Hi again Jason,
I wrote some time ago because I was trying to adapt an V27 OpenFAST model to the new turbine Orcaflex feature and I had some doubts about the definition of certain parameters you very kindly clarified.
In that time you told me the neutral axis in ElastoDyn is assumed to lie on the pitch axis. As I had the corresponding “…_ElastoDyn_Blade.dat” file containing the pitch axis list I took that data. However, even then the distribution of the pitch axis there specified seemed a bit weird to me, since it placed the pitch axis for the root cylinder and thicker, near to root profiles, already at ~26% of the chord from the leading edge instead of 50% for the cylinder and near to 50% values for the inmmediate following sections, which is what would have seem reasonable to me.
After that, checking on the Orcaflex adaptation of the 5 MW NREl tubine Orcina did, I realized they had taken Pitch/netral axis values from the list you provided in a post of the following thread: NREL 5MW Rotor Geometry (Fri Jan 28), but these values are different from those other specified in the NRELOffshrBsline5MW_Blade.dat file , downloaded with the F8/OpenFAST archive. The values on the list you provide in the forum post make sense to me, while similarly to the case of the V27 FAST model I am trying to adapt, the list on the “…blade.dat” file don’t.
I was wondering if there is some transformation here needed that I am missing…Why are the values for the pitch axis distribution different on the list you provided on the post compared to those in the 5MW baseline files?
I am attaching the files I make reference to.
Thank you in advance for your time.
Best regards,
Rocío Torres
5MW_Blade_posted.txt (1.52 KB)
SNLV27_ElastoDyn_Blade.txt (5.09 KB)
NRELOffshrBsline5MW_Blade.txt (6.57 KB)