I ran a test in openfast for the 5MW_Land_BD_DLL_WTurb r-test and when initializing it in the terminal I am getting an error about the nodal outputs not being imported correctly making openfast abort and not giving me proper outputs. If you could help me solve this problem it would be greatly appreciated.
Dear @Hayden.Ntungwe,
The warning about “nodal outputs” is just a warning and will not cause the simulation to abort. The error you are receiving is about not being able to find the DISCON.dll. Is the name and path to your DISCON controller correct in ServoDyn input parameter DLL_FileName?
Best regards,
Thankyou, for the response I have now switched to a computer where the DISCON.dll is not a problem anymore. Is there a way for me to correctly format the nodal output sections of aerodyn so the nodal output section isn’t skipped and the BEM isn’t turned off?
Dear @Hayden.Ntungwe,
You can always ignore the “nodal output” warnings. If you don’t want to see these warnings, add the “nodal output” sections to the ElastoDyn, BeamDyn, and AeroDyn input files, when enabled. See the “nodal output” documentation here:
- ElastoDyn: 4.2.7.2. Input Files — OpenFAST v3.5.0 documentation
- BeamDyn: 4.2.4.3. Input Files — OpenFAST v3.5.0 documentation
- AeroDyn: 4.2.1.2. Input Files — OpenFAST v3.5.0 documentation
In your simulation, BEM appears to be turned off due to a low tip-speed ratio. I see a large skew angle warning before that. I’m not sure why you are getting such a large skew angle, but that sounds unexpected to me and is likely the problem.
Best regards,
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I made some edits within the .fst file following the guidelines for aerodyn nodes that you sent. But, now I’m getting this message about my airfoil file not being real numbers I even changed that first 180.00 degrees to a positive number and go the same outcome. These are the default airfoil files open fast loaded with so I am unsure of the problem.
I got rid of the parsing error. Now is there somewhere I can edit my tip-speed ratio or skew angle to be able to turn on the BEM?
Now its just the tip-screw angle giving me trouble
Dear @Hayden.Ntungwe,
What did you change in the OpenFAST r-test you are using that resulted in this error? Have you changed the wind direction nacelle-yaw angle to force a large inflow-skew angle?
Best regards,
I got rid of the error for the skew angle by going into the aerodyn file and changing my skew mod to 1 instead of 2(as it was before).
Dear @Hayden.Ntungwe,
Changing SkewMod from 2 to 1 will get rid of the skew angle warning, but it won’t eliminate the high skew angle. it looks like you are setting WindType = 2, but then have set Filename_uni = “unused”, which is odd. Moreover, when OpenFAST is run, I don’t see that it is even calling InflowWind, so, I suspect you’ve set CompInflow = 0 (still air), in which case I would not recommending enabling BEM in AeroDyn.
Best regards,
I believe the BEMT and aerodyn are now running fine other then the inflow upflow being 0 but that is fine for now. My goal is to get power(CP), thrust(CT), angle of attack, and angle of induction factor from these calculations. Are there node outputs that allow me to receive those, because I didn’t see them when I read through the choices for outputs in the documentation.
Dear @Hayden.Ntungwe,
Yes, AeroDyn can output RtAeroCp and RtAeroCt at the rotor level in the OutList and AeroDyn can output many things like angle of attack and induction at each analysis node. See AeroDyn’s documentation of the OutList here: 4.2.1.10. Appendix — OpenFAST v3.5.0 documentation and the nodal output documentation here: 4.2.1.2. Input Files — OpenFAST v3.5.0 documentation.
Best regards,
So I applied RtAeroCp and RtAeroCt inside of aerodyn but when I run openfast and look at my output file it looks as if the numbers don’t change.
Dear @Hayden.Ntungwe,
I’m not sure what the difference is between the two output files you shared. And I’m not familiar with your simulation set-up enough to comment whether I would expect the “numbers [to] change”.
Best regards
I would assume that if I just added power and thrust as my output parameters the simulation would know to change the output chart according but, in the case I am showing you if you look at the first few columns and rows you’ll notice that the only thing that is changing is the title of the column depending on how I order the parameters. Also do you have documentation on output charts like the ones I sent earlier?
Dear @Hayden.Ntungwe,
I’m still not understanding what problem you have; it is not easy to interpret when you only upload an image. Are you saying that you have more column headers than columns of data?
Best regards,
I just wanted to say thankyou for helping me with the problems I figured out the last issue that I sent. My new issue has to do with the 5MW_OC4Jckt_DLL_WTurb_WavesIrr_MGrowth rtest and how I am getting erros in the terminal when I compile. I tried fixing the nodal outputs the same way as I did before by adding a nodal output scetion in the .fst file but I’m still getting the multiple node errors. Also, I’m still getting a high angle of attack on top of other new errors. If you can give me guidance on this your help would be greatly appreciated.
Dear @Hayden.Ntungwe,
I’m not sure what you changed in this r-test example, but I do see from your OpenFAST primary (.fst) file that you disabled ServoDyn, HydroDyn, and SubDyn. Why did you do this? Unless you’ve also disabled the generator and platform degrees of freedom in ElastoDyn, this model will not function as expected because the generator speed will not be controlled and there will be no reaction for the platform.
Best regards,
I thought there was no need to have a ServoDyn, HydroDyn, or SubDyn enabled since I really only want the aerodynamic outputs from aerodyn. I went into the ElastoDyn and notcied that generator and platform degrees were enabled but I still got the above errors. I turned on the servo and Hydrodyn and got these follwoing erros in my terminal.
