Thermaling a Fying Wing?

[Aceshigh84]

I am planning on contructing a ~60" flying wing glider out of fan fold foam and fiberglass for some soaring. As if it wern't hard enough to understand, find and tame a thermal, exactly how would I go about it for a flying wing plan form. There is not long tail to indicate sudden change in pitch. Just wondering if anyone has had some experience. Thanks

[SoarNeck]

Check out some of the million or so articles at www.b2streamlines.com

Bound to be something useful there. A big thermal wing is definitely on my list of future projects as well!

[fprintf]

I have tried building a 60" wing glider out of fan fold foam called the Zaginutz. I built mine using Profili and Dr. Drela's airfoils.I put a tow hook on the front of it and tried to histart it. It was lousy because fan fold foam is fine for an electric plane with small CF rods, but I needed to use a substantial CF arrow shaft to withstand the launching loads. It launched OK, about 50% of what a regular plane will do, but then was very difficult to see whether I was in lift. Most flights were 1 minute or less affairs.

I have now taken the plane apart and am reassembling it for slope duty only. I am glad I wasted my time on this experiment only to discover what I had already been told: a good thermaling wing needs to have a very light wingloading and to get that light wingloading with fan fold you need to have a fat chord, which ends up being less than optimum for thermaling. Catch-22.

[dephela]

You need area to keep the loading light. An increase in size and aspect ratio will increase area, improve efficiency. Torsional rigidity is the problem with a swept design. I haven't seen many "planks" designed for thermal yet but I bet we see a few coming out now that they're popular for DSing. A few are already used for HL/SALG. Launch height, lack of visibility, they tell me are problems.

What's been working, from Andy Macdonalds site:
http://www.glide.net.au/flyingwing/hjpage.htm

[Aceshigh84]

Thanks for the info. Actually I had been planning on using a carbon arow shaft for the main spar. And to tell you the truth I was going to setup it up to be discus launched. I did a couple preliminary models in solid works and the airframe weight is gona come in around 10-14 ounces depending on how much fiberglass i choose to use. The preliminary planform is sporting about 600 sq in of area. When i get a working one done I will publish some plans or something. Who knows, maybe it will work.

[Ollie]

R/CSD
http://www.b2streamlines.com/RCSD.html
Download PDF's.
Diva, Part 1, 03/9 to Part 5, 04/8

http://www.b2streamlines.com/OTW.html
PDF document describing our 1/4 scale Pioneer II-D.
A four part series on the construction of a modified Model Builder* Raven.
Our seventh Blackbird, a two meter version, is the subject of this construction series.
The Blackbird XC.3 two-part construction series.

[Ollie]

More......
http://www.aerodesign.de/modelle/NF/niveau2.htm
http://www.aerodesign.de/modelle/NF/phoenix.htm
http://www.glide.net.au/flyingwing/hjpage.htm
http://perso.wanadoo.fr/scherrer/matthieu/english/modelie.html#p1
http://www.aerodesign.de/english/profile/profile_s.htm
http://www.b2streamlines.com/Culver.html

[rdwoebke]

I have a lot of experience thermalling Red Herrings (and the Chinook). I have owned 5 of them, and have had a 10 minute + flight, a number of 5s, and a ton of 1 minute + flights. This is a hand launch (tip launch) and I would get about 45 seconds of "dead air" type time on my hand launches.

For me, these little Herrings did the best in strong tight lift. With a rearward CG, and the proper throws the things would turn on a dime.

So far as indicating lift goes, I admit, flying wings don't have some of the indication methods that their tailed counterparts have. But since I was flying HLG with them, it gave me a great opportunity to hone wind change/direction change reading skills.

Ryan

[Sparky Paul]

Wings generally launch better with dual tow-hooks, spaced off-center, since they have no tail end for yaw control on tow.
Other than that, there's only the visibility-orientation problem at altitude.

[averen]

Have you seen the CO5?
http://www.thehelix.com/soaring/CO5.html

Not fan fold...or glass...mainly EPS and Carbon...but you migh tget some ideas...

Jared

[surfimp]

I thermal my Weasel on the slope all the time. Flying wings are fine for thermal flying so long as the conditions are sufficient. I don't presume that one would outperform a true thermal ship but it is very doable and probably done somewhere in the world every day of the year. Good luck with your project and have fun!

Steve

[thermal]

I've read of some people flying the Unicorn (a 48 inch electric wing) getting them up to altitude and then turning the motor off and being able to thermal when the conditions are right.

Sounds like fun to me,
Bob

[dustn]

this plane is coming along nicely! i'm amazed how straight he got it considering its made of split Owens Corning pink and 60" span! its hangin on my wall right now... :P

[Aceshigh84]

Getting closer to the finish line. Last night Dustn and I built the twin tails and got everything laid up and resined. In addition to the internal arrow shaft it has a strip of thin unidirectional carbon fiber extending the length of wings top and bottom. It has kevlar and fiberglass around the throwing peg area since this will hopefully be a dlg. All that is left it to attach the elevons and install the electronics.

[averen]

pics?

[Aceshigh84]

I will get pics posted as soon as I can get my hands on a digital camera. They are kicking us out of the dorms over christmas so I don't know when that will be.

[dustn]

we can steal patrick's camera...

[Peytr]

Have you considered the Schiski?

http://leinauer.de/aero/schiski/

Most planks are not much good in flat land thermal flying. Slope lift doesn't count in my rulebook of thermal flying :). In general they can have very nice glide angles but the descent rate isn't too good, compared to conventional planes.

The Schiski somehow looks like a nice proposition to me. It's somewhere on my list but didn't try it yet. Go for low wing loading and possibly a high lift section. There aren't too many high lift reflexed sections so the JWL seems a good idea as well