Open abdullah-74 opened 2 months ago
Dear @abdullah-74,
Can you clarify what you changed when you refer to rotating the wind farm and support structures by 180 deg?
Best regards,
Dear @jjonkman,
I followed guidance from previous questions on how to rotate wind farm from the NREL forum, so what I did was:
• Keep ‘PropagationDir’ equal to 0deg; • Set ‘PtfmRefzRot’ in ‘HydroDyn’ input module to 180 • Rotate the positions of the fairlead/anchors in the ‘MoorDyn’ input module by 180 deg • Rotate the joints in the Morison elements, which can be found in the ‘HydroDyn’ input module under ‘MEMBER JOINTS’ by 180 deg
Many thanks,
Here are my input files, in case you would like to have a look Input files.zip
Dear @abdullah-74,
I haven't reviewed your input files in great detail, but how you describe the wind farm rotation makes sense to me.
I'm not fully sure I know what is going on, but is there a reason why the wind point you are outputting wind at is located 210-m downstream of each turbine?
Does the flow visualization you are generating (e.g., via NOutDisWindXY
= 1 with OutDisWindZ
= 90 m) offer a clue as to what is happening?
Best regards,
Dear @jjonkman,
I have realised the 'InflowWind' module I included in my input zip file is of the 2nd case (when I do not rotate the wind farm). The reason I am outputting wind 210-m downstream of each turbine is that that is the PtfmSurge of T2 and I am interested in the wind speed just before that. The outputting wind in case 1 (where I rotate the wind farm) is:
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)
The flow visualization for case 1 is below taken at 1998 s and 2997 s, respectively:
It is clear from this that incoming freestream wind is disturbed but I am not sure why this would be the case.
Many thanks,
Dear @abdullah-74,
Can you share the input files for the case you are showing the visualization of?
Best regards,
Dear @abdullah-74,
Based on your input files, I'm not sure where the flow disturbance upstream of the first turbine is coming, but I haven't tried to run your simulation myself. Perhaps this is from some start-up transient involving large floater motion? Do the visualizations earlier in the simulation offer a clue?
Best regards,
Dear @jjonkman,
Thank you for you advice, I think I will have a look at this and have a play around trying to diagnose the issue and will let you know of any updates.
Many thanks,
Dear @jjonkman,
I am using Fast.Farm ver 3.5.3 to conduct simulations for 1x3 wind farm with NREL 5MW offshore wind turbine constructed on a semi-submersible platform. I have rotated the wind farm and all offshore support structures by 180 deg, to simulate the case for wind along the negative x-axis (The wind in simulation is coming from the positive x-axis as PropagationDir = 0).
When I set the wind type as steady wind at 12 m/s, I see sudden sharp changes in wind speed at certain points (see below). This also occurs for Turbine 1 which should be receiving free stream wind conditions.
Even if I do not rotate the wind farm and offshore support structures T2 and T3 still experience this sudden change in wind speed.
I am not quite sure why this is the case.
Thank you in advance.