Hi @Jason.Jonkman:
For a fixed base offshore wind turbine, are the tower base moments (given in openfast output) acting where the tower meets the transition piece?
Regards,
AOAW
Dear @Andre.White,
For a fixed base offshore wind turbine, are the tower base moments (given in openfast output) acting where the tower meets the transition piece?
Yes, at an elevation defined by ElastoDyn input TowerBsHt.
Best regards,
Thanks @Jason.Jonkman.
Regards,
AOAW
Dear Sir,
Have you run simulations with a monopile or a jacket? If yes, what monopile dimensions have you referred?
Can you provide the recompiled dll?
Thanks
Subham
Dear @Andre.White
Could you please let me know whether your issue related to changes in the API between different versions of OpenFAST has been resolved? If so, would you be able to share the OpenFAST files for the DTU 10MW turbine that can run with the newer version of OpenFAST? That would be a great help.
Thank you.
Hi NREL,
I have used FAST 3.5.3 with ROSCO 2.7.0 to model the IEA-10MW wind turbine.
Above the wind speed of 12 m/s, FAST is overestimating the GenPwr to 10.5 MW
See the image below
When run with FAST 4.0 and ROSCO 2.9.3 - it’s estimating correctly. GenPwr = 10 MW.
I used the DISCON.IN files corresponding to the version of FAST and ROSCO as given this repo
Can you point me about what could be the reason ?
Thank you,
Ashok
Hi Ashok,
Without more information (time series of generator torque and speed, and the associated DISCONs you used for each run), I cannot account for the difference.
We always recommend using the latest version of tools, so it’s good to see the newer versions behaving as expected. If possible, I recommend using them. If not, I would see what has changed between the DISCON.IN files for each version.
Best, Dan
Hi @Daniel.Zalkind ,
Can you please look into the files and see what has caused the change.
The plot is for 25m/s steady wind. Here is the plot comparing generator torque.
Plot comparing GenPwr
DISCON.IN file for ROSCO 2.7.0 used with FAST 3.5.3
DISCON.IN file for ROSCO 2.9.4 used with FAST 4.0.0
are in the following link
Thank you,
Ashok
Hi Ashok,
The differences in this section seem relevant to your rated power offset. Since the new parameters work well, I would use those.
Best, Dan
Hi @Daniel.Zalkind
Thanks for the clarification
Hi,
The model provided in the repo runs well with Elastodyn
But I want to use BeamDyn for more accuracy. But, looks like the BeamDyn blade file has only 19 stations whereas Elastodyn file has 30 stations.
Is there are way to generate BeamDyn file with 30 stations.
Opened an issue in the repo
For now - I tried by adjusting Elastodyn Blade for 19 nodes and removed some Airfoils in Aerodyn so that the number would be 19.
When I try to run with this configuration - I get the following warnings
It’s 25 mps steady wind.
I am running with FAST 4.0
These are only the warnings - But I couldn’t get them. Will the result be affected by this?
Dear @Ashok.Jammi,
The mesh-mapping error you are receiving is not triggered because ElastoDyn, BeamDyn, and AeroDyn have different numbers of nodes.
In ElastoDyn, the number of blade structural analysis nodes is determined by BldNodes, not NBlInpSt. The values entered at the NBlInpSt are interpolated to the structural analysis nodes.
In BeamDyn, station_total, together with refine, determines the quadrature points, which are the blade structural analysis nodes. With station_total = 19 and refine = 2, you’ll have 37 structural analysis nodes. But again, this does not need to match the aerodynamic analysis nodes in AeroDyn.
Regarding your ROSCO warnings, I would guess your ROSCO input file is not compatible with the version of the ROSCO dynamic library you are using. Changes to the ROSCO input file with each release are documented here: 6. API changes between versions — ROSCO 2.9.4 documentation.
Best regards,
Thanks @Jason.Jonkman .
Just changing the NBlNodes and BldOuts out worked.
Thank you,
Ashok
But then why was mesh mapping error occurring when NBlNds was 30, where BeamDyn was creating 37 nodes ? Why is it resolved with setting NBldNds to 19 in AeroDyn blade.
When I change only Elastodyn “BldNodes” to 19 which was earlier set to 50, I get the error
Dear @Ashok.Jammi,
An error regarding BD_2_AD_BladeMotion is an error in the spatial mesh mapping between BeamDyn and AeroDyn for the motions sent from BeamDyn to AeroDyn. My guess is with the precurve of this blade, there is a small incompatibility between the structural and aerodynamic meshes and eliminating or adding some nodes resolves or triggers the issue. From the issue you opened on the IEAWindSystems repository, it sounds like Mayank and Pietro will look into it.
FYI: ElastoDyn’s input BlDNodes is not used when BModes is enabled.
Best regards,