search

IEAWindTask37 / IEA-15-240-RWT

15MW reference wind turbine repository developed in conjunction with IEA Wind
Apache License 2.0
203 stars 125 forks source link

Inferior blade mass in BeamDyn than in ElastoDyn #193

Closed ghuwart closed 2 months ago

ghuwart commented 3 months ago

Hello, I am trying to run my own model of the IEA15MW with a software that is closer to BeamDyn than ElastoDyn. Therefore, I base my inputs on the full mass and stifness matrices. Yet, I get a lower blade mass than expected and I find the same one by hand or with BeamDyn.

I am wondering if the matrices are not up-to-date.

Description

There seems to be a discrepancy between mass matrices used by BeamDyn and mass data that can be found in the tabular data or when ElastoDyn is run.

In the Overview or Nacelle_mass_properties description: 68.415t With ElastoDyn: 68.507t With BeamDyn: 66.933t By hand with the mass matrices: 66.938t

Current behavior

We get a lower mass for the blades using the full mass-matrix description.

Expected behavior

We find the same mass for the blades using the full mass-matrix description (as in BeamDyn) and the description in ElastoDyn.

ptrbortolotti commented 3 months ago

Hello, Thank you for raising this issue. The ElastoDyn blade file was generated using WISDEM, whereas the BeamDyn files were generated using SONATA. I thought this mismatch was documented somewhere, but I could not find it and I've therefore gone ahead and updated the FAQs here. If I were you, I'd go ahead with the K and I matrices from BeamDyn. I hope this helps. Best regards, Pietro

ghuwart commented 3 months ago

Thank you for your answer and the updated FAQ. Do you think applying a ratio mass_ElastoDyn/mass_BeamDyn could be a quickfix to get the same mass and corrected inertias? I know the difference is not much and that leads to only a 2% error on blade modes but it would align both models. Or would you rather stick with the direct outputs from WISDEM and SONATA?