Inner sections of IEA-15-240-RWT no alpha0 and other parameters

I was wondering why the airfoils IEA-15-240-RWT_Aerodyn15_Polar_03 and IEA-15-240-RWT_Aerodyn15_Polar_04 have no specification of the parameters required for the dynamic stall models. These are not sections with a circular cross section but ‘true’ airfoils.
The sections before and after the ones mentioned, do have this information specified.
Thank you in advance and best regards, Duncan

Hello Duncan,
those airfoils are obtained by interpolating between the cylinder and the first real airfoil, namely the SNL-FFA-W3-500 that is located at 15% of span, see here IEA-15-240-RWT/IEA-15-240-RWT.yaml at 3a00f7f38a6373f6b026aef5878b671ca7af3605 · IEAWindTask37/IEA-15-240-RWT · GitHub
The interpolation causes the polars to be very nonlinear, whereas the scripts to determine the unsteady aero coefficients rely on the successful existence (and identification) of the linear regime, see here WISDEM/ at c07ce084b582322fa2e73da70ce2396abecf6e7d · WISDEM/WISDEM · GitHub.
For these reasons, we decided to turn off the unsteady aero coefficients in those stations.
I hope this helps.
Best regards,

Hello Pietro,
Thank you for taking the time to explain, much appreciated!