FAST.Farm

[Tommi1198]

Hello everyone, I'm trying to run a simulation in FAST.Farm using the NREL5MW wind turbine, but the following error occured:

Farm_Initialize:InflowWind_CalcOutput:CalcOutput:IfW_FFWind_CalcOutput [position=(4980, 4980,
345) in wind-file coordinates]: Error: FF wind array was exhausted at 2 seconds (trying to
access data at -406.96 seconds).

Aborting FAST.Farm.

How can I fix it? Thanks a lot!

[jjonkman]

Dear @Tommi1198,

Have you generated your turbulent wind data file using TurbSim following the modeling guidance documentation: https://openfast.readthedocs.io/en/main/source/user/fast.farm/ModelGuidance.html#inflow-wind-generation? Is the turbulent wind data periodic as recommended? I would not expect that you'd receive an error regarding

FF wind array was exhausted

if the wind data is periodic.

Best regards,

[Tommi1198]

Dear @jjonkman , this is my input file for the wind:

------- 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)
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] =========================
15 HWindSpeed - Horizontal wind speed (m/s)
90 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] ==============
"C:\Users\167544\Desktop\NREL5MW\r-test-main\glue-codes\openfast\5MW_Baseline\Wind\90m_12mps_twr.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)
====================== 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)

[jjonkman]

Dear @Tommi1198,

I don't see any issue with this InflowWind input file. The issue is likely with the TurbSim wind data file you are using, 90m_12mps_twr.bts.

How did you generate this file from TurbSim and is it periodic, i.e., is TurbSim input UsableTime set to "ALL"?

Best regards,

[Tommi1198]

Dear @jjonkman, I took this file from the library in GitHub; in addition, I donìt know how to open this file so that I can check if TurbSim input UsableTime set to "ALL". What can I do? Thank you

[jjonkman]

Dear @Tommi1198,

Presumably you obtained the file 90m_12mps_twr.bts from here: https://github.com/OpenFAST/r-test/tree/main/glue-codes/openfast/5MW_Baseline/Wind; is that correct? The TurbSim input file used to generate this wind data file is available in the same directory, 90m_12mps_twr.inp. In this file, UsableTime is set to 60 s, not "ALL". And there are other input parameters in this TurbSim input file that also do not follow the modeling guidance for TurbSim specified in the FAST.Farm documentation.

The TurbSim input file, 90m_08_mps.inp, found in the following example more closely follows the modeling guidance for TurbSim specified in the FAST.Farm documentation: https://github.com/OpenFAST/r-test/tree/main/glue-codes/fast-farm/TSinflow. I would start with this example.

Best regards,

[Tommi1198]

Dear @jjonkman, I changed the wind file using 90m_08_mps.bts as bts file for TurbSim, but another error came out:

Farm_Initialize:InflowWind_CalcOutput:CalcOutput:IfW_FFWind_CalcOutput [position=(4980, 4980,
345) in wind-file coordinates]: FF wind array boundaries violated: Grid too small in Y
direction. Y=4980; Y boundaries = [-500, 500]

Aborting FAST.Farm.

How can I change the Y boundaries?

This is my input file for the wind:

------- 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)
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] =========================
15 HWindSpeed - Horizontal wind speed (m/s)
90 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] ==============
"90m_08mps.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)
====================== 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)

[andrew-platt]

@Tommi1198

Your turbine is too far out of the bounds of the wind field. About 5 km away from the center based on [position=(4980, 4980, 345). Is that the correct position for the turbine?

[Tommi1198]

Dear @andrew-platt, my turbine is in this position:
WT_X WT_Y WT_Z
(m) (m) (m)
100.0 180.0 0.0

[andrew-platt]

This is a bit puzzling. What is asking for wind 5 km away at position=(4980, 4980, 345)?

[Tommi1198]

I don't really know...

[jjonkman]

Dear @Tommi1198,

My guess is your low- or high-resolution domains defined in your FAST.Farm input file have points that are outside the domain of your TurbSim wind data file.

Best regards,

[Tommi1198]

Dear @jjonkman, how can I see if I have some points outside the TurbSim domain? Because I tried to extend the resolution of the turbine but nothing changed

[jjonkman]

Dear @Tommi1198,

You specify the X-Y-Z extent of the low- and high-resolution domains used by FAST.Farm in the FAST.Farm input file. And you specify the Y-Z extent of the TurbSim domain(s) used by the InflowWind module of FAST.Farm in the TurbSim input file (due to its periodicity, the X-extent of the TurbSim domain is infinite when UsableTime = "ALL"). The low- and high-resolution domains of FAST.Farm must lie within the TurbSim domain (and preferably align with the TurbSim domain to avoid extra interpolation) as discussed in the Modeling Guidance section of the online FAST.Farm documentation: https://openfast.readthedocs.io/en/main/source/user/fast.farm/ModelGuidance.html.

Best regards,

[Tommi1198]

Dear @jjonkman, I have no idea how to open the .bts file to change the domain of the TurbSim input file...I tried to open it with a program found on the internet, but it didn't work