my "vtol/ufo" idea

[planedude91]

well...i was watchin a TV show when this USAF plane came on...so i went to MS paint and made somethin like it....so here it is..

its a WORK IN PROGRESS!!

also...a poll to see if this would work...

the Sx control vents that allow/ restrict air flow out of 4 points...like the harrier..aound the rest of the ring there will be gaps that allow ait to flow evenly out... the props will be coax so it wont spin like a top...

tell me what u think!

alan :)

[Raketenflieger]

This is a "flying saucer" model it appears? For me, I need more than the one view to follow your idea....with the one view it is unclear to me.

Using two contra-rotating props would eliminate torque problems, yes. Give your idea a shot, and if it works...make sure to add plenty of BRIGHT LED lights on the thing, and fly it at night!! Maybe you can start up some local UFO rumors in your area, which would be cool! :)

[Terry S]

Yes, more info needed.
As it stands the props look too small but apart from that it seems possable.
Can you post some figures for it ?

Terry

[Tuner]

I completely understad this concept.

Thier is even another design out their nearly identicle to this only it incorporates some more advanced aerodynamic concepts to improve lift.

I will post it if I can find it. Very cool it uses a ducted fan but rather than relying entirely on the thrust produced by the fan as lift it directed the airflow over the entire top of the saucer. This creates a low pressure at the top of the saucer because the air at the top is moving faster than the air at the bottom just like an airfoil.

This design will work no problem but may be very sensitive to controls. Also unless you utilize the concept I descripted you will have a difficult time obtaining enough thrust from you Ducted Fan to lift the UFO.

P.S. Also you ducting will need to be more aerodynamicly designed.

Just my not so humble opinion.

[planedude91]

i made a "test bed" out of paper plates and a PC fan....it no work believe it or not...LOL any ways..i have vectron thing from walmart that i will mess with..

[avianaut]

Are you wanting to model this, by any chance? :rolleyes:

Avrocar (http://www.virtuallystrange.net/ufo/mufonontario/avro/avrocar.html)

Cheers.

[planedude91]

THATS WHAT I SAW ON THE AIR FORCE PROGRAM!!!!!

thanks for the link

[planedude91]

i attempted to make the ducts more aerodynamic..or however u spell it

the ducts are in light blue

[rhokita]

The 'real' Avro car flew less than .1 (diameter) in height. It was not a success... Perhaps a model with much higher thrust to weight ratio would fly better.

[avianaut]

I have to agree with Tuner and rhokita. I think you will need a very efficient airflow path from inlet to exhaust, and lotsa horsepower! I'd suggest get it airborne first, then worry about stability later.

From what I understand of the original, the fan pulled air from above, pushed it down and out to the perifery and down again at the exit. The exit air would have a kind of venturi effect to also pull air from above down around the edge. Thus two ways it reduces pressure above itself, which would seem to be efficient. In actuality it worked better as a hovercraft!

Now that you have a name for it do a search, there's more sites out there with info. Might help. Good luck.

Cheers.

[v22chap]

planedude91
Looks like a good challenge ,,keep us posted with your project :D
I saw an article some where of an electric twin prop being built and sold by some company ,,but can't remember who..??? Maybe hobby lobby ???? Any one know who ,,this would help you along so you don't have to reinvent the wheel

Larry

[planedude91]

ive done some thinkin... :eek: and what if i had 3 fans and used a CCPM system...so when u want to go up....the 3 motors work together and so on and so forth. just an idea that im throwin out there
:)

havent begun to build ne thing yet becuase my funds are toward my new rappy for now....but soon i would like to make a small test bed!!

[v22chap]

The other idea is more unique ,,but you will still have the problem of not enough lift from ducted fans ,,I think ,,but you will never know for sure unless you try it .

You might try 3 ducted airplane props ,,somewhat like what Tom Hunts vertigo uses and get enough lift and control . Read the prop fan versus ducted fan in this thread to see what Tom found out about ducted fans.
prop fan verses ducted fan (http://www.rcgroups.com/forums/showthread.php?t=508094&page=3)

Good luck and keep us posted on what you try
Larry

[Terry S]

Sounds good, but as v22chap says you need thrust not velocity so props or rotors would be better than DF.

[bladerunner12345]

check this out
http://jlnlabs.imars.com/gfsuav/index.htm

[v22chap]

Hey thanks for sharing ...looks a little unstable in hover ,but seems to do good in forward ... and it makes it up and down that constitutes success.
:D
Larry

[Tuner]

Thank You this is the other one I saw the Coanda affect. Though honestly I dont see why its an affect when it is no different than what happens with an airfoil faster moving air at the top makes vacume.

This is what I would make if I were to do a flying saucer.

Scott

[spinbotz]

That is one very awesome UFO. I may have to make one sometime.. Did he use Depron to make the body of the UFO?

[avianaut]

Tuner,

Someone might correct me on this, but I think the Coanda effect refers not so much to the fact that air moves faster on one side than the other, but more so the way in which this is made to occur. The Avrocar and NOTAR helis use the Coanda effect too, and they're not really airfoils.

That UAV should be easy to build, and you know it will work. Looks wierd, though!

Cheers.

[Langenase]

Thank You this is the other one I saw the Coanda affect. Though honestly I dont see why its an affect when it is no different than what happens with an airfoil faster moving air at the top makes vacume.

This is what I would make if I were to do a flying saucer.

Scott

"A stream of air alongside a curved surface that bends away from it still tends to follow the curvature of the surface". This is the Coanda effect

José Antonio

[Tuner]

Ahhh my comon sense combined with ignorance gave me a diffferent impression.

Thanks!

[FASTBEN]

check this out
http://jlnlabs.imars.com/gfsuav/index.htm
that is cool.

[Lemmiwinks]

"A stream of air alongside a curved surface that bends away from it still tends to follow the curvature of the surface". This is the Coanda effect

José Antonio

This is a viscous effect. All fluids exhibit this type of behavior to an extent. Calling it something else just makes an already difficult subject, aerodynamics, even more confusing...

[mnfiero]

This is a viscous effect. All fluids exhibit this type of behavior to an extent. Calling it something else just makes an already difficult subject, aerodynamics, even more confusing...

The Coanda Effect is a result of viscosity, not contradiction or misrepresentation. There is a lot of information out there to this affect.

The Aerodynamics of Golf Ball Flight
http://www.smcm.edu/nsm/physics/SMP03S/WarringK.pdf (from page 5)
"When a moving fluid comes into contact with a surface it will follow that surface. The tendency of fluids to follow a surface is the Coanda effect. This effect is largely due to the viscosity of air. Viscosity is the resistance of a material to change shape and form. Viscosity also produces the attraction between a fluid and surface."


Great Coanda Article
http://jef.raskincenter.org/published/coanda_effect.html

Some more Coanda info:
http://montalk.net/science/71/coanda-soliton-effect
http://www.americanantigravity.com/jetfan.html
http://jnaudin.free.fr/html/coanda.htm

[Langenase]

This is a viscous effect. All fluids exhibit this type of behavior to an extent. Calling it something else just makes an already difficult subject, aerodynamics, even more confusing...

Indeed Lemmiwinks. From now on I'll call Navier-Stokes equations "those :censored: numbers", and Bernouilli "Johnny", and so on, why not? :D

[iTs_jUst_sEth]

I took a min and edited one of your plans to incorporate a coanda effect. after researching a bit into the "vortex thruster"... i really believe with a little alteration like an impeller and a higher rpm motor- it WILL work. I have done some tests of my own vortex thruster and the coanda effect would be easy to master. i plan on building a vtol/ufo as well. did you ever get to a rc model? pics?

http://img.photobucket.com/albums/v315/x_seth_x/vtol2mod2.jpg

Although the coanda effect does NOT create a vacuum the flow will create separation and lift is an effect generated. Also the closer you can get to a proper vortex directly above the wing the better... I think you want a "mini tornado" directly above the impeller and a smooth transition for the output which goes directly over the wing surface.

[Stef]

The coanda effect does not produce a vacuum on the upper surface. The coanda effect bends the airflow around the curved surface of the craft and downward, it does not produce lift. If your prop and motor combo does not produce more thrust than your craft weighs it will not fly.

[TheKnife]

Just in case you haven't see it, you might want to read through this thread (http://www.rcgroups.com/forums/showthread.php?t=394375). The control mechanism is more heli-like that what you've proposed but you might find the other mechanisms of some use and/or interest.

[iTs_jUst_sEth]

Here is an interesting article that totally relates to this vtol idea...

http://img.photobucket.com/albums/v315/x_seth_x/AstroKinetics-Article.jpg


The article text in gifs...
Specs1 (http://img.photobucket.com/albums/v315/x_seth_x/Astro-V-Dynafan-text1.gif)

Continued.. (http://img.photobucket.com/albums/v315/x_seth_x/Astro-V-Dynafan-text2.gif)

Continued... (http://img.photobucket.com/albums/v315/x_seth_x/Astro-V-Dynafan-text3.gif)

Comments / info welcome

[planedude91]

THANKS!!!! that helps tons!

[iTs_jUst_sEth]

THANKS!!!! that helps tons!


np.. Im also interested in this method of vtol as it would make an awesome toy. Do you have any updates in your idea/plans? model? Anyway here is another pic I saved that I found some time ago... Someone somewhere back in the day built a flying model:

http://img.photobucket.com/albums/v315/x_seth_x/VTOL.jpg

I havent, though Ive searched found anything else on this pic or the model's builder. But 6ft dia is pretty big in my opinion.

So it looks like the technical stuff must be worked out.. But from my own research this "idea" is certainly possible. It seems after WWII there was secret research and development in the ufo shaped aircraft in the US and Russia left overs out of Germany... where it went I dont know... but maybe all the ufo sightings are really just human stuffs.. offtopic sorta but lends a little to the feasibility of your idea..

[planedude91]

im gonna scratch the foam single EDF design, and use the 3 motor one

[inventing_man]

It seems after WWII there was secret research and development in the ufo shaped aircraft in the US and Russia left overs out of Germany... where it went I dont know... but maybe all the ufo sightings are really just human stuffs.. offtopic sorta but lends a little to the feasibility of your idea..
Where it went was AREA 51 dream land. No big secret there.

[feralucce]

That project that you saw on tv eventually diverged into helis and Hover craft...

without control surfaces, it is going to be IMPOSSIBLE to control... the lift is adequate but unstable... they put a skirt on it and ir became a stable lift platform and it went on to be the modern hover craft...

Unless you do multiple engines, it is also gonna end up spinning without the friction that ground effect vehicles get

[planedude91]

its amazing what a bored kid can come up with....my latest idea.... enjoy

[djMidnight]

its amazing what a bored kid can come up with....my latest idea.... enjoy

That looks familiar - You should check this out: http://www.taileron.de/40211.html

It's all in german, but you can download pics & video, and he's got some good close-up shots.

[planedude91]

thats kinda where i got the idea :rolleyes: i was just tryin to make my rendition of it...i hope he doesn't patent it ;)

[feralucce]

how are you going to counter the instability?

[planedude91]

i would tie both of those images together.. so having the full moveable fan as the main one, then the 2 out board ones as they are

[TheKnife]

how are you going to counter the instability?

Yeah, I'm a bit curious about that myself. Without at least 1 EDF swiveling in a side-side fashion it's not obvious to me how it'll hover. All 3 EDFs seem to rotate fore-aft only. That said, the German guy's model works quite well. :confused:

EDIT: Thrust angles perhaps ? Are both rear EDFs vertically aligned or to they point in/out a bit ?

[planedude91]

im gonna go off of that one now. ill try to answer any questions :rolleyes:

[djMidnight]

EDIT: Thrust angles perhaps ? Are both rear EDFs vertically aligned or to they point in/out a bit ?

They don't need to move side to side - If you have the left & right EDFs pointing slightly different directions (IE, one slightly more forward than the other) the difference will cause yaw. Throttle differential on top of that is enough to get aileron / elevator control. It's the same as the tri-copter more or less, but with the ability to rotate the motors into forward flight.

Jason

[TheKnife]

They don't need to move side to side - If you have the left & right EDFs pointing slightly different directions (IE, one slightly more forward than the other) the difference will cause yaw. Throttle differential on top of that is enough to get aileron / elevator control. It's the same as the tri-copter more or less, but with the ability to rotate the motors into forward flight.

Jason

Oh now I see ! They move independantly. [slap_self_side_of_head] Doh. :p So if there's any roll to be compensated for, 1 side speeds up. This unbalances the torques (assuming they were balanced before) and the vehicle now wants to yaw. Moving 1 (or both) rear EDFs independantly will vector some thrust to counteract the yaw given it (they) are then speeded up a wee bit more to account for the new thrust angle.

[frankenfoamy]

Don't see how this would work with out gyro controlled thrust.
If you have gyro controlled thrust, you would not need the servos to control attitude. They would be for translation to forward ( convential flight)
Otherwise they would need to be two axis gymbaled. This would give better yaw control than thrust control only.

[planedude91]

if you want me to change anything in my plan.. let me know.. suggestions are welcome!!! :)