Design > Engineering board
Twisted wing panel with correction tab - loss of lift?
Chuck_Smith:
--- Quote from: Dave Hull on March 05, 2021, 07:28:03 PM ---"This is an example of the engineering principle that other people’s disciplines are linear."
Boy, that one really hit the mark. One of my favorites was when an EE tried to explain to me (a mechanical engineer) how ball bearings work because he was worried that I didn't appreciate proper sizing and selection, etc. He wasn't really sure what the difference between a shield and a seal was. He was an excellent high voltage power supply designer, though....
--- End quote ---
Or a ME trying to explain a tilting pad & sleeve bearing to an aero guy!
Howard - interestingly, a flying wing doesn't require a reflexed airfoil if the wing sweep is correct. Ask the guys at Northrop. I was fascinated by the Northrop wings as an undergrad and studied them rigorously. I even have pieces of the B35 that crashed here in my desk as I type, along with some simple balsa gliders I built back in the day to prove the inherent stability of swept-wing tailless aircraft. You can toss them like a Frisbee and they almost instantly settle in to level flight. Also got some cool B2 memorabilia laying around here somewhere.
Serge_Krauss:
Chuck - just a FWIW...
The earliest successful swept-wing tailless aircraft (non-Zanonia-leaf types), as you probably know, were those of then Lieutenant J.W. Dunne. His wings achieved lift and stability configured as very thin sections wrapped about imaginary cones and cylinders, which created camber and wash-out needed on swept wings. He used to send these paper-airplane ideas to his friend H.G. Wells around 1903-8. Anyway his planes were among the earliest to fly in England. Full sized gliders were successful around 1906, and by 1910 he had achieved reliable powered flight with his "D-5." It was in that year that he made a famous flight demonstration in which he piloted the D-5, with virtually no experience (he had a heart condition), taking both hands off the stick to write each maneuver on a piece of paper given to him by Griffith Brewer of the Royal aeronautical Society and then descended with both hands in the air until just before flaring for landing. Representatives of the R.A.S. and Orville Wright witnessed the demonstration.
So, with an extremely thin but cambered wing, he built the first successful single-swept tailless plane. Starling Burgess used his patents to build several Dunne types in America during the war, improving the wing sections and adapting them to use as sea planes. However, WW I increased the performance of what became conventional (aft-tailed) aircraft immensely, leaving his designs behind. As we know, Lippisch, Hill, the Hortens and Northrop, among others, later built high-performance swept-wing tailless aircraft, and other low-aspect-ratio sorts also flew successfully. But none illustrated your statement better than Dunne's, whose wings had arcs for camber.
The pictures (my scanner needs replacing) below are from the "Aeronautical Journal" (later the 'Journal of the Royal Aeronautical Society') and "Flight." 'just an historical footnote.
SK
Tim Wescott:
--- Quote from: Dave Hull on March 05, 2021, 07:28:03 PM ---"This is an example of the engineering principle that other people’s disciplines are linear."
Boy, that one really hit the mark. One of my favorites was when an EE tried to explain to me (a mechanical engineer) how ball bearings work because he was worried that I didn't appreciate proper sizing and selection, etc. He wasn't really sure what the difference between a shield and a seal was. He was an excellent high voltage power supply designer, though....
--- End quote ---
Ball bearings work because I tell the ME's why they need to make the changes I'm asking for, then they laugh at me and go off and make totally different changes, and the assembly ends up working the way I wanted it to.
Chuck_Smith:
Serge,
Very cool stuff. I did a lot of research on the Horton Bros., including getting to see the Ho 229 years ago. I was at the Udvar-Hazy Center a few years back and to my surprise, in the restoration center sat the 229! After languishing at Silver Hill for so many decades it's hopefully finally going to get the spa treatment it deserves.
When I was an undergrad I was sure flying wings had to be the way to go. Later on I got enlightened enough to understand their limitations. Heck, even birds have tails, If tailless was better evolution would have favored the pterosaurs, lol!
Chuck
Serge_Krauss:
Hi, Chuck -
Wow, I envy you for having been able to look in on that project! When I saw the Ho IX (8-229) at Silver Hill (1980's), it was in awful shape and getting no TLC. 'glad to hear some version of it will fly again. My material indicates that the Ho. IX V-2 seemed to fly well, until one was carelessly flown and destroyed. Tailless aircraft do fit in some niches, especially now that fly-by-wire can make lethal versions safe, but they have often not fit assigned tasks. The Horten "bell-shaped" lift distribution might have let Northrop get by Mr. Symington with the bombers.
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