## Aerodyn v14 about the Nfoil choosing

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Yun.Lu
Posts: 7
Joined: Mon Jan 14, 2019 1:12 am
Organization: self
Location: China

### Aerodyn v14 about the Nfoil choosing

Dear Jonkson,
I have one question about the 'NRELOffshrBsline5MW_AeroDyn.ipt' file content. I know the 'RNodes' shoud be equal
RNodes(2) = RNodes(1) + ( DRNodes(1) + DRNodes(2) )/2
RNodes(i) = RNodes(i-1) + ( DRNodes(i-1) + DRNodes(i) )/2.
And I know the 'FoilNm' about aerodynamic data is according to the thickness chord ratio(for example "AeroData\DU40_A17.dat",its aerodynamic data at the 40% thickness chord ratio station). My question is how to choose the 'Nfoil' parameters at every RNodes?(for example,when RNodes equal to 11.75,does the thickness chord ratio equal to 40%? Or just equal approximatively?). At every RNodes, does Nfoil correspond to the accurate thickness chord ratio airfoil aerodynamic data ? Should we calculate every RNodes station airfoil aerodynamic data ?

Best regards,

Jason.Jonkman
Posts: 4627
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
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### Re: Aerodyn v14 about the Nfoil choosing

Dear Yun.Lu,

I'm not sure I understand your question, but the airfoil at each aerodynamic analysis node should be set based on the appropriate airfoil characteristics at that node. The characteristics at a given node could depend e.g. on its airfoil shape (including thickness), Reynold's number, and rotational augmentation.

I hope that helps.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov