Interpreting certain German airfoils

[s.flying]

Does anyone know how to interpret certain German airfoils like the ones from Heinkel, Blohm Voss and Arado?

Here's an example

Heinkel He 177
Wing Root: He 1.5 36.8 17.3-0.715-36.6
Wing Tip: He 1.5 36.8 10-0.715-36.6

Arado Ar 234
Wing Root: Ar 1.267 20 13-1.1-35
Wing Tip: Ar 1.227 20 10-1.1-30

 

[Snautzer01]

Try:

https://www.google.nl/search?q=airf...rd=cr&ei=FSuMVPbzNYXBPPvIgdgL#q=naca+airfoils

 

[s.flying]

Okay, i think i figured this out.

The Arado Ar 234 airfoil (Ar 1.267 20 13-1.1-35/Ar 1.227 20 10-1.1-30) is basically a NACA 12013 (Root) and NACA 12010 (Tip) with modifications to the first digits (theoretical optimum lift coefficient). The last four digits after the dashes are standard German modifications applied to a several dozen of NACA airfoils.

Would like to hear your thoughts on this.

 

[Simon Thomas]

He 1.5 36.8 17.3-0.715-36.6

1.5 - Depth of camber, percent
36.8 - Distance of maximum camber from leading edge, percent
17.3 - Thickness ratio, percent
0.715 - Nose radius, percent
36.6 - Backward position of maximum thickness from nose, percent

From NACA TM 1240 https://digital.library.unt.edu/ark:/67531/metadc65415/m2/1/high_res_d/19930090916.pdf

My WAG is that by the time this nomenclature was in use, the Germans had moved away from modifying the NACA 4 and 5 digit series and were developing their own aerofoils.