Dear Ruiyang.He,
I’m not sure, but I’m not an expert in ParaView. If someone else can’t respond here, this may be a better question to ask to ParaView techcnial support.
Best regards,
Dear Jason,
Thanks for your kind response all the time.
I will post it on Paraview forum.
Best regards,
Ruiyang He
Dear Ruiyang
I might help with ParaView. I see in your picture that there is no plan (XY, XZ or YZ) that is selected. The only thing plotted in your case is the low-resolution border. In order to plot wind speeds of different plans, you should set the number of plans of each plan (for instance NOutDisWindXY=1 for a single XY plan), and their positions (for instance the XY plan is set at z=90m height). Below, an example of the VISUALIZATION part in my FSTF input file to plot 1 XY plan at z=90m and 4 YZ plans at different x positions.
--- VISUALIZATION ---
False WrDisWind Write low- and high-resolution disturbed wind data to <RootName>.Low.Dis.t<n>.vtk etc.? (flag)
1 NOutDisWindXY Number of XY planes for output of disturbed wind data across the low-resolution domain to <RootName>.Low.DisXY<n_out>.t<n>.vtk (-) [0 to 9]
90.0 OutDisWindZ Z coordinates of XY planes for output of disturbed wind data across the low-resolution domain (m) [1 to NOutDisWindXY] [unused for NOutDisWindXY=0]
4 NOutDisWindYZ Number of YZ planes for output of disturbed wind data across the low-resolution domain to <RootName>/Low.DisYZ<n_out>.t<n>.vtk (-) [0 to 9]
126.0, 630.0, 1134.0, 1386.0 OutDisWindX X coordinates of YZ planes for output of disturbed wind data across the low-resolution domain (m) [1 to NOutDisWindYZ] [unused for NOutDisWindYZ=0]
0 NOutDisWindXZ Number of XZ planes for output of disturbed wind data across the low-resolution domain to <RootName>/Low.DisXZ<n_out>.t<n>.vtk (-) [0 to 9]
126.0, 504.0 OutDisWindY Y coordinates of XZ planes for output of disturbed wind data across the low-resolution domain (m) [1 to NOutDisWindXZ] [unused for NOutDisWindXZ=0]
10.0 WrDisDT Time step for disturbed wind visualization output (s) [>0.0] or DEFAULT [DEFAULT=DT] [unused for WrDisWind=False and NOutDisWindXY=NOutDisWindYZ=NOutDisWindXZ=0]
Once the simulation done, in ParaView, you should select all the plans (make sure they have “XY”, “XZ” or “YZ” on them)
I hope this helps.
Kindest regards
Younes
Dear Ruiyang
I think I found what you want. If you want to plot the velocity volume/surface/points using WrDisWind=1, you should change the parameters in Paraview as below: (Velocity; Magnitude; Surface) Or you can play with it to have the desired visualization (Points instead of Surface for example).
I hope this helps
Kindest regards
Younes
Dear Younes,
Thank you very much for your help. I really appreciate that!
Others who have similar problems could also see cfd-online.com/Forums/ope…y-problem.html.
Now I have another question that can vtk files of fast.farm produce a similar figure like what is attached below? Which is actually made by the output of SOWFA.
How to do it in Paraview?
Thanks
Ruiyang He
![Image [2].png](https://europe1.discourse-cdn.com/nrel/original/2X/3/3905507542e6ff64c9c3b5f874389e29f254d0e7.png)
Dear Ruiyang
I am glad I could help a bit.
For the attached image of SOWFA, I don’t know if it is possible to get a similar image thanks to FAST.Farm and ParaView. But what you can have, is by adding the Visualization part from OpenFAST (WrVTK=2 and VTK_type =1 in the .fst wind turbines files), and by playing with the section and the opacities of the plans, you can have an image (or even animations with the rotation of the turbine and the meandering of the wake effect) like the one below.
Maybe this can help get a beautiful animation or image as you wanted.
Kindest regards
Younes
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Dear Younes,
Thanks a lot for your help again!
The figure you provided looks gorgeous. I will try it soon!
Best regards,
Ruiyang He
Dear Jason,
Now I adopt the WindVxiList, WindVyiList, WindVziList in inflowWind referenced in openfast to represent the velocity at rotor plane of individual WT in a wind farm. I am wondering if there is any parameter in either openfast or fast.farm to calculate the turbulent intensity at rotor disk of any given rotor disk?
Because I found TIAmbT α can only represent the ambient TI of the wind at given rotor disk.
Thanks,
Ruiyang He
Dear Jason,
I want to try to output the speed distribution (U, V, W) of radial nodes over time in different downstream NDs, when I add WKDFVXT19D8 (ie, the 19th Node at the downstream 8D) by the output list of FSTF files, Only the value of the wake deficit can be seen, i don't know which method that i can get the outputs of U, V, W distribution of the point in downstream location ?If i need to modify the source code, which file should I modify?
thanks,
Wang Jundong
Dear Ruiyang.He,
OpenFAST does not directly output the TI, but you can output the wind velocity at user-defined points from InflowWind as you describe, and then calculate TI (standard deviation divided by mean wind speed) in a post-processing step.
Dear Wang Jundong,
FAST.Farm doesn’t currently track or output the ambient or disturbed (ambient + wakes) wind velocity at locations along the wake planes. However, you can output the ambient and disturbed wind speeds at points in the low-resolution domain by using the WηVAmbδ and WηVDisδ outputs in the FAST.Farm OutList. Moreover, you can output the disturbed wind velocity at XY, YZ, or XZ cross planes of the low-resolution domain or output the full ambient and disturbed velocity field across the low-resolution and all high-resolution domains via the outputs in the VISUALIZATION section of the FAST.Farm input file.
Best regards,
Dear Jason,
Thanks for your reply and i will try it later.
And i have another idea——can I obtain the wind speed distribution data on the sweep surface of the second wind turbine ? Or the U,V,W wind speed at some point along the radius of the blade …？
By the way , i read the dos named InflowWind_Manual.pdf , set the the parameter ‘NWindVel’ =4 and complete the setup in the fstf and inflowwind.dat files following the guidence, which can be seen as following:
when i check the T1.out or T2.out file , only Wind1VelX/Y/Z can be seen.
so i wanna know :
- How to set the output of the parameter ‘NWindVel’ correctly?
- ‘WindVelX’ means the list of coordinates in the X direction for wind output (m), i saw related output in the T2/T3.out file , so the origin of ‘coordinate’ system is the corresponding turbine right?
Wishing your reply.
Best regards,
Wang jundong
Dear Wang Jundong,
You can output the local wind velocity distributed along the blade (including ambient wind and wakes from upwind turbines, but not include the induction from the current wind turbine) through AeroDyn outputs BαNβVUndx, BαNβVUndy, BαNβVUndz, as documented here: openfast.readthedocs.io/en/main … t-channels.
You mention the InflowWind documentation, but it looks like you are set NWindVel, etc. in the FAST.Farm input file. So, the outputs you are specifying are FAST.Farm outputs (in the global coordinate system of FAST.Farm), not InflowWind outputs. The InflowWind outputs for each wind turbine are specified in the InflowWind input file that is referenced in the OpenFAST primary input file of each wind turbine. The outputs specified in the InflowWind input file are in the local coordination system of each wind turbine.
Best regards,
Dear Jason,
I have two questions for your advice.
First. There was a problem that bothered me for a day. The first picture is based on SOWFA simulation[1], and the second is the simulation result I made with Farm. The same is to move the position of the second turbine. My trend from -140m to 140m is exactly the opposite of the result in the SCI paper (the first picture). The power of 50m in his picture is greater than -50m, and the power of 100m is greater than -100m; but mine is just the opposite. I checked my coordinates and there is no problem, can you help me think about what might be wrong？
[1] Gebraad, P. M. O. , et al. “Wind plant power optimization through yaw control using a parametric model for wake effects—a CFD simulation study.” Wind Energy 19.1(2016):95-114.
by the way i want to know does FAST.Farm consider in-plane-velocity when calculating the wake plane? Which i think is one of the reason for this problem.
Second. Although I have read the introduction to the interaction and coupling of various modules in the farm, I am still a little confused whether the turbine will interact with the Farm after one revolution, or several revolutions (related to the set DT)?
Wishing your reply.
Best regards,
Wang jundong
Dear Wang Jundong,
Assuming zero yaw error, the wake meandering in FAST.Farm should not be biased to one side, assuming your simulation is long enough to ensure statistical significance. So,I’m guessing the asymmetry in the FAST.Farm result is a result of the horizontal wake deflection correction (the four inputs in FAST.Farm beginning with C_HWkDfl_O). You could set these all to zero to eliminate any asymmetry or to swap the asymmetry.
I’m not sure I fully understand your questions about “in-plane velocity” or rotor rotation; can you clarify?
Best regards,
Dear Jason,
Thanks for your advice! I’ll try it as you said.
In-plane velocity: what I mean here is that in the rotor rotating plane of up stream turbine that the rotating blades produce the swirling effects due to the drag of blades propagate into DWM modeling that may be carried out into the wake when it hits the down stream turbine.
Another question: although I have read the introduction to the interaction and coupling of various modules in the farm, I am still a little confused whether the turbine(openfast) will interact with the FAST.Farm driver after one revolution, or several revolutions (related to the set DT)?
Best regards,
Jundong Wang.
Dear Wang Jundong,
The swirl of the wake is not incorporated into the existing asymmetric wake model of FAST.Farm. That said, we are working on the implementation of a new curled wake model (where wake curl is produced under skewed flow) and have included the swirl of the wake in that implementation.
The FAST.Farm modules interact at the low-resolution time step (DT_Low), which should be set to a time step consistent with wake dynamics (typically a second or two). The high-resolution wind domains around each wind turbine should be updated at a faster time step (DT_High) for the purposes of generating higher-frequency inflow data to excite the wind turbine (typically covering the lowest natural frequencies and rotor harmonics of the wind turbine. The OpenFAST model will simulate at the time step specified in the OpenFAST model (DT), which is typically small enough to ensure numerical stability and to capture all relevant natural frequencies and rotor harmonics. More information on time steps is documented in the online FAST.Farm User’s Guide and Theory Manual: openfast.readthedocs.io/en/main … index.html.
Best regards,
1 Like
Dear Jason,
Thanks so much!
Happy New Year!
Best regards,
Wang jundong
Dear Jason,
I am learning about the effect of yaw control on turbines’ power and load, in my simulation, upstream turbine is WT1, followed by WT2 and WT3, I use fast.farm tool to do simulation and made an comparation with sowfa (Refer to the conclusion of fig. 2). Different precision is the biggest difference between them theoretically, but in fact, in the WT1 yaw misalignment angle for clockwise, WT1 load is reduced, but my simulation results is as long as WT1 yaws, WT1 load increases, could you help me analyze the reasons?
Thank you very much!
Best regards,
Liye
Dear Liye,
Can you clarify what paper you are referring to with the SOWFA results? I’m actually quite surprised that SOWFA would predict an out-of-plane (OoP) blade bending moment DEL that is asymmetric with respect to yaw error for the upstream turbine (WT1). According to the following paper by Damiani et al, where FAST v8 is compared to field measurements in yaw, the flapwise blade moment DEL (which should be similar to OoP) is quite symmetric with yaw error: wes.copernicus.org/articles/3/173/2018/. That said, the edgewise blade bending moment DEL (which should be similar to in-plane (IP)) does show an asymmetry with respect to yaw error.
For WT2 and WT3, some asymmetry with error in OoP blade bending moment DEL is expected because the deflection of the wake from WT1 is not symmetric with yaw error.
Best regards,
Dear Jason,
Thank you for your analysis and the recommended reference paper, the paper I referd was “Simulation Comparison of Wake Mitigation Control Strategies for a Two-Turbine Case”.
Best regards,
Liye
Fleming-2015-Simulation-comparison-of-wake-mitig.pdf (2.8 MB)