NASA Prandtl Wing 1500mm RC model

[@dogdooish]

Remarkably stable, I'm a great fan of "Wings" !

[@samnelson3526]

Looks like the proverse yaw is working! I might have to try and make one of these... Super cool

[@smile768]

Well done! This is a really great job. Flies like a dream. The proverse yaw seems to be working because it turns well and there is no drifting of the nose in flight. I thought this design might 'change the world of aviation' because it is so revolutionary, but few people have made a working aircraft as of yet. You are in a very elite club!

[@thibautstilli5947]

Thank you :)

[@xnoreq]

This will never happen unless someone has money to burn because of the limitations of flying wing designs. The advantages are only theoretical. Commercial airplanes already have to use winglets because of constraints on wingspan. Implementing this design would require to increase span by roughly another 1/4th to achieve similar performance. But then you need a tail anyway for the load.

[@smile768]

@@xnoreq This Prandtl design is not a conventional flying wing, like the famous B-2, which has ‘clam shell’ drag rudders. (In reality the B-2 is cheating and is not rudderless, because the rudder is ‘baked in’ to the wing and requires fly by wire avionics to be controllable). The whole point of the Prandtl is that it doesn’t require a tail, doesn’t have wingtip vortices and needs no winglets. The tail on a conventional plane adds structural weight and downforce to balance the plane, as well as extra drag. Al Bowers claims efficiency savings of 50% or more by eliminating the tail and associated weight as well as vortex drag. Big claims yes, (I doubt 50% in the real world) but it would certainly improve efficiency. This new Prandtl wing would require a huge paradigm shift and I agree that the wing span would be troublesome for airport gates, so yes ‘money to burn’ type of investment for the industry. Folding winglets are emerging (777) so perhaps this could be worked out to shorten the wing. Airliners have changed little since the 707, but consider big weight and efficiency savings and this could be irresistible for the market.

[@xnoreq]

@@smile768 I know all that. And as I wrote wingspan is not the only problem. If you want to load hundreds of passengers and burn several tons of fuel then you need a wide enough controllable range for shifts in CG. This area is simply another weakness of flying wings that makes practical application difficult even if carefully designed. The claims by Al Bowers do not translate into practice. If you could just increase the wingspan then you could also significantly reduce induced drag using current designs. Removing the tail would result in maybe 20% gains, but these also shrink in more practical "tailless" designs.

[@xnoreq]

@@smile768 Another point you raised is development and advancements. There have been significant improvements resulting in higher fuel efficiency, lower emissions, noise, higher reliability etc. But even in this case it's all about the money. 300 to 400 million USD is not cheap, nor is training the pilots and all the other costs associated with switching to new models. We saw what happened with the 737 MAX, when Boeing tried to save money with a new design that allegedly doesn't require special pilot training, at the cost of hundreds of people's lives.

[@Shadismic]

The yaw looks so natural 💡

[@lucywucyyy]

i was planning on making my own prandtl wing glider from foamboard, seeing how well yours flies makes me definetly want to

[@SladkaPritomnost]

Nicely done, One day I will build something similar :) Thanks for sharing, very encouraging to see that bell spanload theory works even on simple model aircraft.

[@gordonquigg9389]

Awesome....

[@Bourne246]

great job! i wont be surprised if you didnt use any electronic stabilization. the plane flew very well.

[@ladislavsafarik8745]

Great work!!!!

[@davidandre8029]

Tcheu c'est beau la Suisse et bravo elle vole bien !

[@alterego2421]

Nice plane i also build one of those but with a 2 m span. Grüsse aus der schweiz

[@thibautstilli5947]

Thanks :-)

[@gunnarganz1130]

Ein Horten Nurflügel! Made in Gernany!

[@andreassittig2772]

Die Schränkungsverteilung ist komplexer als bei Horten. Schau Dir z.B. mal kzbin.info/www/bejne/rV7HnGSEpbuBhKs an. Also die Auslegung ist US-Amerikanisch. Und das Modell hier wurde von einem Schweizer gebaut: Fabriqué en Suisse.

[@lucywucyyy]

i think i can see the proverse yaw working in the fpv

[@cristiansandor4435]

This wing design is so stable without vertial fins and is not wobly at all. Good job! I will start working on a design like this myself. Can you please tell what is the thickness of the airfoils root and tip?

[@thibautstilli5947]

Hey thanks for your comment. I'ts was long time ago I was on this project ^^. I could not find easely the CAD file I used for this project. but anyway the 3D model, I based my design on is in the descricption. It's probaly way more acurate than "my semi-manual conversion" in order to to br able to work with fusion 360. From the top of my head I can say the tip thikness was around 6mm and the root one was about 24-28mm (for 1500mm wing span) but pleases verifiy with the 3D model, that was years ago ^^.

[@cristiansandor4435]

@@thibautstilli5947 I think I can concvert Sketcup file to STL or any other supported by Solidworks. Thanks

[@pascalfust1035]

Joli travail, félicitations. Je m'occupe actuellement aussi avec les performances aerodynamiques de l'aile Prandtl, mais j'essaye de diminuer le problème d'envergure... Est-ce que tu faisais tes vols en Allemagne ou en Suisse? Je remarque que tu commandes du materiel en Allemagne...

[@thibautstilli5947]

Merci :-) Non non en Suisse, juste que les détaillant ici, il y a quelques années, c'était Multiplex ou Graupner majoritairement ^^. Je sais qu'il existe des designs avec des aspect ratio différents qui traîne ici et là (que je serai malheureusement bien incapable de calculer moi même) , mais de pour ce que je comprends quoi qu'on fasse l'envergure sera de toute façon 25-30% plus grande qu'un design traditionnel avec winglet.

[@ericflighttester7145]

Well done, nice video. Did you find that putting the camera on top of your flying wing affected much the flight characteristics?

[@thibautstilli5947]

Thanks, I honestly dis not really try without, as the cg was good like that and I would have to cut the foam more to bring the battery forward If I wanna to remove the camera

[@gardentools2553]

I'm not having any luck with Dynamic soaring in fact I've got to wash in on the inboard tip and the speed is much greater ..turning right.. Prandtl not working.

[@edwardzeng3408]

Have you twisted(angle of attack) the wing based on the data sheet? I am also working on one but about 97cm wingspan, your’s looks much more flat than mine.

[@thibautstilli5947]

I used the 3d model, in the video description, I honnestly did not control all the mesurement with the NASA paper, but it was looking OK for me. Here a screenshot to give an Idea of the twist: i88.servimg.com/u/f88/12/08/39/64/twist10.jpg

[@edwardzeng3408]

@@thibautstilli5947 Thanks for your instant reply, by the way, where did you find the 3d model you are talking about?

[@thibautstilli5947]

@@edwardzeng3408 3dwarehouse.sketchup.com/model/8ca4115c-eab3-45fd-b644-80035f87d067/NASA-Prandtl-D

[@gasdive]

@@thibautstilli5947 it looks very like a hang glider wing except that the top of the chord (I've forgotten the right word) is much further back. The more usual shape of this wing has the centre of lift move back and forth too much with variations in AoA. That makes it pitch divergent in a hang glider, inducing tumbles in thermally air. (which can ruin your whole day).

[@RobMorse]

Do you know where you had the CG, or the degree of "elevator" deflection required to trim for level flight?

[@thibautstilli5947]

Hi, arround here: i88.servimg.com/u/f88/12/08/39/64/cg10.jpg ~130mm from the nose

[@rizen3467]

What camera did you use?

[@staho9796]

No Nasa ..Horten !

[@andreassittig2772]

Wing twist distribution is much more elaborated compared to Horten. See e.g. kzbin.info/www/bejne/rV7HnGSEpbuBhKs.

[@lowkateng153]

Can I know the place you buy the chinese cnc machine??

[@thibautstilli5947]

Hi, I ordered it on aliexpress, it was this one: fr.aliexpress.com/item/32811648830.html?spm=a2g0s.9042311.0.0.12ae6c37aSR3Cr Couple of things you need to know: -You will need a PC with a parallel port and a windows XP or windows 7 32 bit systeme to operate it. (it will not work with a 64 bit systeme). - The electronics is a complete crape, the fan die afet 3 days and the fuse sometime blow up by turnig it on (even with router off) - The motor tuning settings in the manual are wrong - Maybe you will have to fix the rigidity off the Z axis Basicly it's realy not plug and play, the machine is not perfect but the frame is heavy and strong, overall I think it worth the money if you are ready to mess arround for make it it work.

[@omnagar8225]

bro which cnc tip have u used

[@thibautstilli5947]

Hi, this kind: m.banggood.com/3_175mm-2-Flute-17mm-Carbide-Spiral-Bit-End-Mill-Router-CNC-Cutting-Tool-p-1038962.html?rmmds=search&act_poa=SKU329270&cur_warehouse=CN It's important for xps foam to go conventional milling and not climb milling

[@oegeat]

hello