Process chain to create Aerodyn5_Polar.dat

Wind & Water Airfoils
1

Dear NREL Community

I would like to investigate dynamic stall on a new wind turbine as part of a scientific project at the University of Hannover.

In doing so, I would like to insert the polar information (aoa, cl,cd,cm) from the studied airfoil of the rotor blade into my Aerodyn-setup.

With CFD simulations I calculated the polar information for a range from 10 to 40 aoa (beacause the dynamic separation is assumed at about 17°).

Now the question is how to integrate the generated polar information of the CFD into my Aerodyn setup, i.e. into the Aerodyn15_Polar.dat file. Also, I wonder if I need more CFD results to create a more accurate cl-aoa plot.

My methodology so far is as follows:

  1. convert csv-file of raw data into dat-file
  2. take into account 3D stall effects through Airfoilpreppy.
  3. extrapolate by Airfoilpreppy from -180° to 180°.
  4. save the new polar data in a new csv-file
  5. create Aerodyn15_Polar.dat file by Examlpe5_Writepolar.py code from Demo-python-toolbox

In step 5) I determine the unsteady parameters (like alpha0, cn or cn_lin) which are important to apply at the unsteady aerorodynamis models to predict dynamic stall.

My question are: Is the methodology plausible? Am I missing any step? Could I add a step to get better results? Are more CFD needed for an accurate result?

I am very grateful for any help!

Cheers
Jason

2

Dear @Jason.Printezis,

The process you describe sounds reasonable to me and is the process I expect you’d use.

Best regards,

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