AJLiberatore
Registered User
a couple of photos
A fan of aircraft design on this end for eons including wingtip design. I can't wait to hear performance numbers aka what type of improvement on the top on bottom end. This particular shape I have been doodling for over a year (with other components as well), and trying to figure out how to do in Solidworks, it maybe trickier than it looks, but let that go. This shape dovetails in a way off of the "Elipse Tips" the L-39 racers are using and the later RV-Tips that went from Hoerner to this 1/4 Ellipse style of which there is some data on the web, but it is hard to find.
If you read Harry Riblett's book and look at the Sullivan & Metcoair tips the trailing edge of those tip and Harry's recommendation is trailing edge of the tip be colinear with the wings trailing edge. This tip does that and if I see it correct, it takes the existing 40's trainer bow type tip ( of which we know now may not be the best ) and extends the tip back and make the trailing edge colinear. If this works, how is this not a slam dunk modification/potential STC and or 337 for a host of 40's (and later) fabric favorites?
Reading on aero design especially at the tip and if you look at what Steve Wittman did with his W-10 tip, you get a sense the last 20% or so the vorticies are trying to go span wise, rap up and over and head towards the tip and generally be a pain. Thinking out loud, but by putting area outboard of the aileron to allow this to happen and keep the ailerons happy and delay all the calamity by the trailing edge being all the way aft and perhaps putting the vorticies to work maybe a good thing. The 2 SW-Piper STC's and what the Seabee guys did via their extensions outboard of the ailerons make a heck of a lot of sense if what I am thinking actually is valid.
Tangent subject matter is what Al Bowers and the Prandtl Wing does with that last 20% or so the dramatic twist they use, but that is way off topic, other than the 20%....
My best,
Anthony