by Ground Slammer » Thu Aug 31, 2017 9:07 pm
For those who read the Quickerus article, and those that have not, the Quickerus shows that with equal cord, span, taper, and twist it preforms equal to the IcarusV-but this is a moot point for my proposal. The 11 plus degrees of twist can be pulled way down now that the wing has a stabilizer-at this point it will exceed the performance of the parent wing. Also the stabilizer incidence can be reduced due to the contribution of the reflex- but this is a moot point for my proposal.---- So one can beat the performance of the parent wing.
Large aircraft that are so equipped will deflect their ailerons to negative settings after climb out-that is reflex the wing. This results in the aircraft speeding up while reducing fuel consumption. If the aircraft then reduces the stabilizer incidence it trims out with lower parasitic drag too. The negative flaps lowers the Coef.of lift and lowers the profile drag-the wing speeds up and cruses with less drag.
As I stated above this is a moot point for my proposal-this is because the B-6407-E is not a flying wing airfoil to begin with! The B-6704-E is a competition Nordic Glider airfoil. Nordic Gliders are very large R/C sailplanes-some with wing spans over 4 meters-larger than Hall Brocks little hang glider. Nordic gliders have a stabilizer and elevator in the normal rear placement. Steve Murry copied the B6704-E almost dead on for his Alpine. Murry put reflex only outboard on the Alpine. Klass Hill indicated that he was exposed to the B6704-E from flying Nordics and we also see that he may have modified it, but he copied Murray in using unreflexed sections in his root and midspan of the Fledge2. So I am placing a large model sailplane airfoil on a small ultralight sailplane. Two aircraft that operate with overlapping flight ranges.
I'm not building a BUG glider-I've already built a primary/secondary glider, a 1930's repro. As far as I know no one has yet to complete a Bird Glider or one ever flown. Maybe one has actually flown by now-it doesn't matter I'm not building a Bird Glider. I do welcome the inputs but-I'm building a Quicksilver---- Quick-Silver, the only hang glider that you can get replacements for most of the parts 45 years latter. I'm not going to have to build the whole tail group- just buy it! If I wanted a QS C I could buy the entire bird except the root tube! I think I might have to make two wires too.
When I convert to ultralight tow glider I don't want a unicycle, I don't want a taildragger, I don't want a drop cart ( I may play with that before I trike it though) I 'm going to need my wheels at the end of the flight, and my balloon tires, and my shocks (mountain bike springs and dampeners, very light) not to mention the steerable nose wheel and breaks. I don't want the latest just been put out stuff, I want 45 years of tested with 10's of thousands of units flying world wide with decades and decades of technical updates! I don't know what may be wrong with the other gliders but what was wrong with a Quicksilver has been found, and the corrective measures have been created, and tested, 10's of thousands of units worth! 4 changes to the HG phase of this project is enough-I want to leave Dave Cronk and Ronny Richards to do the rest of the work Bob Lovejoy started.
Rick Masters is right, a twisted reflexed wing is second best- that's why what I'm proposing is not a twisted reflexed wing-it's not a flying wing airfoil-it's a model sailplane airfoil, and it's a champ many times over-model sailplanes that are bigger than some hang gliders! I've looked at Eiffle, Eppler, USA, NACA and more and I didn't pull the [ B6704-E KH mod 1] out of a hat. Furthermore why is it that glider people think that each design MUST BE THE ABSOLUTE HIGHEST PERFORMANCE POSSIBLE or your work is held in contempt? If I wanted that I'd dope an Eiffle, yes the oldest of them all and still hard to beat-just like the B6704-E. So please, I have put a little time and thought into this, about 40 years on the QS Fledge 2 part and 55 years into glider design and building.
As for TJW---thank you for the full scale drawings and all your help on this project.
If any one has a connection to Dave Cronk please PM me if so.
PS- if you you wish to see an example of a modern B6704-E modified airfoil set up your double surface rogallo and say DUH! Ground Slammer