kinematic viscosity of working fluid (m^2/s)
"default" SpdSound - Speed of sound in working fluid (m/s)
"default" Patm - Atmospheric pressure (Pa) [used only when CavitCheck=True]
"default" Pvap - Vapour pressure of working fluid (Pa) [used only when CavitCheck=True]
====== Blade-Element/Momentum Theory Options ====================================================== [unused when WakeMod=0 or 3]
1 SkewMod - Type of skewed-wake correction model (switch) {1=uncoupled, 2=Pitt/Peters, 3=coupled} [unused when WakeMod=0 or 3]
"default" SkewModFactor - Constant used in Pitt/Peters skewed wake model {or "default" is 15/32*pi} (-) [used only when SkewMod=2; unused when WakeMod=0 or 3]
True TipLoss - Use the Prandtl tip-loss model? (flag) [unused when WakeMod=0 or 3]
True HubLoss - Use the Prandtl hub-loss model? (flag) [unused when WakeMod=0 or 3]
True TanInd - Include tangential induction in BEMT calculations? (flag) [unused when WakeMod=0 or 3]
False AIDrag - Include the drag term in the axial-induction calculation? (flag) [unused when WakeMod=0 or 3]
False TIDrag - Include the drag term in the tangential-induction calculation? (flag) [unused when WakeMod=0,3 or TanInd=FALSE]
"Default" IndToler - Convergence tolerance for BEMT nonlinear solve residual equation {or "default"} (-) [unused when WakeMod=0 or 3]
100 MaxIter - Maximum number of iteration steps (-) [unused when WakeMod=0]
====== Dynamic Blade-Element/Momentum Theory Options ============================================== [used only when WakeMod=2]
2 DBEMT_Mod - Type of dynamic BEMT (DBEMT) model {1=constant tau1, 2=time-dependent tau1, 3=constant tau1 with continuous formulation} (-) [used only when WakeMod=2]
4 tau1_const - Time constant for DBEMT (s) [used only when WakeMod=2 and DBEMT_Mod=1 or 3]
====== OLAF -- cOnvecting LAgrangian Filaments (Free Vortex Wake) Theory Options ================== [used only when WakeMod=3]
"unused" OLAFInputFileName - Input file for OLAF [used only when WakeMod=3]
====== Beddoes-Leishman Unsteady Airfoil Aerodynamics Options ===================================== [used only when AFAeroMod=2]
3 UAMod - Unsteady Aero Model Switch (switch) {2=B-L Gonzalez, 3=B-L Minnema/Pierce, 4=B-L HGM 4-states, 5=B-L 5 states, 6=Oye, 7=Boeing-Vertol} [used only when AFAeroMod=2]
True FLookup - Flag to indicate whether a lookup for f' will be calculated (TRUE) or whether best-fit exponential equations will be used (FALSE); if FALSE S1-S4 must be provided in airfoil input files (flag) [used only when AFAeroMod=2]
====== Airfoil Information =========================================================================
1 AFTabMod - Interpolation method for multiple airfoil tables {1=1D interpolation on AoA (first table only); 2=2D interpolation on AoA and Re; 3=2D interpolation on AoA and UserProp} (-)
1 InCol_Alfa - The column in the airfoil tables that contains the angle of attack (-)
2 InCol_Cl - The column in the airfoil tables that contains the lift coefficient (-)
3 InCol_Cd - The column in the airfoil tables that contains the drag coefficient (-)
4 InCol_Cm - The column in the airfoil tables that contains the pitching-moment coefficient; use zero if there is no Cm column (-)
0 InCol_Cpmin - The column in the airfoil tables that contains the Cpmin coefficient; use zero if there is no Cpmin column (-)
8 NumAFfiles - Number of airfoil files used (-)
"../5MW_Baseline/Airfoils/Cylinder1.dat" AFNames - Airfoil file names (NumAFfiles lines) (quoted strings)
"../5MW_Baseline/Airfoils/Cylinder2.dat"
"../5MW_Baseline/Airfoils/DU40_A17.dat"
"../5MW_Baseline/Airfoils/DU35_A17.dat"
"../5MW_Baseline/Airfoils/DU30_A17.dat"
"../5MW_Baseline/Airfoils/DU25_A17.dat"
"../5MW_Baseline/Airfoils/DU21_A17.dat"
"../5MW_Baseline/Airfoils/NACA64_A17.dat"
====== Rotor/Blade Properties =====================================================================
True UseBlCm - Include aerodynamic pitching moment in calculations? (flag)
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat" ADBlFile(1) - Name of file containing distributed aerodynamic properties for Blade #1 (-)
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat" ADBlFile(2) - Name of file containing distributed aerodynamic properties for Blade #2 (-) [unused if NumBl < 2]
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat" ADBlFile(3) - Name of file containing distributed aerodynamic properties for Blade #3 (-) [unused if NumBl < 3]
====== Hub Properties ============================================================================== [used only when Buoyancy=True]
0.0 VolHub - Hub volume (m^3)
0.0 HubCenBx - Hub center of buoyancy x direction offset (m)
====== Nacelle Properties ========================================================================== [used only when Buoyancy=True]
0.0 VolNac - Nacelle volume (m^3)
0,0,0 NacCenB - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)
====== Tail fin Aerodynamics ========================================================================
False TFinAero - Calculate tail fin aerodynamics model (flag)
"unused" TFinFile - Input file for tail fin aerodynamics [used only when TFinAero=True]
====== Tower Influence and Aerodynamics ============================================================ [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
11 NumTwrNds - Number of tower nodes used in the analysis (-) [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
TwrElev TwrDiam TwrCd TwrTI TwrCb !TwrTI used only with TwrShadow=2, TwrCb used only with Buoyancy=True
(m) (m) (-) (-) (-)
1.0000000E+01 6.5000000E+00 1.0000000E+00 1.0000000E-01 0.0
1.7760000E+01 6.2400000E+00 1.0000000E+00 1.0000000E-01 0.0
2.5520000E+01 5.9700000E+00 1.0000000E+00 1.0000000E-01 0.0
3.3280000E+01 5.7100000E+00 1.0000000E+00 1.0000000E-01 0.0
4.1040000E+01 5.4500000E+00 1.0000000E+00 1.0000000E-01 0.0
4.8800000E+01 5.1800000E+00 1.0000000E+00 1.0000000E-01 0.0
5.6560000E+01 4.9200000E+00 1.0000000E+00 1.0000000E-01 0.0
6.4320000E+01 4.6600000E+00 1.0000000E+00 1.0000000E-01 0.0
7.2080000E+01 4.4000000E+00 1.0000000E+00 1.0000000E-01 0.0
7.9840000E+01 4.1300000E+00 1.0000000E+00 1.0000000E-01 0.0
8.7600000E+01 3.8700000E+00 1.0000000E+00 1.0000000E-01 0.0
====== Outputs ====================================================================================
True SumPrint - Generate a summary file listing input options and interpolated properties to ".AD.sum"? (flag)
3 NBlOuts - Number of blade node outputs [0 - 9] (-)
1, 9, 19 BlOutNd - Blade nodes whose values will be output (-)
0 NTwOuts - Number of tower node outputs [0 - 9] (-)
1, 2, 6 TwOutNd - Tower nodes whose values will be output (-)
OutList - The next line(s) contains a list of output parameters. See OutListParameters.xlsx for a listing of available output channels, (-)
"RtArea"
"B1N3Clrnc, B2N3Clrnc, B3N3Clrnc"
END of input file (the word "END" must appear in the first 3 columns of this last OutList line)

This is my Turbine Configuration in ElastoDyn:

---------------------- TURBINE CONFIGURATION -----------------------------------
3 NumBl - Number of blades (-)
63 TipRad - The distance from the rotor apex to the blade tip (meters)
1.5 HubRad - The distance from the rotor apex to the blade root (meters)
-2.5 PreCone(1) - Blade 1 cone angle (degrees)
-2.5 PreCone(2) - Blade 2 cone angle (degrees)
-2.5 PreCone(3) - Blade 3 cone angle (degrees) [unused for 2 blades]
0 HubCM - Distance from rotor apex to hub mass [positive downwind] (meters)
0 UndSling - Undersling length [distance from teeter pin to the rotor apex] (meters) [unused for 3 blades]
0 Delta3 - Delta-3 angle for teetering rotors (degrees) [unused for 3 blades]
0 AzimB1Up - Azimuth value to use for I/O when blade 1 points up (degrees)
-5.0191 OverHang - Distance from yaw axis to rotor apex [3 blades] or teeter pin [2 blades] (meters)
1.912 ShftGagL - Distance from rotor apex [3 blades] or teeter pin [2 blades] to shaft strain gages [positive for upwind rotors] (meters)
-5 ShftTilt - Rotor shaft tilt angle (degrees)
1.9 NacCMxn - Downwind distance from the tower-top to the nacelle CM (meters)
0 NacCMyn - Lateral distance from the tower-top to the nacelle CM (meters)
1.75 NacCMzn - Vertical distance from the tower-top to the nacelle CM (meters)
-3.09528 NcIMUxn - Downwind distance from the tower-top to the nacelle IMU (meters)
0 NcIMUyn - Lateral distance from the tower-top to the nacelle IMU (meters)
2.23336 NcIMUzn - Vertical distance from the tower-top to the nacelle IMU (meters)
1.96256 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (meters)
87.6000 TowerHt - Height of tower relative to ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] (meters)
10 TowerBsHt - Height of tower base relative to ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] (meters)
0 PtfmCMxt - Downwind distance from the ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] to the platform CM (meters)
0 PtfmCMyt - Lateral distance from the ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] to the platform CM (meters)
-89.9155 PtfmCMzt - Vertical distance from the ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] to the platform CM (meters)
-0 PtfmRefzt - Vertical distance from the ground level [onshore], MSL [offshore wind or floating MHK], or seabed [fixed MHK] to the platform reference point (meters)

[jjonkman]

Der @iosaaaa,

The error indicates that an aerodynamic analysis node is located at Z=0.98282 m. The lowest node in AeroDyn model appears to be lowest node of the tower, at 10 m. So, the error message implies that the tower is sunk at least 9 m. I would guess that your OpenFAST model is not set up properly, e.g., being numerically or hydrostatically unstable.

Are you using an OpenFAST model provided by NREL or a model you made yourself? If you are using an OpenFAST model provided by NREL, what did you change in the input files?

I would first suggest simplifying your model setup to figure out if your model is numerically or hydrostatically unstable, e.g., by disabling InflowWind, AeroDyn, and ServoDyn altogether. Does your OpenFAST model run as expected with this set up?

Best regards,