an overview of what's coming...
this post focuses on "Hoerner Wingtips"
One of the absolute joys of my pseudo-job is that I get to investigate, implement and test aerodynamic improvements to my Belite ultalight airplanes. As a result, I have come up with a goal of decreasing drag on our aircraft so that our very smallest engine option will allow cruising flight at 62mph. (And the larger engines will require throttle limitations in order to stay within Part 103 -- or registration as experimental aircraft.)
When all is implemented, this will provide important improvements to takeoff and landing performance, along with substantial improvements to climb rate, reduced stall speeds.
Because our aircraft is so similar to a conventional high wing aircraft, I have identified several opportunities for drag reduction which are already available on many 'commercial' certified aircraft. These opportunities include:
a) lift strut drag reduction via fairings -- all airplanes should have this
b) wingtip drag reduction via reduction of wingtip vortices
c) increased Lift / Drag in wing airfoil via subtle improvements
d) reduced drag due to improved cowling design
e) And maybe there will be more.
(none of these future options have been made available, or even priced yet)
I've already implemented and test flown a Belite with lift strut fairings, and I will provide a full report soon. Hint at the outcome: It was awesome.
I'm also working on a changed cowling design -- it will take a few more months and I'll have that one ready for report.
I've been reading through a variety of aerospace engineering reports on wing airfoils. I find that my engineering and math background are an excellent helper for me as I've learned more and more about airfoils.
As for wingtip vortices, lots of people already know that Dr. Hoerner tested many different types of wingtips, in order to select and document those which increased effective span and reduced drag by reducing or eliminating those nasty wingtip vortices. I happen to have gotten my hands on a copy of a couple of his books (they were loaned to me by a friend at my Church) and they have been delicious reading for my ultralight aircraft aerodynamic engineering education.
So, here's some photos of a set of wings in construction progress, showing Hoerner wingtips being fabricated. These will end up on a plane which is being built to exhibit at Sun N Fun in 2012. No opportunity for improvement is being overlooked in this airplane. The wings in question are carbon fiber spars, with aluminum ribs, and the Hoerner wingtips. You may also notice that they are also being prepared for VFR night flight via the addition of wingtip lights. (The airplane is being built with a heavy 4 stroke engine, and will be registered experimental, thus allowing night flight. It will be also be flyable as a legal FAR Part 103 airplane, albeit with a different engine.). (This particular set of wings is being built by builder Mike. Mike is awesome.)
So here are the pictures:
|Belite Ultralight Aircraft wing, under construction with Hoerner wingtip|
|Detail of Hoerner wingtip, showing nav light fairing|
|Front view of Hoerner wingtip, with much smooth work still to do|
|Quartering view of Hoerner wingtip|
|View of Hoerner wingtip, prior to adding foam to front cell|
|Trailing edge quartering view of Hoerner wingtip|
|View of Hoerner wingtip from outside rear|