durabol
Well-Known Member
After running some tests (to examine drag of thick laminar sections) with Xfoil these are the lowest drag number I could get for various thickness. These are all just from modifications of existing airfoils by changing the LE radius/camber/thickness/blending.
-25% thickness with 39 drag counts
-22.5% 35
-20% 35
-17.5% 33
-15% 34
-12% 31
-at CL=.15 lowest drag count of 33 with a 17.5% thick airfoil
-at CL=.25 31 12%
-at CL=.40 33 17.5%
I'm wondering how thick laminar airfoils that have low drag with X-foil compare to wind tunnel tests? I have read that computer derived airfoils like Harry Riblett's coincide well with reality. Modern powerful computers and better programs cause me to think a program like X-foil is pretty accurate.
Brock
-25% thickness with 39 drag counts
-22.5% 35
-20% 35
-17.5% 33
-15% 34
-12% 31
-at CL=.15 lowest drag count of 33 with a 17.5% thick airfoil
-at CL=.25 31 12%
-at CL=.40 33 17.5%
I'm wondering how thick laminar airfoils that have low drag with X-foil compare to wind tunnel tests? I have read that computer derived airfoils like Harry Riblett's coincide well with reality. Modern powerful computers and better programs cause me to think a program like X-foil is pretty accurate.
Brock
