airfoil_info for wind turbine blade definition about sharpy HOT 3 CLOSED

Hi kkpal3, thank you for the feedback.

It is the maximum thickness of the airfoil with respect to the chord, check the following image:
https://en.wikipedia.org/wiki/File:Wing_profile_nomenclature.svg
Actually, it is nothing but the standard definition given for example in the definition of the NREL 5MW or in: Abbott, I. H. Theory of wing sections : including a summary of airfoil data. Dover, 1959

The use on UVLM is a bit tricky. First, the airfoils (cylinder, DU40 ...) have certain properties (camber, CL, CD ...). Second, wind turbine blades have varying thickness along the span (check the aero_blade sheet in the excel file). There are some blade sections with thickness that do not appear in the previous table. in these cases, the properties (camber, CL, CD ...) are assigned to those sections as a linear interpolation based on the airfoil thickness.

In the master branch, it is only used to define the camber of the blade as UVLM does not account for thickness itself.

I hope this is useful.
Best regards, Arturo.

from sharpy.

Thank you Arturo for the clarification.
I have another confusion on the excel data sheet. How are the different airfoil shapes assigned to different sections of the wind turbine blade?

from sharpy.

Hi,

they are assigned by linear interpolation. Each airfoil in the "airfoil_info" shape must have the associated coordinates in the "airfoil_coord" sheet. It is easy to see thought the headers.

After that, each section in the blade ("aero_balde" sheet) has a thickness. The shape of each section is obtained through interpolation among the available information in "airfoil_info" and the associated shape in "airfoil_coord".

This is the process conceptually. However, the specific details are tricky. If you want me to be more specific about some point, let me know or you can go through them in the code if you feel comfortable.

Best regards, Arturo

from sharpy.