FAST.Farm

[Younes.Oudich]

Dear Jason,

I am very interested in Fast.Farm with the Super Controller for my PhD project. Could you please share with me the FAST.Farm pre-release version along with its documentation?

Thank you in advance.

Best regards,

Younes

[Jason.Jonkman]

Sent.

[Bruno.Lopez]

Dear Bruno,

Yes, I would guess it is the operation in Region 1.5 that is causing a high tip-speed ratio and high thrust.

It would be hard to see the effect from the OpenFAST *.out file. Instead, I would output a VTK slice (e.g., a XY plane through the hub), and you'll clearly see the wake expand just before the near-wake correction error is displayed.

The improved near-wake correction model that we are working on now will resolve this problem. Until then, dropping C_NearWake is the only the solution that does not involve a source-code change.

Best regards,

Dear Jason,

Yes, that's is exactly what I tried to say in my previous post. The wake expansion doubles de rotor diameter when looking at a vtk slice just before the error occurs, which makes no physical sense.

Thanks for your suggestions! I look forward for updates regarding the near wake correction.

Best regards,
Bruno

[Eduardo.Paiva]

Dear Jason,

Could you share with me the FAST.Farm pre-release version along with its documentation, please?

Thanks for your attenttion,

[Jason.Jonkman]

Sent.

[Jiaping.Cui]

Dear Jason,

I can run the 5.0 MW Baseline Wind Turbine with OC3 Monopile RF configuration, OC3 Hywind configuration and OC4-DeepCwind semi configuration in FAST.Farm successfully. But when I used the MIT-NREL TLP Configuration without any changes in FAST.Farm, it will have errors. So have the TLP configuration some special points that need to set in the primary files ? The errors as followings:

FARM_InitialCO:AWAE_CalcOutput:LowResGridCalcOutput:The center of a wake plane for turbine #1 has
passed the lowest-most Z boundary of the low-resolution domain.
T1:FARM_InitialCO:FWrap_t0:FAST_Solution0:CalcOutputs_And_SolveForInputs:SolveOption2:SolveOption2
c_Inp2AD_SrvD:InflowWind_CalcOutput:CalcOutput:IfW_4Dext_CalcOutput [position=(0, 0, 0) in
wind-file coordinates]:Interp4D:Outside the grid bounds.
SolveOption2:SrvD_CalcOutput:Running with torque and pitch control of the NREL offshore 5MW
baseline wind turbine from DISCON.dll as written by J. Jonkman of NREL/NWTC for use in the IEA
Annex XXIII OC3 studies.



Aborting FAST.Farm.

This error occurs in the initialization stage of the simulation, so I decided the cause may be improper domain specification, but why the other kinds of wind turbine have not this problem ?

And I also want to initialize the rotor speed and blade pitch to their expected values for the given mean hub-height wind speed, but I don't know every wind speed correspond to the blade pitch ? Have it a table that we could reference ？

Best regards,

Jiaping.Cui

[Younes.Oudich]

Dear Jason,

Using the example given in Fast.Farm, I always get issues of computation when I change the wind turbines positions (only by 20m in the Y direction), saying that it is out grid bounds (as you can see in the Matlab consol). But from the parameters given: NX_low=500; NY=200; dX_Low=10m; dY_Low=10m; the length of the boundaries are Lx=10.(500-1)=4990m and Ly=10.(200-1)=1990m, and the turbines in the Y axis are in 1020m;980m;1000m; which are inside the grid bounds. Maybe I missed something, but I can't figure out the issue. Can you help me please?

Kindest regards

Younes

[Jason.Jonkman]

Dear Jiaping.Cui,

My guess is you are receiving the error about position = (0,0,0) because the tower aerodynamic analysis nodes in the AeroDyn v15 input file for the MIT/NREL TLP model extend down to ground level. To solve this problem, extend the FAST.Farm domain lower (to ground level), increase the lowest-most tower node in the AeroDyn v15 input file, or disable tower aerodynamics altogether.

Regarding the expected values of the rotor speed and blade-pitch angles for the NREL 5-MW baseline wind turbine as a function of mean hub-height wind speed, please see the following forum topic: viewtopic.php?f=2&t=363&p=13693.

Best regards,

[Jason.Jonkman]

Dear Younes,

The error message you are getting is referring to the high-resolution domains, not the low-resolution domain. When you shifted the Y-locations of the wind turbines in FAST.Farm, did you also shift the location of the high-resolution domains?

Best regards,

[Younes.Oudich]

Dear Jason,

I changed the high-resolution domain position and it works. Thank you so much!
I have another question: How the ambient wind is generated (the .vtk files)? Is it with TurbSim?
I would like to generate my own wind conditions and test my wind farm on it.

Kindest regards

Younes Oudich

[Jason.Jonkman]

Dear Younes,

The ambient wind in VTK format used by FAST.Farm (Mod_AmbWind = 1) is generated by a high-fidelity precursor simulation (CFD), e.g., SOWFA. You can use TurbSim to generate ambient wind using Mod_AmbWind = 2 or 3. See the draft FAST.Farm User's Guide and Theory Manual for more information.

Best regards,

[Ertem.Vehid]

Dear Jason,

Could you please send to me the pre-release of the fast.farm software together with its documentation? I am interested to compare it with some of our internal tools.

Thank you in advance.

Kind regards,

Ertem

[Jason.Jonkman]

Sent.

[Eduardo.Paiva]

Dear Jason,

I am trying to use InflowWind module with FAST.Farm, but I keep getting the following error:

Code: Select all

T1:FARM_InitialCO:FWrap_t0:FAST_Solution0:CalcOutputs_And_SolveForInputs:SolveOption2:SrvD_CalcOut
put:Running with torque and pitch control of the NREL offshore 5MW baseline wind turbine from
DISCON.dll as written by J. Jonkman of NREL/NWTC for use in the IEA Annex XXIII OC3 studies.
T2:FARM_InitialCO:FWrap_t0:FAST_Solution0:CalcOutputs_And_SolveForInputs:SolveOption2:SrvD_CalcOut
put:Running with torque and pitch control of the NREL offshore 5MW baseline wind turbine from
DISCON.dll as written by J. Jonkman of NREL/NWTC for use in the IEA Annex XXIII OC3 studies.
T3:FARM_InitialCO:FWrap_t0:FAST_Solution0:CalcOutputs_And_SolveForInputs:SolveOption2:InflowWind_C
alcOutput:CalcOutput:IfW_4Dext_CalcOutput [position=(-5, 0, 90) in wind-file
coordinates]:Interp4D:Outside the grid bounds.
SolveOption2:SrvD_CalcOutput:Running with torque and pitch control of the NREL offshore 5MW
baseline wind turbine from DISCON.dll as written by J. Jonkman of NREL/NWTC for use in the IEA
Annex XXIII OC3 studies.
FWrap_t0:FWrap_CalcO

 Aborting FAST.Farm.


I changed X0_low and Y0_low to include this position (-5, 0, 90) but it didn't solve the problem.
I am using the example file for FAST.Farm, all I changed was Mod_AmbWind to 2 (to use the inflow module)

Here is the relevant part of the inflow file

Code: Select all

------- InflowWind v3.01.* INPUT FILE -------------------------------------------------------------------------
Sample InflowWind input file.
---------------------------------------------------------------------------------------------------------------
False         Echo           - Echo input data to <RootName>.ech (flag)
1   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)
0.0                PropagationDir - Direction of wind propagation (meteoroligical rotation from aligned with X (positive rotates towards -Y) -- degrees)
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] =========================
16   HWindSpeed     - Horizontal windspeed                            (m/s)
90   RefHt          - Reference height for horizontal wind speed      (m)
0   PLexp          - Power law exponent                              (-)


Can you help me with this?

Thanks in advance

[Jason.Jonkman]

Dear Eduardo,

From the error message, it appears that turbine #3 falls outside of its corresponding high-resolution domain. How is the high-resolution defined relative to the location of turbine #3? Can you attach your FAST.Farm input file?

Best regards,