Flying Wing Aircraft: Hand Launch Climb Necessity?

[Cashlover123]

Is a horizontal tail really necessary for climb on a flying wing if it was to be hand launched?

 

[Danger]

Flying wings don't actually use a "tail" at all. They have flight surfaces called "elevons" on the trailing edge. Depending upon how they are deployed, they act as ailerons and/or elevators.

 

[Dr Lots-o'watts]

I thought flying wings had so little longitudinal stability that they needed feedback electronics to control those "elevons". I'm not much into alternative aircraft design, but I'd be surprised to see a hand-sized flying wing stable enough for sustained flight.

 

[Danger]

I thought flying wings had so little longitudinal stability that they needed feedback electronics to control those "elevons".

The Vulcan bomber first flew in 1952, without the benefit of flight stabilization systems. Saab's Viggens and Drakens also utilized the delta platform, as have many others. While a delta is not exactly a "flying wing", the rear end is pretty much the same. Both do utilize vertical stabilizers (or stabilators as in the case of the Beech Bonanza and some military craft). I know that the Bonanza wasn't a delta, but used it as a reference to the stabilator configuration.

 

[Andre]

Is a horizontal tail really necessary for climb on a flying wing if it was to be hand launched?

No but indeed it's all about stability

http://www.clker.com/clipart-4601.html

 

[Dr Lots-o'watts]

The Vulcan bomber first flew in 1952, without the benefit of flight stabilization systems. Saab's Viggens and Drakens also utilized the delta platform, as have many others. While a delta is not exactly a "flying wing", the rear end is pretty much the same. Both do utilize vertical stabilizers (or stabilators as in the case of the Beech Bonanza and some military craft). I know that the Bonanza wasn't a delta, but used it as a reference to the stabilator configuration.

Ok, but by flying wing, I usually imagine shorter planes. The ones you mention are longer than they are wide, which does help longitudinal stability. The B-2 is a flying wing that I think stabilizers are controlled electronically.

My point is that I don't think there are any small-scale flying wings. If so, I'd like to see one.

 

[Danger]

Ah, I see your point, Doc. True flying wings, however, have been in operation since long before any sort of flight electronics were available. The first couple, in fact, were gliders, which bodes well for the success of a hand-launched model.
I'm going to quote a section of the Wikipedia article here, and leave it to the Mentors to determine whether or not it constitutes a violation of copyright.
Early examples of true flying wings include:
The French Charles Fauvel designed the AV3 glider, successfully flown in 1933,[3] featuring a self-stabilizing airfoil on a straight wing.[citation needed]
The German Horten H1 glider flown with partial success in 1933, and the subsequent H2 flown successfully in both glider and powered variants.[4]
The American Freel Flying Wing glider flown in 1937.[citation needed]
The American Northrop N-1M of 1940[5]
The British Armstrong Whitworth A.W.52G of 1944, a glider test bed[6] for the later Armstrong Whitworth A.W.52 jet-powered version.[7]
The German Horten Ho 229 of 1945 - the world's first twin jet engine pure flying wing

There's a lot more in the article, which might be of interest, and a lot more than that available on several other sites which Google readily conjures up.

 

[Borek]

https://www.youtube.com/watch?v=WnJYkzh9kTU

 

[Danger]

Cool video, Borek. Thanks.
It's kind of weird that I get just as much of a kick out of watching RC planes as I do the real thing.

 

[Dr Lots-o'watts]

Thanks Borek. I'm impressed. I'll have to look into this more.

 

[Wetmelon]

Nice video! And quite the landing hehe. "oh, that sucks." And it seems the answer to your question is "no, it doesn't need one."

P.s. Danger, your sig makes me chuckle every time I see it.

 

[Cashlover123]

Flying wings don't actually use a "tail" at all. They have flight surfaces called "elevons" on the trailing edge. Depending upon how they are deployed, they act as ailerons and/or elevators.

Then how about the rudder for it, how does it yaw?

 

[Cashlover123]

https://www.youtube.com/watch?v=WnJYkzh9kTU

that really is cool post you had... thanks!

 

[Cashlover123]

any estimates on how much thrust can be produced with a 3/4lbs of battery, and 20amps current??

 

[Danger]

Then how about the rudder for it, how does it yaw?

I should have been more specific in that post, but I did elaborate upon it in a later one. The first time, I was referring to what one normally thinks of as the "tail section" which usually encompasses both vertical and horizontal stabilizers along with the elevators and rudder(s). Deltas and flying wings use either regular vertical stabilizers or "stabilators" which combine the functions of rudders and elevators.

 

[john.phillip]

These are RC hand launched gliders:

 

[Danger]

Those are neat videos as well, John. While I don't know much about either gliders or RC models, I rather suspect that those are some highly talented operators. Unfortunately, the camera work made me a bit... not nauseated, exactly, but somewhat discomfited. I liked the music, though, so it was all good in the long run.

 

[john.phillip]

Ops, sorry about the ride.

 

[Danger]

No worries.

 

[dtango]

These are RC hand launched gliders:

Wow! Spectacular flying of those gliders especially in the 2nd video! Thanks for sharing. There must be some serious ridge lift on the side of cliff there where they are flying to be able to gain as much altitude and energy to perform the maneuvers they do.

 

[john.phillip]

Not exactly, load the second video and seek to 01:44, look carefully at the glider, what do you see ?

Please, continue reading this post after you did that.

In the first video you can see the delta gliders soaring, and feel their instability under low speed, which is expected. Danger might add we can feel the camera instability also, but I'm sure you can take them apart. If they are not careful, after some time they often will have to recover their gliders on the beach below.

On the second video, the little thing you see at 01:44 can be turned on and off remotely, so it adds launch speed and climb rate to the glider. With this extra energy they can make those fast high skilled maneuvers you saw, but they also can turn it off and enjoy the wind.

 

[Cashlover123]

Thanks a lot guys for all your tremendous effort and replying back...:).

 

[Cashlover123]

anyone have any idea what kind of airfoils are good for flying wings?.. I'm pretty sure you can't just use any airfoils for flying wings..

 

[viscousflow]

Highly cambered laminar flow airfoils, with the aerodynamic center pretty far aft.

 

[Cashlover123]

i thought so too but i wanted to know about some specific airfoils... which are commonly used and are easy to find data of... thanks..