Hi Phil,
I'm not trying to be picky, even though it could come across this way, but I do see some conflicting length/width ratios for the minimum airfoil shape posted at EcoModder.
The link below has some information that I will present below, and discuss.
http://ecomodder.com/forum/showthrea...rt-c-9287.html
The image below has sections of several minimum drag sources that show length/width ratios.
Starting from the top of the graphic, the minimum L/W ratio seems to be 2.5:1. I did not scale the graphic closely.
The second graphic shows a ratio of 1.0/.255 = 3.92 L/W
The third graphic clearly shows 2.5 L/W ratio
The C-version Streamlining Template shows a ratio of 4.72/2 = 2.36
I've looked on-line and did not find any other L/W information for subsonic winglets, and minimum drag, so this type of information may be limited to Hucho and other rare sources.
I do recall that you have mentioned that the minimum drag occurs at a L/W ratio of 2.5 many time before, yet some of the other sources do not match this, including the Streamlining Template.
Thanks, Jim.