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Flying Wing : Scratch Design

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Albert Latham
Homebuilder or Craftsman
7
Posts
0
#1 Posted: 4/21/2010 11:04:14

I am currently unable to actually build anything, so I am testing myself with a thought puzzle. I am using this to familiarize myself with the fundamentals of aircraft design, both structural and aerodynamically.


DESIGN CRITERIA

Cruising Speed: 65 - 90mph

Endurance: 215 - 270 miles

Payload (minus pilot and fuel): 50lbs

Take-off roll: 100 - 200 feet

Landing roll: 100 - 200 feet



REFERENCES/INSPIRATION

Several things that separate this from the normal, run-of-the-mill aircraft design is that I want to use the flying wing planform. Pilot and passenger will fly prone and outside like the Wee Bee and others:

http://www.aerospaceweb.org/question/design/q0214.shtml

http://www.nurflugel.com/Nurflugel/n_o_d/weird_07.htm

The craft may utilize the "C" wing:

http://www.nurflugel.com/Nurflugel/n_o_d/weird_07.htm

http://aero.stanford.edu/Reports/Nonplanarwings/CWingTheory.html


I have been a long time lover of the flying wing concept. I have heard and read about several successful models, including the Davis Wing, the Horton Ho 229 and its predecessors, the Pul 10 and the H 3000, the WingCo Atlantica, the Facetmobile, and some others that I cannot rightly remember. Each of these upon a discrete inspection is somewhat shrouded in mystery and mystique; all of them are not well publicized or acknowledged.

Davis Wing:

http://members.cox.net/rebid/DavisWing.html

Horton Ho 229 (and others):

http://www.nurflugel.com/Nurflugel/Horten_Nurflugels/horten_nurflugels.html

WingCo Atlantica:

http://www.wingco.com/

Facetmobile:

http://www.facetmobile.com/

TOOLS

For the airfoil/exterior design portion of this mental exercise I will be utilizing several tools and online texts that I have stumbled across, here:

http://desktop.aero/appliedaero/preface/welcome.html

http://www.oriontechnologies.net/Documents/Airfoil.htm

http://www.zenithair.com/images/kit-data/ht.html

http://www.mh-aerotools.de/airfoils/flywing1.htm (I realize this is for models)

http://www.oriontechnologies.net/Documents/Airfoil.htm


If anyone has any other tools or technical references for this type of design effort I would greatly appreciate your links or input.

Because of my location books that I don't have on hand are out of the question (which means I need to stick to online references/tools/texts).

I would appreciate your input and thoughts on this puzzle I have put myself to. I will be running the preliminary calculations based on my desired numbers tonight. I will post my progress tomorrow. (In all practicality I would like to build a 1/2 scale model upon my return to the states just to see how my design efforts fare.)

Regards and thank you for your time,

-Albert Latham



Files Attachment(s):
Several views of the Wee Bee.jpeg (40925 bytes)
Weebee_draw.jpeg (22640 bytes)
Darrell Whiteaker
Homebuilder or Craftsman
14
Posts
1
#2 Posted: 4/21/2010 12:09:42

I've always loved the flying wings and tailless airplanes. I however don't think they end up being very practical. The prone position should be reconsidered. I don't believe you can lay in that position for any length of time and be confortable. Out of all the examples you list the DavisWing appeals to me the most.

Darrell

 



Michael Glasgow
Homebuilder or Craftsman
32
Posts
2
#3 Posted: 4/21/2010 23:01:46

 

A flying wing that exists and has some models flying is the Mitchell Wing.  I think most of the ones that are flying are using a trike with flight controls, rather than a hang glider type control frame like most trikes use.  I think the last owner of the design may have folded up, as the website for Ameriplanes doesn't come up, and the latest date I found of any conversation from the owner of Ameriplanes was in 2003. I didn't get very deep into my search about the Mitchell wing, so you might be able to glean some more information about it.  The Yahoo Group might be a good place to start.

Somewhere around 20 years ago, the Mitchell wing was being built in Kansas, maybe Hayes, and they were doing aircraft, kits, and plans, if I remember correctly.  It is an aluminum skin aircraft, but I'm not sure if the spars and ribs were aluminum or not.  I would think you would have better luck aerodynamically flying suspended below the wing, like a hang glider pilot, rather than laying on top of the airfoil, if you are wanting to fly in a prone position.  I have friends who are pretty deep into the competition end of hang gliding, who regularly fly 5 or 6 hours in a meet.  Another option would be to enclose a cockpit built into the upper surface of the wing, and sit in a supine position.  My interest in the Mitchell wing 20 years ago, was the hang glider version, rather than the powered version.  There is a Yahoo group for the Mitchell wing.  The Mitchell Wing Yahoo Group is here:  http://groups.yahoo.com/group/mitchellwing/


Long flights, smooth air, and soft landings,
Lincoln Ross
53
Posts
5
#4 Posted: 4/21/2010 23:39:47

Not quite sure why you want to use the flying wing here. Or, at least, the types you've referred to so far. And I'm not sure it's right to talk about  "the flying wing concept". There is a sort of flying wing that comes to mind, and that's the V-173 aka flying flapjack, prototype for a fighter. Although it's kind of overweight for your mission, it's one of the few aircraft which, according to reports, had the kind of takeoff and landing rolls you're talking about, and a top speed considerably greater than you require. However, the drawback is that you'd have to find a reliable way to drive those two props out at the edges of the aircraft. They're critical to this concept. Since you don't have to fly inverted, you may be able to get by with a better shape and less power. I'm thinking a long drive belt which drove both props might be good. You don't want one of the props to keep going if the other one isn't working.

I think you might find Zimmerman's patent for the V-173 interesting. Also, Zimmerman's two reports on "airfoils" (really wings) which can be found on ntrs.nasa.gov.   (try a search on his name, and the dates which are in the 1930's). Lots of other neat stuff at ntrs.

A delta wing might be something to consider, particularly since there's more documentation on them than the other low aspect ratio types, and more than for other flying wings too.

A tricky issue with a low aspect ratio aircraft like this is that the cheapo design software won't handle it correctly. I'm not sure what the solution for that is, particularly if you can't build anything. (Like a scale flying model, perhaps.) But I think it's one way to approach your "mission".

I'm not sure being on the outside of an aircraft going 90 mph would be very much fun. And it will cost lots of performance.

If your requirement for a flying wing was relaxed, you might be able to do this with a cleaned up, somewhat overpowered, conventional ultralight design. A lot easier to design one of those.

Your mission spec makes me think of the Colditz glider! You don't happen to be stuck someplace, do you? ;-p

 

BTW, some other downloadable tools you might find useful would be XFLR, Xfoil, Profili and Xplane (Xplane and the more useful version of Profili are not free, the others are). But as I mentioned, they may not be very accurate for a low aspect ratio aircraft.

 



Albert Latham
Homebuilder or Craftsman
7
Posts
0
#5 Posted: 4/22/2010 10:46:29
Darrel Whiteaker - Personally I've always loved the blended wing body and plain wing flying wings best. I think it's the simplicity (and subtle complexity) of the design that draws me. I have been thinking about the "prone" position and am beginning to agree with you. I have not-so-fond memories of lying in the snow during training...

Michael Glasgow - Supine would give wonderful upward visibility. I would be concerned that landing while in the supine position would be very difficult and a great strain to a neck. I'm beginning to think that a position similar to a "cruiser" motorcycle may be the way to go. Not yet sure on the ergonomics, though.

The other advantage of being suspended below the wing is ( ) Thank you for the link and reference to the Mitchell Wing. I will definitely look into it.

Lincoln Ross - The first reason I want to use the flying wing is because I love the planform in all of its variations; from delta to plank. I have read about the Vought V-173. That isn't quite what I'm looking for... The Facetmobile is ample proof that a super low aspect ratio plane does not need propellers on the wing tips.

I am open to pretty much all planforms right now so long as they are within the realm of flying wings (blended wing bodies count as well). I wish I could build something here, anything. But I can't. 

I put some thought into the specifications I posted above, and for a runabout there is no need to travel that fast. I have edited my first post accordingly (to reflect my 'new' specifications). I enjoy the wind in my face, but not for 2 hours at a time. The cockpit will probably wind up being semi-shielded with an option to fully shield the pilot.

As for stuck, yes. Yes I am. Afghanistan is hot this time of year, if you know what I mean.

Also, thank you for mentioning those tools, I greatly appreciate it! I will more than likely be utilizing those as this project progresses.

--

Based on the math shown in Chris Heintz's design college I have calculated the following:

Wing Area: 230 sq ft
Empty Weight: 350lbs
Gross Weight: 710lbs
Power Plant: Rotax 912UL (100bhp)

Cruising Speed: 250 mph (at 90% throttle) or 211mph (at 75% throttle)
Max Speed: 280 mph

Wing Loading: 3.1lbs per sq ft
Power Loading: 7.1lbs per bhp

What this tells me is that I need to shrink the engine by about 50bhp to get what I want. I'll run the numbers again tomorrow if I have time. Otherwise, this will make for a sprite little plane.

Regards, and thank you for your time,
-Albert Latham



Albert Latham
Homebuilder or Craftsman
7
Posts
0
#6 Posted: 4/22/2010 11:03:43

Apparently I cannot edit my first post. Here are the specifications I was attempting to edit:


Cruising Speed: 50 - 75mph [was 65 - 90mph]

Endurance: 100 - 200 miles [was 215 - 270 miles]

Payload (minus pilot and fuel): 50lbs

Take-off roll: 100 - 200 feet

Landing roll: 100 - 200 feet


And some tools I found today while working the math out.

http://web2.0calc.com/ - Scientific calculator capable of all low level calculations.


[thanks to Lincoln Ross for these]

http://xflr5.sourceforge.net/xflr5.htm

http://web.mit.edu/drela/Public/web/xfoil/

http://www.profili2.com/

http://www.x-plane.com/


Regards and thank you for your time,

-Albert Latham

 



Matthew Long
Homebuilder or Craftsman
122
Posts
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#7 Posted: 4/22/2010 17:27:35

Two suggestions:

You might want to look at Fauvel-type flying wings as an alternative to the swept-wing types:

  • http://www.nurflugel.com/Nurflugel/Fauvel/e_index.htm
  • http://www.marskeaircraft.com (Jim used to sell a nice little monograph on the history of his early flying wing designs, worth asking him if he still has any.)
  • http://www.continuo.com/marske/index.htm
  • http://www.foxpapa.com/spip.php?article910 (scroll down, it's in French, but great pics, use Google Translate if needed)

Expensive, but a useful resource is:

Tailless Aircraft in Theory and Practice by Karl Nickel

Cheers,

Matthew



******* Matthew Long www.cluttonfred.info
Andy Gamache
Homebuilder or Craftsman
122
Posts
28
#8 Posted: 4/22/2010 23:30:59

Hi Albert,

You can buy plans for the Mitchell Wing B-10 and U-2 here...

 

http://home.earthlink.net/~mitchellwing/index.html

 

Unfortunately, the last person associated with the design of the Mitchell Wings, Richard Avalon, died last year. His wife is selling the plans.

 

Probably won't finish for a few years since I'm in no real hurry, but I'm currently building a U-2. It looks like it'll meet most of your specs, except the prone and outside part, but I suppose you could do that if you want.



Ray Ordorica
Homebuilder or Craftsman
36
Posts
1
#9 Posted: 4/22/2010 23:50:33

 Hi, Albert,

A friend is building a Fauvel AV-222 motor glider. It is a two-seater, side-by-side, and you sit inside. He first built a model to prove the concept. The model failed miserably because the airfoil was wrong. But then he was able to get a computer program that allowed him to plot the correct airfoil full-size (dot-matrix printer), and from that he reduced the scale and built a second model with the correct airfoil. That second model was simply marvelous in flight. There was essentially no difference in performance or flight characteristics from normal models. I don't have any parameters for the airplane's performance, but best recollection is that they were very similar to yours. Good luck.

.......Ray



RayO
Matthew Long
Homebuilder or Craftsman
122
Posts
12
#10 Posted: 4/23/2010 07:26:39

If you are looking for library copies of flying wing plans as a learning tool, the San Diego Air & Space Museum archives include the Mitchell B-10 and U-2 plans and they will send you large-size photocopies for a modest fee.  See "Drawings" at http://www.aerospacemuseum.org/library/collections.html.  Cheers, Matthew



******* Matthew Long www.cluttonfred.info
Albert Latham
Homebuilder or Craftsman
7
Posts
0
#11 Posted: 4/23/2010 08:54:38

Matthew Long - Wow! I spent the first half of today reading through those links! That was fantastic! Thank you. As for the book you mention, I'm going to have to look pretty hard for it as Amazon doesn't have it in right now. Both Marske and Fauvel are extremely inspiring, and useful references.

Andy Gamache - That U-2 is quite something. I may spend the money so I can analyze the plans at a later date. Do you have pictures of your current build? That would be something I would love to see.

Ray Ordorica - I looked up the AV-222 which led me to the Nurflugel sight here: http://www.nurflugel.com/Nurflugel/Fauvel/e_AV222.htm

Well, airfoil is everything here because there are no tailing airfoils to balance the moments, or at least make them tolerable.

Matthew Long - To be honest, I would feel much more comfortable purchasing the plans from the widower of the last man related to the craft... Though, thank you for the link! I'm thinking I might be able to get plans from some of the other long abandoned wings.

As for progress made...

The math available from Chris Heintz I find to be somewhat lacking when it comes to useful specifications. Though I guess any foundation to start from is better than none. I'm going to have to come at this from another direction; I managed to find the specifications for the Wee Bee (mentioned in my first post). They are as follows:

--Specifications--

Wing Span: 18 ft

Wing Chord: 2 ft 5 in

Wing Area: 44 sq ft

Length: 14 ft 2 in

--Performance--

Empty Weight: 210lbs

Max Weight at Take Off: 410lbs (pilot and fuel)

Max Speed: 82 mph

Cruising Speed: 75mph

Range: 50 miles

Service Ceiling: 10,000 feet


The performance numbers for the Wee Bee fit the "mission profile" I want my aircraft to fill. One thing will be changed however (for a price payed in performance) is the range of the craft. I would like something with at least short legs on it so I was thinking somewhere in the neighborhood of 150 miles would be a reasonable distance to expect from a small flying wing coupled with the other performance specifications.

Regards, and thank you for your time,

-Albert Latham




Chuck Bodeen
Young Eagles Pilot or Volunteer
15
Posts
1
#12 Posted: 4/23/2010 09:20:37

Hi Albert,

I suggest that you download the "demo" version of the X-Plane simulator. In addition to x-plane.exe, you get airfoil-maker.exe and plane-maker.exe. You can use the last two to design your flyng wing and test fly it with x-plane.exe ... all without spending a cent! The only problem is that your joystick will stop working after a few minutes if you don't spend the $30 to buy the CDs.

Contact me at chuckbodeen@earthlink.net if you have any problems with the X-Plane package.

Chuck Bodeen, Panama City Beach, FL



Jim Heffelfinger
Homebuilder or Craftsman
256
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#13 Posted: 4/23/2010 22:58:03

look at this body of work\

http://www.continuo.com/marske/

 

http://www.marskeaircraft.com/

 

 

 



Albert Latham
Homebuilder or Craftsman
7
Posts
0
#14 Posted: 4/23/2010 23:20:36

Chuck Bodeen - Last I checked the X-Plane simulator could not realistically handle low aspect ratio or flying wing type aircraft. Also, because of my location downloading anything that large is out of the question due to my internet speed. I am on the equivalent of a 56k line. Maybe a little faster.

I also don't have a joystick.tongueout I'm pretty much unable to do any kind of flight testing simply because of my location and access/limits to materials and equipment.

Regards, and thank you for your time,

-Albert Latham



Albert Latham
Homebuilder or Craftsman
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#15 Posted: 4/23/2010 23:25:53

Jim Heffelfinger - Those links were already posted farther up the thread by Matthew Long. Thank you, though, for bringing those links to my attention again.



Sonja Englert
Homebuilder or Craftsman
18
Posts
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#16 Posted: 4/24/2010 12:33:21

I have participated in building a high performance flying wing glider, the SB-13 (Akaflieg Braunschweig) and also flew it. You can find pictures on the Akaflieg's website. There are many disadvantages to the flying wing concept and too few advantages. I have discussed this in my book "Homebuilt Aerodynamics and Flight Testing" (http:www.caro-engineering.com), based on my own experience. While the SB-13's performance was very good, it had some handling issues. They are the reason why, after several years of being flown in the group, the SB-13 now is retired and in a museum.

 

Sonja



Joanne Palmer
Young Eagles Pilot or VolunteerHomebuilder or Craftsman
276
Posts
68
#17 Posted: 4/24/2010 12:43:04

I'm with Sonja.  While lifting bodies and flying wings are great ideas, they're very unforgiving if you get them wrong in stability.  The B2 for example will not work very well if the computers are off line.  A lot of testing and mdeling should be done to determine the flight characteristics.  If you get it wrong these designs can bite.



Andy Gamache
Homebuilder or Craftsman
122
Posts
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#18 Posted: 4/24/2010 18:12:36
Albert Latham wrote:

Andy Gamache - That U-2 is quite something. I may spend the money so I can analyze the plans at a later date. Do you have pictures of your current build? That would be something I would love to see.


Unfortunately, there isn't much to show. I have a few ribs built, but I'm redoing all of them since I don't like the way they turned out. Here's a link to me building my first rib if you're interested. BTW... I work REAL fast in that video!!

 

There's a Yahoo! group called U-2Wing that you can join. There a bunch of pictures there. http://groups.yahoo.com/group/U-2Wing/

 

With luck, I should have all my trailing ribs done by the end of June.

 

Later!!

 

Andy



Dick Anderson
Homebuilder or Craftsman
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#19 Posted: 4/24/2010 19:11:04

Hi, Albert.

      First of all, thank you very much for your service and best of luck to you. I built and flew a Mitchell Wing B-10 (wooden wing) back in the '80's. At the time, it represented, to me anyway, the ultimate in looks, performance and "ease of construction" while remaining legal in the ultralight category. My 241 lb B-10 was overpowered with a 28 hp Rotax 277. The factory recommended the 20 hp Zenoah. I loved the way it flew, but it definitely required that the pilot learn different techniques to successfully fly it. Not difficult, just different if you are used to flying a Cessna. The design required that the pusher engine be mounted with a high thrust line so that in a stall, application of engine power would lower the nose assisting recovery. Having such a huge engine caused large pitch changes with any power adjustments. This is a characteristic common to pusher aircraft, even those that have a tail. Having a tractor engine would minimize even eliminate this problem. There have been some tractor engined low aspect ratio flying wings that might fit your design criteria- notably the ARUP from the '30's. Other similar designs include the Hoffman "Batwing" and Milt Hatfield's "Little Bird" series. There is an excellent article by Bernard Rice available as a reprint from issue 24 of Contact! magazine about these and other aircraft.



Dick Anderson
David Deweese
Young Eagles Pilot or VolunteerHomebuilder or Craftsman
61
Posts
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#20 Posted: 4/25/2010 09:32:58

That Fauvel av-222 looks much like the Alpaero Choucas:

http://alpaero.free.fr/choucas/english/index.htm

In fact they reference the av-221 and the Fauvel site http://www.survol.cjb.net/.

Maybe you can glean some information from those spots, I'm reviewing the English version of the Fauvel site even now.



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