Combined Hovercraft and Helicopter

An anonymous reader writes "Has British engineer Geoff Hatton brought us the best of two worlds with his UFO-looking machine? The US military thinks so and are investing in it. The design is sturdy (as opposed to a helicopter) and can fly high (as opposed to a hovercraft). It is based on the Coanda Effect."

Comments

sturdy? as opposed to a helicopter?

[lecithin]

I know the Marines still have CH-46 helicopters in service that took battle damage in Vietnam. Some are 40 years + and none are less than 35 years old.

Saying "The design is sturdy (as opposed to a helicopter)" is really quite a statement since the design is not in service.

Seems pretty cool though.

Re:sturdy? as opposed to a helicopter?

[localroger]

How many of those helicopters that are still flying were flown a wall at any point during their service life?

Re:sturdy? as opposed to a helicopter?

[MindStalker]

He is referring to its ability to handle midair crashes. Of course a larger version would probably handle midair crashes about as well as anything else..

Re:sturdy? as opposed to a helicopter?

[Hijacked Public]

I think they base that primarily on the fact that the rotor is protected. Many helicopters can take hits in non-critical areas but a rotor strike is almost always catastrophic.

Re:sturdy? as opposed to a helicopter?

[bohemian72]

Well, they mean sturdy as it can bump off a wall without tearing up a main rotor and crashing.

Re:sturdy? as opposed to a helicopter?

[forrestt]

What they are saying is that the hovercopter (for lack of a better term) has the rotors protected and can bump into things and still fly. What it basically is is a small inverted squarish bowl with a fan on top that forces air down and around the sides. The fan is protected and therefore, more stable. It is controlled with fins that direct the downward air in various directions for steering. This isn't being designed for movement of people or cargo, but rather as a means to carry a small camera for recon missions. (think the small machines sent out by Skynet in the Terminator movies).

Re:sturdy? as opposed to a helicopter?

[Anonymous Coward]

I think its referring to how helicopters require sophisticated electronics and pilot skill to remain stable in flight. This concept supposedly allows for easy air stability.

Re:sturdy? as opposed to a helicopter?

[mstahl]

Maybe they meant "stable"? That doesn't really make a lot of sense either. . . .

Re:sturdy? as opposed to a helicopter?

[The Orange Mage]

The article means "stable: as in it isn't subject to the "touchiness" that helicopters have. Essentially, tighter handling. Plus you can bump it into stuff and it won't die instantly.

Re:sturdy? as opposed to a helicopter?

[drinkypoo]

They won't be much larger, or made out of much more durable materials (they can be flexible) because they are planning to use them as UAVs and not as manned aircraft, at least for the time being. If you RTFA they specifically talk about the design's suitability for this purpose in light of its ability to survive collisions with walls.

I'm afraid I'm going to dream of manhacks tonight...

Re:sturdy? as opposed to a helicopter?

[modecx]

He is referring to its ability to handle midair crashes

I don't think that's what he's referring to at all. Helicopters are very unstable machines, especially in hover mode, which is arguably the most important and most distinguishing feature of a helicopter. A helicopter requires hundreds of very precise control inputs a minute to remain in a hover. If you change one of the variables, you pretty much have to change all of the rest. For example, if you adjust the cyclic, you have to adjust your engine's torque and collective a tiny amount so you don't fall out of the sky, or alternatively, go flying up too fast, and you'll also have to nudge the tail rotor to account for the increased torque form the main rotor. You can think of it as a loop in a computer program that operates very quickly.

It looks like this guy's hovering craft aims to make the most advantageous feature of a helicopter much, much easier to preform, and hence the vehicle is "more stable" than a helicopter. It's probably more sturdy, too, but that's a side effect of not having blades swinging around in an arc that is considerably larger than the aircraft.

Re:sturdy? as opposed to a helicopter?

[Anonymous Coward]

Not only is the rotor protected, it also doesn't extend beyond the edge of the non-moving parts, making it very unlikely that something bumping into the device would come close to the rotor cage. I'd like to see some fluid dynamics simulations of an obstruction on one side of the "wing" though.

Re:sturdy? as opposed to a helicopter?

[Anonymous Coward]

Even a well designed helicopter like the CH-46 needs tonnes-o-maintenance. Changing the pitch of the blades puts huge amounts of stress on the rotor, causing lots of normal wear and tear. This guy's model puts the control surfaces on the outside of the convex surface, meaning the blades are just a simple prop - no more need to precisely control parts that are also whizzing around at a zillion rpm. I'd guess that if this vehicle were comparable to a helicopter in performance (which it isn't yet, and may never be), it would be superior by being able to operate longer between maintenance and needing fewer parts. So yes - more sturdy.

Re:sturdy? as opposed to a helicopter?

[lonechicken]

(think the small machines sent out by Skynet in the Terminator movies). Ah, the always trustworthy and benevolent Skynet.

Re:sturdy? as opposed to a helicopter?

[Profane MuthaFucka]

There are two more things which you didn't mention. One is that the fan is inside a duct, which reduces tip vortices. That should make it more efficient.

The second is that it would avoid a problem which helecopters face when trying to hover out of ground effect. When more than about a rotor's diameter above the ground, the downward moving air starts to circulate down, out, up, and back into the rotor. The air moves in a circular pattern through the rotor, around, and back through the rotor again. This creates a downdraft from the perspective of the helecopter. Adding more power doesn't always help, because it just makes the air move in a circular pattern faster. The result is that the helecopter sinks when trying to hover at altitude.

If you observe helecopters hovering at altitude, you'll notice that they aren't actually hovering. They're moving forward very slowly. That's the only way to avoid that problem. You have to keep moving a little bit so you stay out of the circular rotation of air that you create behind your helecopter. If you stop completely, you're in the circular pattern and you sink unless you've got some enormous power source like a jet engine.

When you're in ground effect, the ground itself disrupts the circular movement of the air and limits how fast it can move in a circular motion. It also makes it turbulent as it deflects off the ground. The result is that you don't get a well-formed column of downward moving air that your helecopter is sitting in, thus you can efficiently hover without moving at all when you are fairly close to the ground or some other air-disrupting object like a building that you're carrying materials up to.

I would not be surprised if this device had some advantages over regular helecopters when it comes to hovering out of ground effect.

Re:sturdy? as opposed to a helicopter?

[drinkypoo]

I've heard that some of our attack helicopters can lose significant percentages of the rotor surface and still stay aloft, specifically the Apache and the Comanche (project abandoned once it was complete, your tax dollars at work.) Was I lied to? :)

Re:sturdy? as opposed to a helicopter?

[Moofie]

You bump your CH-46 into a wall, and then tell me how durable it is.

Obviously, we're comparing apples and oranges here, but I wouldn't call ANY helicopter a "rugged" design. Reliable? Sure. Rugged? Maybe not.

With the possible exception of the MI-24 Hind.

Re:sturdy? as opposed to a helicopter?

[Jaysyn]

Better than mansacks, right? :D

Re:sturdy? as opposed to a helicopter?

[mpaulsen]

R44 crashes into the hangar door http://youtube.com/watch?v=pXFdMDDYGOA

Re:sturdy? as opposed to a helicopter?

[drinkypoo]

In terms of a dream? Probably. But the latter is less dangerous to be attacked by (I don't even have a crowbar!)

Re:sturdy? as opposed to a helicopter?

[BostonPilot]

I beg to differ - I think the parent was probably correct about what the author meant. First of all, the design did NOT look that stable. Also, the fact that the fan is ducted means gentle collisions won't destroy the rotor system which is a pretty good feature for a small UAV. It also has a safety benefit if the rotor is ducted.

As for the stability of helicopters, if you look at the designs in the 50's and 60s, stability was a big goal. Look at Stanley Hiller's demonstration of hands off hovering of his helicopters. Over the years stability appears to have been less and less of a goal. Look at how the flybar on the Bell rotor systems has disappeared. I'm not sure why this has happened, but I'm guessing that agility has won out over stability, especially since stability can easily be added by electronic means.

I read the article, but I wasn't quiet sure how the Coanda effect was utilized by this design. I'm guessing that rather than tilt the rotor there are places where the downwash is attached (or not) and thus generate sideways thrust? I saw the little vanes moving, but assumed that was more for anti-torque - if you noticed, most of the vanes were fixed with a little bend in the direction of anti-torque (and, like the MDHC Notar the anti-torque force would be proportional to downwash and thus to torque). A few of them moved to give you the ability to rotate the machine and account for minor yawing forces not exactly countered by the fixed vanes.

Did anyone else notice where/how Coanda effect was used? Perhaps the moving vanes really are implementing the Coanda effect, but if so it's in a fairly different way than the MDHC Notar system. Did I miss something?

Re:sturdy? as opposed to a helicopter?

[comp.sci]

The secret of keeping helicopters in action for years is that due to very frequent checks and tests, almost every part gets regularly replaced.
I talked to a air-rescue helicopter pilot once and he told me they have helicopters in service that are 35+ years old, but the only original parts in them are their skids.

Re:sturdy? as opposed to a helicopter?

[Anonymous Coward]

It is common for around 50% of the helicopters in a unit to be grounded for service. They push the limits of the materials they are made of, break down often, and are flown is less than 100% prime condition. A joke among some marine helicopter pilots is "If it ain't leaking (hydraulic fluid), don't fly it." Meaning if it isn't leaking fluids, that's because it's empty!

Re:sturdy? as opposed to a helicopter?

[Anonymous Coward]

It's true as far as I know. A rotor is just a wing that spins to get the air moving over the wing surface.

That said, however, it is definitely possible to unbalance the rotor when it's damaged, in which case it may quickly (depending on how unbalanced) shake itself apart.

But it's hardly like a little tiny knick or a bullet hole is going to make a helicopter fall out of the sky.

Re:sturdy? as opposed to a helicopter?

[inviolet]

The second is that it would avoid a problem which helecopters face when trying to hover out of ground effect. When more than about a rotor's diameter above the ground, the downward moving air starts to circulate down, out, up, and back into the rotor.

You are thinking of "vortex ring state"... the thing that played so much hell with the Osprey.

Conservatism is a failed ideology which has joined communism in the trash heap of history.

Odd. While I agree with the sentiment, I've always thought of conservatism as a state of mind (or rather a deferment to past minds) rather than as an ideology. I say this because I can see conservatism at work within many ideologies.

Re:sturdy? as opposed to a helicopter?

[Oktober Sunset]

I don't know about that but I do know the the Apache helicopter can't fire it's main hellfire anti tank missiles at close range because it risks blowing it's own rotors off from the shrapnel.

Re:sturdy? as opposed to a helicopter?

[drinkypoo]

Uh yeah, but that's a tank-killing missile. One hit generally kills a tank. If you fired that at close range, you might not just blow your rotors off, but yourself to kingdom come. In other news, suitcase nukes are best detonated with a timer...

Re:sturdy? as opposed to a helicopter?

[Oktober Sunset]

Close range for a helicopter means about the length of a football field (which, if you were flying low below radar, carrying out a ground attack, would be the kind of distance you might expect to be confronted by a tank), and armour piercing warheads are designed to direct the blast forwards to pentrate the armour, and minimise the back blast.

Considering a squishy little human being can usually survive a shrapnel hit to anywhere except a vital organ, an armoured war machine would usually be expected to do better.

Re:sturdy? as opposed to a helicopter?

[muffel]

I've heard that some of our attack helicopters can lose significant percentages of the rotor surface and still stay aloft, [...] Was I lied to?

Yes, you probably were.
Unless equally sized bits break off of every blade or a *very* small piece breaks off a blade, the helicopter is almost sure to immediately literally explode from the created imbalance. And that's not a joke.
Many RC-Helicopter pilots know this from own experience -- a loud bang and the helicopter rains down in pieces (and those blades only weigh ~150g).
Also a report of this happening to a real helicopter.

Re:sturdy? as opposed to a helicopter?

[dcam]

I've read ChickenHawk. In that he describes "chopping" his way out of jungle clearings using the rotors on a huey. So rotors can certainly take some damage. However it is still a relative weak point (weaker relative to other parts).

Re:sturdy? as opposed to a helicopter?

[iminplaya]

Not exactly sure, but I believe the problem arises when you get within the rotor's diameter above the ground. One reason they hover so high during search and rescue is to stay out of ground effect. When that air hits the ground, it has nowhere to go but out and then up due to the tip vortices to be sucked back into the rotor. If it were the other way around, these guys would have a heck of time putting those towers on top of the skyscrapers, seeing as they don't move too much...unless it's really windy. Note however that a helicopter can hover at a higher elevation in ground effect(mountain plateau for instance) than out of ground effect

Re:sturdy? as opposed to a helicopter?

[students]

iirc, Vietnam helicopters had their rotors replaced every few days if they flew in dusty conditions. I might have the wrong war there.

Re:sturdy? as opposed to a helicopter?

[sumdumass]

I don't think this is as big of a problem on modern system as it once was. Don't get me wrong, it still is an issue but I have seen pictures of rotors with bullet holes in them on helicopters that made it home from Iraq.

I have also seen pictures were a Bell( i think it was Bell) aircraft had a flock of birds fly into it causing some severe damage to the rotors and it was able to land safely in a field almost some five miles away.

They have done some really good work at isolating vibrations and keeping control mechanisms intact when they (rotors) become damaged.

Re:sturdy? as opposed to a helicopter?

[iminplaya]

The vanes inside the attached boundary layer simply direct the airflow to either side for what appears to be yaw control. I couldn't see them, but there's probably a set in "front" also. Movement is accomplished by the moving panels on the bottom. It appears to stay upright naturally.

Re:sturdy? as opposed to a helicopter?

[Sensible Clod]

The Coanda effect is used primarily by the whole outside surface of the craft. If you look at the top, you can see that although the fan produces downward forces, the air runs right into the solid top surface. From there, it would tend to go directly out to the sides, doing nothing for thrust (imagine attaching a fan to a box such that it's pointing at the box -- will it move if you turn it on?), BUT the surface is curved just so that the thrust remains attached to the surface, and is carried over and downward by the Coanda effect before it separates from the surface. This is what you were referring to when you said:

there are places where the downwash is attached

Keeping the downwash attached to the surface like that, going sideways, over and down, is the Coanda effect in action.

The Wikipedia article describes it as sort of like an inside-out hovercraft.

Re:sturdy? as opposed to a helicopter?

[SuseLover]

If you observe helecopters hovering at altitude, you'll notice that they aren't actually hovering. They're moving forward very slowly.

That would be news to the high voltage tower service pilot. I've watched as a helicopter hovered absolutely still (+/- 6-12") for over 5 minutes while a tech harnessed to the side and hanging down attaches the insulator on top of the tower in 30 mph wind.

Hovering uses the same fixed-wing aerodynamics as a plane with the tail rotor compensating for the torque against lift, the air stream must travel further over the top than below the wing (rotor) providing lift.

Re:sturdy? as opposed to a helicopter?

[John Hasler]

> That would be news to the high voltage tower service pilot. I've watched as a helicopter
> hovered absolutely still (+/- 6-12") for over 5 minutes while a tech harnessed to the
> side and hanging down attaches the insulator on top of the tower in 30 mph wind.

Hovering with respect to the ground in a 30mph wind is the same as moving 30mph in still air.

Re:sturdy? as opposed to a helicopter?

[modecx]

I fly R/C helicopters that are about the same size, and probably about the same mass as this aircraft, and I can say this: either the guys flying these aircraft were very competent, or that little thing was pretty damned stable. I'm inclined to say the latter. I've seen guys who make it look easy, but most of them have their choppers loaded up with all sorts of crazy sensors and computers that fly the chopper as much, if not more than they do... And it's not apparent to me that this craft had those sorts of electronics, and the craft appeared to correct itself naturally, and quickly.

The Coanda effect was used for the lift of craft. It made the flow of air go across those little flappies on the sides, and straight down after that, providing downward thrust. The little flappies are apparently the counter-torque mechanism, and the bigger flaps on the bottom of the craft appear to the method of control.

Re:sturdy? as opposed to a helicopter?

[Profane MuthaFucka]

What kind of helecopter was it? And how long did he have to hover there? And did his boss care that he was burning fuel at an amazing rate to get the job done?

Probably not. The boss probably wants him to burn the gas to the get the job done. On the other hand, the news chopper won't hover in a stationary position because he can save a shitload of gas by moving forwards a little bit. If he's in a jet copter, he'll have the power to do what he wants. But he might not want to burn the extra gas. If he's in a Robinson, his options are more limited for high altitude hover.

Re:sturdy? as opposed to a helicopter?

[Profane MuthaFucka]

COOL, I have a name for it. Thanks.

I've always thought of conservatism as a state of mind

I've been pimping my journal a lot lately, so why stop now. I think that's an insightful comment there, and you may find some interesting deep analysis of various political -isms in my journal. I have a unified theory of political moral identity. I just made that name up.

Re:sturdy? as opposed to a helicopter?

[DerekLyons]

Also, the fact that the fan is ducted means gentle collisions won't destroy the rotor system which is a pretty good feature for a small UAV.

Since the crafts stability depends on the airflow around the body - one wonders what a gentle collision will do to that airflow.
 
 

Did anyone else notice where/how Coanda effect was used?

To make the air flow down around the outside the body, rather than straight out where the fans exhaust hits the top of the craft. I imagine it also plays a role in the functioning of the body flaps at the base/rim of the craft.

Re:sturdy? as opposed to a helicopter?

[MichaelSmith]

It reminds me of the shell shaped hovercraft in Minority Report.

If this design can be made to scale I can see it working as a close in observation vehicle and troop carrier. If you have to manoever around power lines, bridges and buildings something like this should be a lot better.

I remember reading about a helicopter rescue in the water close to an oil rig. The helo lost IIRC 10cm of blade when it struck the rig and was lucky to survive.

Re:sturdy? as opposed to a helicopter?

[earthbound kid]

"35 years old," but only one pair of original parts is left on it? Sounds like the Philosopher's axe!

Re:sturdy? as opposed to a helicopter?

[swb]

A friend taking flying lessons said that FAA regulations required the chopper used at the flight school to have its engine completely rebuilt every 1000 flight hours. I'm sure that's probably not entirely accurate (my memory or her quote), but I'm sure they do require significant rebuild/replacement of major components really frequently.

Re:sturdy? as opposed to a helicopter?

[GooberToo]

You would be amazed at the number of Vietnam era aircraft which are still flying. I have flown on a CH-47 Chinook and noted odd textured/patches on most of the helicopters on the flight line. When I got off the helicopter, I asked my friend, who is a mechanic that works on them, why they were all patched. He laugh and said most of the helicopters saw action during Vietnam and that those were bullet holes which had been patched.

Re:sturdy? as opposed to a helicopter?

[GooberToo]

I can tell you that this is not true. Rotor imbalance is a serious problem for any helicopter. My brother is an instructor in Apache Longbows, so he knows.

(project abandoned once it was complete, your tax dollars at work.)

For what it's worth, my brother bunked with a pilot on that project. I had a chance to briefly talk with him about it. He agreed it wasn't what was promised but he could not go into details on it with me. At any rate, what most people don't realize is that the research from the project will resurface into another project down the road, so it's not totally wasted. The good news is, they didn't put it into production...that would have been a complete waste of tax dollars.

In fact, as I understand it, a new revision of the Longbow is now planned. I believe part of the avionics research from the Commanche project will directly feed back into the next revision of the Longbow.

Re:sturdy? as opposed to a helicopter?

[GooberToo]

One of the cool things an Apache Longbow does is settle into the treeline. They stop descending when the tops of the trees have been clipped by the main rotors. This allows them to remain hidden while they scan for targets. They then pick their targets (radar is above the rotor), pop up, fire, and go home. Some seconds later their targets are smoking.

Also, during Operation Anaconda in Afganistan, many Apaches returned home with many, many holes in their main rotors from small arms fire. The rotors can take a serious beating and still hold together. In fact, during that same operation, one Apache took a direct RPG hit in its transmission. It flew home despite the total lose of fluid. Another Apache took a direct RPG hit on its FLIR and it too returned home.

Despite how rugged it is, just don't turn on the rotor heat! The apache is suppose to be an all weather craft but the rotor heat is not suppose to be used because the blades will delaminate. :)

Re:sturdy? as opposed to a helicopter?

[drinkypoo]

They then pick their targets (radar is above the rotor), pop up, fire, and go home. Some seconds later their targets are smoking.

I thought hellfires were laser-guided. Don't they have to wait until the opponents are vapor above a crater before they go home?

Re:sturdy? as opposed to a helicopter?

[BostonPilot]

If it's as simple as this, I'm disappointed. How is the aircraft controlled in roll and pitch? Watching the aircraft fly, it appears that the operator is controlling the aircraft in pitch and roll, and perhaps in yaw. How? (it looks like the moving vanes would control yaw).

If the Coanda effect is simply being used to attach the flow around the surface of the craft, I don't see how pitch and roll control are maintained, nor how you would produce lateral displacements. The flow would be mostly uniform, and the craft would hover but not controllable in pitch and roll. Yet in the video, it certainly appears as if the operator is able to control the craft much as you would a helicopter.

I was assuming that some of the air is being ducted through a slot or something so that the flow could be attached in a non-uniform way around the body of the aircraft, and that these non-uniform flows would then result in different directions of thrust at various points around the craft, thus allowing pitch and roll control.

In the MDHC Notar, there is a jet of air which is forced out along one side of the tail boom, and this attaches the main rotor down wash to that side of the boom. If Coanda was just about the shape of the surface, MDHC would not have gone to all the trouble it did to pressurize air inside the tail boom - they would have simply built a tail boom with a specific shape.

I find the Wikipedia article a bit confusing. On the one hand, they define Coanda effect as:

Method and apparatus for deviation of a fluid into another fluid

and this is consistent with the MDHC usage of Coanda - they introduce one flow of air into another to attach the first flow. The Wikipedia article gives the example of the spoon in the flow of water. If the flow of water is the first fluid, where is the second fluid?

How is the spoon example different than what happens when air flows over an airfoil? Are we saying that is also an example of Coanda?

Re:sturdy? as opposed to a helicopter?

[GooberToo]

I thought hellfires were laser-guided. Don't they have to wait until the opponents are vapor above a crater before they go home?

I think you are thinking of the old TOWs, which are wire guided. The Hellfire missile is a fire and forget missile. Once it's launched, it independently seeks its target.

Re:sturdy? as opposed to a helicopter?

[Sensible Clod]

it appears that the operator is controlling the aircraft in pitch and roll, and perhaps in yaw. How? (it looks like the moving vanes would control yaw)

Yes, the small, black vanes are used to control yaw. If you look closely, you can see some yellow flaps on the bottom which control roll and pitch (what little there is). I don't know much about the Notar.

The Wikipedia article gives the example of the spoon in the flow of water. If the flow of water is the first fluid, where is the second fluid? How is the spoon example different than what happens when air flows over an airfoil? Are we saying that is also an example of Coanda?

The second fluid in the spoon example is the air. Both gases and liquids are fluids.

The spoon example is not much different than airflow over an airfoil. And yes, airfoils (such as wings) do indeed use the Coanda effect to take advantage of the Bernoulli principle to produce lift. If the air (or water, in the case of hydrofoils) didn't stick to the curved surface, it would be extremely difficult for them to produce any lift at all.

Maintenance?

[Turn-X Alphonse]

But how complex are these machines to maintain? War equipment needs to be bery quick to fix and and this sounds extremely complex.

Re:Maintenance?

[Anonymous Coward]

Doesn't look very hard. It's just one fan and some flaps. We pretty much have that technology down.

Re:Maintenance?

[brunascle]

take a look at the picture. looks pretty simple to me.

Re:Maintenance?

[jhfry]

I'm pretty confident that I could reproduce a semi functional (hover only) version of this in a weekend... damn device looks almost too simple to be new.

Re:Maintenance?

[the_wishbone]

FTA:

"'Unlike a helicopter, though, this is aerodynamically neutral and you can bump into walls and not smash the rotor,' said the inventor.

"And, unlike a hovercraft, you can fly it as high as you want.'

The dome-shaped object is powered by an electricity-driven propeller on top that pushes air over the outer surfaces, and has controllable flaps.
Geoff's Flying Saucers - the original name for his GFS Projects company - are based on an aerodynamic principle that has been around for nearly 100 years.

Known as the Coanda Effect, after a Romanian jet-engine pioneer, the principle is today used primarily in helicopters that have no tail rotors."

Sounds to me like it's even less complicated than a traditional helicopter. The blades in a traditional helicopter go through some incredibly complex motion. From the pictures in TFA, it looks to me like this is a simple propeller. Rather than relying on complicated mechanisms on the blades, it exploits the properties of the working fluid (air in this case). The adjustable flaps over that outer surface look simple enough.

Seems to me like a lot less complex, mechanically, than the helicopters we've been deploying to wars for decades.

Re:Maintenance?

[Jbcarpen]

Much of the cost involved in maintaining a helicopter is concentrated in the maintenance of the complex and fragile tilt rotor mechanism, something that this new vehicle does not have. Instead it has flaps around the edge which will be much less expensive to maintain.

With this design I would expect the costs to be closer to those of a fixed wing aircraft than those of a traditional helicopter.

Re:Maintenance?

[jandrese]

That's because it isn't new. The Avrocar was using a very similar system in the early 60s. While I'm sure the scale model pictured in the article has no trouble going up or down, I bet it has a lot of difficulty building up linear velocity while maintaining stability. That has always been the trouble with these aircraft. They're great if you only want to go up or down, but most people want lateral movement as well.

As an aside, I'm not sure why using the Coanada effect is better than just building a ducted fan with internal control surfaces. Putting that big blockage in your airflow just seems like it's going to sap power from your engine.

Re:Maintenance?

[fiannaFailMan]

War equipment needs to be bery quick to fix and and this sounds extremely complex.

Reading TFA will show you that it's actually quite simple, a lot simpler than a helicopter too.

Re:Maintenance?

[DRAGONWEEZEL]

I was thinking the same thing. It's like, Damn, I could have thought of that...

But my curiosity is in energy efficiancy vs. a heli style machine. Yeah, it might be an order of magnitude safer, but if it costs twice as much to run, how much of a help can it be?

I was looking at the video and for secret surveilence I think this wouldn't work. It's WAY too loud. It would be good for commercial arial shots though.

I saw many things in that video alone that made me wonder...

1. Why square (ish?) why not use a circular design? Stering could be done by changing the small stabilizing flaps on the sides, instead of big flaps on the bottom.

2. What happens during freefall? In the event of a motor failure, Aerodynamically speaking (from my weak physics perspective ), it looks as if it will tip upside down.

3. What are the wires from the bottom supplying? Input or power? (my guess is both..)

Re:Maintenance?

[posterlogo]

Slashdot tip of the day : Tags are not comments, they're ment to help people search for topics. Write a comment or leave

Actually, half the tags come across as heavily opinionated comments. Questions are answered "yes" or "no" or often, both. A product that might not work quite right or a company that gets its come-uppens gets tagged "haha".

Ya, these are really going to help anyone search.

Re:Maintenance?

[DRAGONWEEZEL]

I see by some links of a later poster, that some of my questions were answered.

# 3. they have self powered models.
    2. it appears to fall flat, w/ the flaps extending
    1. Square, Circle, Rectangle. Shape matters little. 1.a No one has a model w/ the stabilizer flaps moving (that I saw) 1.a.2 There is a proposal to use flapless by using some kind of plasma fluid. That looks interesting indeed!

Re:Maintenance?

[DRAGONWEEZEL]

OMG my brain is spinning like a UFO!

I have a AirHogs Reflex that I am going to try this effect with! I had the greatest Idea of putting the top of a frappaccino cup. It's a Dome shapped piece of thin plastic that would fit under the rotors. I'll let you know more when I get it together!

Re:Maintenance?

[mhall119]

If your RTWA (Read the Wikipedia Article) you'll learn that the "blockage" isn't at all a blockage, and the air blown down by the fan runs along the side and then straight down, instead of being deflected back up, which means there is no "sapping" of power. This gives you the entire center cavity for payload, instead of making it a hollow cylinder like a ducted fan would require.

Re:Maintenance?

[jandrese]

Yeah, but physics says that if your airflow is being redirected it's not only losing power from changing the direction of the flow, but also from friction between the airflow and your surface.

Re:Maintenance?

[Anonymous Coward]

It's just a matter of blade length.

The flapping motion dumps lift from the forward moving blade to keep the lift equal on the fore and aft moving blades.

If this thing gets big enough to carry a significant amount of weight, or to move linearly at high speeds - it'll have blades that flap around as well.

Re:Maintenance?

[flyonthewall]

This type of shape must have a very low VNE. It seems to me that as soon as you exceed translation you lose all benefit from the Coanda effect as your airflow is no longer going over your curved surfaces. At that point normal wing aerodynamics start to be effective and it seems, to me at least, that those thing would tip over from the drag being induced on the surfaces leading edge.

Then again, I might be wrong, but is interesting speculations.

Re:Maintenance?

[The Raven]

I am not certain it is better. But there are some possible reasons it is better:

It may be stable without any control inputs. Internal-fan lifting bodies tend to precess and flip without corrective control.

It may be resistant to bumping walls. The air flowing over the surface may push it away from obstructions, making it valuable for maneuvering in tight spaces.

I suspect it is less maneuverable, but more stable, than a contained propeller VTOL. This is an advantage in urban situations. But it's pure speculation... I don't know any more than you do.

Re:Maintenance?

[mhall119]

This design might lose some energy to friction, but that can be made insignificantly small by using a smooth surface. The energy you lose from redirecting the airflow depends on the new speed and direction of the airflow. In this design, the speed and direction remain almost completely unchanged due to the Coanda effect, so there is very little energy loss.

Re:Maintenance?

[julesh]

As an aside, I'm not sure why using the Coanada effect is better than just building a ducted fan with internal control surfaces. Putting that big blockage in your airflow just seems like it's going to sap power from your engine.

That's actually the answer to the problem you mention in your previous paragraph. You're now moving air across the surface of your device to generate lift, so all you need to do to generate forward motion is to stop pulling it down so much at the back. By manipulating control surfaces you can change some of your lift to forwards acceleration. And because you don't rely on the mixing of two different air streams for your lift, you don't have problems with turbulent effects when you have substantial forward motion. I think this design is substantially more stable at high speed than the older ones.

Re:Maintenance?

[radtea]

Yeah, but physics says that if your airflow is being redirected it's not only losing power from changing the direction of the flow

Fluids is a tricky subject, and not just grammatically. So long as the force doing the redirecting of the flow is everywhere normal to the direction of the flow there is no power expended in the process of redirection. This is not quite the case in the Coaanda effect, which seems to be mediated by frictional effects, but one of the startling things about it is that the normal forces are much larger than the frictional forces, so you do get substantial redirection with very small losses.

Re:Maintenance?

[Farmer Tim]

The loss of thrust to drag probably isn't significant in a craft this size and weight. It won't scale up, but then I suspect a design like this couldn't be used for people or cargo for safety reasons (I don't think it would autorotate if the engine fails, but I could be wrong).

One advantage with this is that the weight of the vehicle suspended directly below the fan makes it inherently stable; useful if the control system dies, because it will tend to return to neutral and hover in place. By comparison the Avrocar was top-heavy and attempted to balance on it's thrust, resulting in a design that was unstable even when hovering (you can see this in the test footage).

The second advantage of this design is that the engine's drive shaft can be directly coupled to the fan. Compared to a helicopter (which needs a complex transmission to allow vectored thrust) or an unobstructed ducted fan (requiring some kind of belt or rim-drive, and a weight to counterbalance the engine which would have to be mounted off-center to avoid drag), this system is extremely easy to maintain and has fewer failure modes.

A third advantage, particularly applicable to drones, is control simplicity: at a pinch you could get away with as few as two servos for complete control in the X and Z axes by mechanically linking the flaps on opposite sides with simple push-rods. I can't think of a simpler control mechanism for a hovering aircraft, but IANAAE.

Re:Maintenance?

[budgenator]

If you want to know how to get around the rotor stall problem, you have to look to the masters of rotory wing flight, the Russians. The Russian answer is contra-rotating wing, each side has equal lift and the additional benefit is you get to have two Jesus nuts instead of one. The Jesus nut is the nut that holds the rotor shaft on, if the Jesus nut falls off all you can do is say "Oh Jesus"

Re:Maintenance?

[kimvette]

Sure it will. I know that if I want to search /. for discussions about Vista, all I need to search for is "defectivebydesign" or if I want to find articles about Microsoft bugs, I just need to search for "haha"

So, don't try to tell me that the tags are not providing any benefit!

Re:Maintenance?

[Anonymous Coward]

I believe that any problems with maintenance, even in the beginning, will be greatly outweighed by the "helicopter's" performance. The rotor is in a protective cylinder, as well as set back from the sides, so as to allow bumps and minor collisions To the naked eye, the outside of the machine, really, does not look that complex at all. In addition, the responsibility of repairs in surveillance situations and wartime would be placed on incredibly experienced engineers and mechanics with extensive knowledge on the device. Lastly, during wartime, one would assume that the need to resolve any problems encountered would be of the utmost urgency. However, one should keep in mind that the initial role of this "helicopter" would most likely be unmanned surveillance missions, where no lives are at stake.

Re:Maintenance?

[mrcaseyj]

>[the friction] can be made insignificantly small by using a smooth surface.

Actually it turns out that a large portion of aerodynamic drag is caused by the sticky air in contact with the surface of your vehicle. You can think of air as kind of like a thin syrup. It's stickier than it seems. Even an object such as a very thin sheet slicing straight through the air has significant drag, no matter how polished it is. In fact the viscous drag can even be the majority of drag in an aircraft.

Re:Maintenance?

[onescomplement]

To do anything like stability for the Avrocar it would have required several tons worth of compute power to even have a hope of stabilizing the thing when tilted.

Nowadays, gyros and servos are pretty darned cheap and in fact required to fly many model helicopters. Not to mention compute power.

Nevertheless, hovercraft, if you ignore the whole twirly-whirly aspect of this gizmo are generally powered by a lift fan and a direction fan. So you vent the duct a little bit, make the direction fan swivel in 2 dimensions, with a little cooperation from the existing flaps to ensure stability, voila.

Hell with the military ramifications, this would be a great frickin' toy and compared to electric helicopters, pretty foolproof and simple. Put a little netting over the ducted fan and fingers will be spared.

Anyone see a parallel here?

[Anonymous Coward]

This guy in his shed is the same as many of the Linux kernel developers in their basements.
People laughed at them, but then they came up with something that changed the world!

Re:Anyone see a parallel here?

[Anonymous Coward]

I wish him success. Here is a man who didn't troll physics forums with crank theories, he produced results.

Re:Anyone see a parallel here?

[Anonymous Coward]

Do these remind anyone else of the flying drones the police used in Dark Angel?

Re:Anyone see a parallel here?

[linguizic]

Except I don't think his mother owns the shed, and I doubt he's living in it.

Penguin on a treadmill

[electrofreak]

I like the story about penguins on a treadmill more.

Re:Penguin on a treadmill

[electrofreak]

sorry: link

Scaling up?

[Anonymous Coward]

Do the aerodynamics work if this is scaled up in size? I want my flying car already!

Re:Scaling up?

[general scruff]

Depending on what the power/weight ratio is, I bet you could take 3 or 4 of these and put them at the corner of a triangle or a rectangle, and you would have your flying thing... Looking at the simplicity of his contraption, I think it would take less than 6 months of R n D to get it up and running!

Woohoo!

Excellent!

[Vexor]

Now we have our own device to abduct aliens from their homeworlds.

Re:Excellent!

[andphi]

Why would we want to do that? We'd send our technology to the far reaches of known space and get only hicks and bumpkins in return.

Re:Excellent!

[Farmer Tim]

Why would we want to do that?

Revenge probing?

Best link in the article

[Realistic_Dragon]

Video: Penguins on a treadmill - the latest (and most bizarre) way to save the planet.

Now we see Linus' master plan. Apparently he didn't get enough karma for Linux.

Coand effect

[Manhigh]

Aren't pretty much all low-speed aerodynamics based on this? Isn't this pretty similar to the Kutta Condition? (Air tends to leave a sharp edge parallel to that edge).

If air didn't stick to smooth leading edges, aircraft could never get enough L/D to fly subsonic.

Re:Coand effect

[Red Flayer]

No. The Coanda effect is different than regular wing aerodynamics. The Coanda fallacy, the first external link on the coanda effect wikipedia article, explains the differences.

Re:Coand effect

[barakn]

It's interesting that you bring that first link up. The second link, Coanda Effect: Understanding Why Wings Work, is from no less than Jef Raskin, the father of the Mac. It contains a fallacious argument on why the Bernoulli effect can't explain the lift generated by a wing, which he claims he first derived as a child. It contains some child-like assumptions, the most grievous being the assumption that the ratio of the chord lengths (distance over the wing versus under the wing) is the same ratio as the speed of the air over the wing versus under. This implies that two air molecules that separate at the front of the wing, one going over and one going under, will meet at the back edge of the wing, as if joined by some invisible rubber band. In reality the ratio of the speeds is larger than the ratio of the chords, and the top molecule reaches the back long before the bottom one does. This link to a different page on the same website as the first Coanda fallacy link, shows the airflow using smoke pulses and does a great job of describing what is going on.

My one question

[rehtonAesoohC]

Disclaimer: I'm not aeronautical engineer, but...

I'm curious whether the flying saucer would be stable and not spin around. Helicopters have rear rotors so they can counteract the spin forces induced by the main rotor. Other helicopters have two rotor blades on top of each other, one spinning one way, the other spinning the other way.

Without a design that counteracts the torque caused by the only rotor, what is it that will prevent the UFO thing from spinning around like crazy?

Re:My one question

[Vexor]

Well the picture had fins for steering. Helicopters don't too my knowledge. In fact helicopters steer by tilting in the appropriate direction if flight sims taught me anything. Also this "hover-copter" is pushing/sticking air all around it's sides because of the shape so I think the force would equal out because it would be equal on each side. A helicopters is focused directly on one side so it can go that direction. Just my guess.

Re:My one question

[Anonymous Coward]

I'm an aerospace engineering student.

Note the scoops on the sides. They're all directing the airflow clockwise (as seen from top). If your rotor is also spinning clockwise (as seen from top), the airframe will be torqued counterclockwise, and those little scoops will counter the torque.

Just my guess.

Re:My one question

[RegularFry]

Observe the channelling fins around the edge along each side. They aren't quite vertical. My guess is that the angular velocity they impart balances the torque of the rotor.

Re:My one question

[jhfry]

If you look at the sides of this device, you will notice there are ridges that look like they redirect the air in the opposite direction of the rotation of the blades, essentially negating the rotation.

Re:My one question

[brunascle]

maybe that's what the near-vertical flaps on the side of the thing are, to counteract its implication to spin.

Re:My one question

[Radon360]

From what I can tell from the picture, a small amount of the downward thrust is directed in the opposite direction of the rotation, producing the necessary counter torque.

Re:My one question

[Nos.]

My understanding was that a helicopter turned by varying the speed of the tail rotor (assuming a tail rotor model).

Re:My one question

[Rogerborg]

There's a little goblin inside who spins it the other way.

Not funny, not informative, but at least it's not another dupe.

Re:My one question

[Anonymous Coward]

Did you watch the f'ing video?

Re:My one question

[Anonymous Coward]

"In fact helicopters steer by tilting in the appropriate direction if flight sims taught me anything."

Apparently they didn't. Tilting the main rotor is what makes the helo move in one direction or another. Turning the fuselage is accomplished by changing the amount of torque compenstation. On most helos that means changing the speed of the tail rotor. On models with counter-rotating main rotors, the relative velocities of the two rotors are adjusted.

"pushing/sticking air all around it's sides because of the shape so I think the force would equal out because it would be equal on each side. "

"pushing/sticking" (gotta love those technical terms) the air the same amount in all directions means that the craft will maintain a neutral position but does nothing to prevent the torque of the main rotor from making this thing spin like a top. It's that whole "Equal and opposite reactions" thing that you may have heard about.

Re:My one question

[Anonymous Coward]

Maybe you should watch the video to see that it doesn't spin around before making a stupid comment.

Re:My one question

[JesseL]

Conventional helicopters counteract the torque of the main rotor and control their rotation (yaw) by varying the pitch of the tail rotor. The tail rotor is mechanically geared to the main rotor so that both rotors always maintain the same ratio of rotation speed.

There are a few radio-control helicopters that have a separate motor for the tail rotor and vary its speed for control, simply for the sake of mechanical simplicity.

Re:My one question

[BostonPilot]

There are two different mechanisms used to yaw a helicopter, depending on whether we are talking about in forward flight, or in a hover.

In forward flight, the main rotor thrust is tilted which pulls the helicopter to the side. As the helicopter moves to the side, the vertical fin at the rear of the helicopter provides weathercock stability, much like the fins on an arrow. This yaws the helicopter in the pro-turn direction. Some helicopters need a little bit of pro-turn anti-torque pedal, but this is a minor correction to keep the aircraft in trim. Most of the yawing force in forward flight is being provided by the (fixed) vertical stabilizer.

In a HOVER, a conventional helicopter uses tail rotor thrust to yaw the aircraft. As a previous poster pointed out, this is done by changing the angle of attack of the tail rotor, not by changing the speed. As he pointed out, in full size helicopters, the main rotor and the tail rotor are connected by drive shafts and transmissions, meaning their speed is always at a fixed relationship to each other. This is done so that during unpowered flight (autorotation) the main rotor can keep the tail rotor turning, to give the pilot yaw control during the glide and landing.

Also, you are incorrect about how counter-rotating helicopters generate yaw forces. A tandem rotor helicopter like the CH-46 and CH-47 generate yaw forces by tiling the front and rear rotors in opposite directions. To yaw left, the front rotor is tilted to the left, and the rear rotor is tilted to the right. Coaxial and intermeshing helicopters generate yaw forces by changing the relative pitch of the rotors. This causes the rotor turning in one direction to generate an increased torque force, while the rotor turning in the opposite direction generates decreased torque forces. The imbalance causes a yawing force. Note that these systems need to work backwards when in autorotation. I've never flown one of those systems, so I only know what I've read - someone who has flight experience in a Kaman or Kamov might comment?

Back to the particular device in the article, the anti-torque force seems to be generated by a combination of fixed fins around the circumference (note how they are all bent in the anti-torque direction) and the (4?) moving fins which are probably there to provide yaw control to the operator.

Re:My one question

[budgenator]

Normaly the "tail rotor" or more properly called the counter-torque rotor is used to keep the helicopter pointed in the desired direction of travel which has a lower aerodynamic cross section but this is optional because a helicopter can fly forward, backward and sideways. Durring normal flight to change an aircrafts direction of travel changes to pitch, yaw and roll are all made.

UK definately dropped the sauser on this one...

[jhfry]

and spilled the tea!

This is an excellent idea. Almost one of those head slapping "why didn't I think of that?" type ideas.

I could see these replacing many unmanned aerial recon aircraft in urban and other areas where there is potential for the craft to bump into objects. Hell, with a bit of inlet cowling to prevent debris from hitting the propeller, I would suspect this thing could be used in wooded areas like dense jungles where typical surveillance craft can only use infrared.

Definitely a marketable idea! A+ to the US military for recognizing potential and buying it! Of course, our military buys into every crackpot idea, so it's no surprise!

Hmm... now that I think about it... the US military is kinda like Google... spend money everywhere and your bound to spend it in the right place eventually. When the goal is to maintain technical superiority, I guess it's worth the cost, seems to work for google.

Re:UK definately dropped the sauser on this one...

[WhatDoIKnow]

The Chinese are ahead of us in this technology: http://www.bycase.com/Remote-Controlled-RC-Flying- Saucer-WHOLESALE-p-16133.html?gclid=CNugkOK4tosCFR 3qgAodslMIvw

:wq

Re:UK definately dropped the sauser on this one...

[Anonymous Coward]

I have two of these. They were extremely cheeap, $15 Cdn each, and they are fun to fly. One has very little, (ie; no) horizontal directional control, and if you do hit a wall, they like to flip over and crash.

Other than that, they are lots of fun. Oh yeah, and don't fly them outside if there is even a hint of a breeze as they tend to follow the wind.

Re:UK definately dropped the sauser on this one...

[ScrewMaster]

When the goal is to maintain technical superiority, I guess it's worth the cost, seems to work for google.

Which just means that you end up maintaining superiority ... technically.

Hmmm...

[ProteusQ]

It just won't seem real to me until it fires laserbeams from its undercarriage at passing motorists and pedestrians while the words "De-stroy! De-stroy!" are chanted from its external loudspeaker system. If its targets all looked 50's retro, that would help too.

Re:Hmmm...

[Lurker2288]

I think "EX-TER-MIN-ATE! EX-TER-MIN-ATE!" would also be appropriate. Variety being the spice of life, and all.

Re:Hmmm...

[ProteusQ]

Maybe the genocidal aliens could be sensitive to our cultural needs, yelling "Ex-ter-min-ate!" in Britian and its former colonies and "De-stroy!" here in the US. Other linguistic changes would follow mutatis mutandis. It would be nice to know that the human race wasn't overrun and murdered by insensitive clods!

Re:Hmmm...

[CmdrGravy]

The ones in the US could shout "LIB - ER-ATE, LIB - ER-ATE WE WILL FREE YOU - LIB -ER-ATE" like the Martians in Mars attacks "We come in peace" bang - shoot - fizzle - "We are you friends" slaughter - annihalate - kill.

Amazing opportunity...

[cno3]

For a new breed of modern warfare. Simply fill the device with eels...

Re:Amazing opportunity...

[LouisZepher]

I will not buy this record, it is scratched...

Re:Amazing opportunity...

[Rob the Bold]

Uh, no, no, no. This is a tobacconist's.

Re:Amazing opportunity...

[Raffaello]

Please fondle my buttocks

Re:Amazing opportunity...

[Raffaello]

oops, should be "Please fondle my bum."

Re:Amazing opportunity...

[Anonymous Coward]

My nipples explode with delight!

Re:Amazing opportunity...

[TeknoHog]

My plane is full of snakes.

seems inefficient?

[llZENll]

How is forcing the airflow over the body of the aircraft itself an improvment over an open airpath directly through the craft (a hole)?

Re:seems inefficient?

[Capt James McCarthy]

You can place cargo, cameras, bombs, etc.. within the 'hold.'

Re:seems inefficient?

[Rogerborg]

It's far more efficient than a helicopter. It's getting lift both from the airflow over the rotating blades, and from the flow of the downwash over the body. In a traditional helicopter, most of that downwash is simply wasted.

Re:seems inefficient?

[jhfry]

Hovercraft's that use the technique you describe would be required to move a lot more air, and do not do so well at higher altitudes where the air is thinner. This is due to their lift being generated entirely by creating a low pressure zone above the craft by moving huge quantities of air from one side of the craft to the other.

This craft moves a smaller amount of air across it's surface, like the wing of an airplane, the way the air flows across it's surface creates the low pressure zone necessary to create lift.

The method you discuss, works well in situations where the rotors are very large in relation to the body of the craft, while this method works even when the rotors are much smaller in relation.

I am sure someone with a little more understanding of the physics involved could improve upon what I just said, but I'm pretty sure this is the way it works.

Re:seems inefficient?

[Anonymous Coward]

because this would require a big hole through the fuselage of your aircraft. This would displace necessary components such as the engine, and any potential payloads (or if built big enough, passengers). For a craft that would probably be best served taking up as little volume of space as possible, sending the air through the center sounds like a waste of space and a detriment to the overall structural integrity. Although I do admit these are just guesses and I'm not an aeronautical engineer.

Re:seems inefficient?

[LWATCDR]

All "lift" is generated by down wash. All that low pressure on top of the wind and high pressure on the bottom is just a convent fiction to make the math easy.
As to how efficient this is. I don't know it may have a lot of advantages at low Reynolds number but totally fall apart at higher ones.
In other words it may be the bee's knees for a small drone but fail totally for a replacement for a Blackhawk.

Re:seems inefficient?

[Ceriel Nosforit]

Might be that the Coanda effect direct the air-stream directly downwards, but yes, the design seems rather inefficient. It appears that the only reason it is stable is because the plastic skirt-thing simply weights enough to keep the whole thing aligned.

What makes it better, or more news-worthy, than for example this design;
http://www.globalsecurity.org/intell/systems/image s/cypher-pic2.jpg ...is beyond me.

Could be the whole point of the article is the humane angle; that an old guy built it in his shed. However, taking into account that the guy has been doing this professionally for what appears to be quite a while, it doesn't seem special at all.

Re:seems inefficient?

[Anonymous Coward]

Did you NOT read the article on the Coanda effect?

Re:seems inefficient?

[mhall119]

One word: payload.

Consider the 2 designs, and think about where you would place the payload, and how much of it you can have.

In your link, the craft needs the central area clear of obstacles to allow airflow, leaving only the perimeter available for payload. In the article's craft, the air is directed around the perimeter of the craft, leaving the central area available for payload.

Re:seems inefficient?

[Moofie]

TANSTAAFL, especially in aerodynamics.

I'd need to play with one to see for sure, but I think the key feature here is the anti-torque stator vanes on the shell. Otherwise, my intuition tells me that a direct-lift system would be more "efficient" (in terms of pounds of lift per watt of electrical power).

Or I could be mistaken. Low-speed aerodynamics is a very tricky business.

Re:seems inefficient?

[MobyDisk]

I don't know aerodynamics very well either. But I think you are correct. When I first watched the video, my question was "why doesn't it rotate from all the torque of that motor on top?" The stator vanes (never heard that term before, but I assume that means the little things on the outside shell around it) are probably the issue. Because on a helicoptor, you need a second propellor or a tail propellor to fix that problem.

Re:seems inefficient?

[foniksonik]

This way he can patent it?

IANAAE

Actually I suspect that the whole Coanda effect thing is the main difference, well that and the fact that it's inverted bowl shape helps it stay aloft on the cushion of air it has generated... like a parachute with it's own updraft generator. The bowl shape looks to actually curve up under itself... so the air that is following the curve is being redirected up under it - not simply down, so in the end you've reduced the air density above the device and increased it below the device, pretty nifty.

Re:seems inefficient?

[OwnedByTwoCats]

You can make a single-rotor helicoptor. It just can't torque the rotor blade itself. If you fed compressed air into the rotor, and it had a backward-pointing nozzle at the tip of each blade that spun the rotor, then you could fly with only one rotor.

Prolly wouldn't be very efficient, which is why it isn't used much today. Maybe as a childrens' toy, with a balloon for the source of compressed air?

Re:seems inefficient?

[Rogerborg]

How do fixed wing aircraft stay in the air, if lift from low pressure on the top of aerofoils is 'fictional'?

Re:seems inefficient?

[Moofie]

One of my favorite toys is a long garden sprayer (the three-foot extendable rod kind). If you hold the hose part, and turn on the water, you can fly the head of the sprayer around and play Lunar Lander (if you have the spigot close to hand).

Anyhow. That's the kind of dork I am.

Re:seems inefficient?

[LWATCDR]

How do they fly inverted if it isn't? How does that wind up toy plane with balsa planks for wings fly if it isn't fiction? How would any aircraft with a symmetrical airfoil like the F-16, or the Pitts Special fly? What about a hang glider?

All plays fly by deflecting air down. A curved surface deflects a flow of fluid the old blowing out a candle behind the light bulb trick is a great example. BTW gases and liquids are both fluids.

If the old simplification that the air over the top of a classic airfoil generates lift because it has to travel a longer distance than the air over the top where true then an airfoil where the top was a series of bumps and dips would make a lot of lift, It doesn't.

There is more pressure under the wing because the wing is pushing the air down. It is actually thrust.

How ever the simple version of how an airfoil works does work just fine until you try to make a very efficient aircraft. Sort of like how Newtonian physics works just fine until you get in the extremes.

The other thing that most people don't know is that scale means a lot. An airfoil that works great on a plane B-17 will not work on a well at all on a hand thrown glider. The size of the wing and the speed really effect the way airfoils work.
For most people this is all a lot more than they need to know.

Re:seems inefficient?

[Rogerborg]

What's your thoughts on this hovercopter then? Is the lift generated over its body actually real, or it the body just a way of mounting fins that divert the flow and counteract the rotor's torque?

Re:seems inefficient?

[LWATCDR]

Very short answer is who knows? Way too little information in the article.
Short answer is maybe. By spreading the airflow over the body you could get a some extra thrust at low speeds and hovering is a very low speed. The spread out air flow could accelerate the surrounding air and give a boost in thrust. The most efficient way to generate thrust is to accelerated as much air as possible to the lowest speed possible. That is why a prop is more efficient at slow speed, a turbofan is more efficient at medium speeds and a turbojet is most efficient at very high speeds.
What I doubt is that it can scale up. Nothing in aerodynamics is free. By spreading the airflow over the body you are increasing the drag on the airflow and slowing it down. With a small vehicle you may get more benefit for the extra air that gets dragged along than you loose form the drag of the airflow on the body. It could be great for a small drone but I just don't think it will work at human scale.
Remember the old wives tale about it being aerodynamically impossible for a bee to fly? Well a bee the size of bee can fly a bee the size of a humming bird can not. Same principles may apply here but without seeing numbers and details I am just guessing. Besides when anybody claims a great breakthrough in flying machines I go ultra pessimistic. Too many claims that have totally failed. Show me the data or better yet, fly it at Oshkosh.

Look at those curved fins on the sides.

[porkchop_d_clown]

I bet they direct the thrust to counteract the torque of the motor.

From the video, it appears

[GungaDan]

that the military is only interested in surveillance of VERY LOUD PEOPLE. That thing shrieks...

Re:From the video, it appears

[X0563511]

This was built in a shed, by a civillian.

If the military threw money and talent at it, i'm sure it could be made very quiet.

Re:From the video, it appears

[LiquidCoooled]

To get the effect you have to force air over the surfaces.
To counteract the torque, you have to force air over the flaps and bafflers.
Anytime the air is turbulent it will make noise.

This bitch screams like a banshee because the motor is working overtime because aerodynamic efficiency is very low.

Good luck in making it quiet.

Re:From the video, it appears

[X0563511]

There is the issue: noisy motor.

That is defiantly something that can be quieted. Also, I'm sure using special low-friction surfaces (and maybe channels instead of just going around) can easily increase efficiency. How far, I'm not sure... I'm NOT an aerospace engineer.

RTFA

[Anonymous Coward]

``Unlike a helicopter, though, this is aerodynamically neutral and you can bump into walls and not smash the rotor,'' said the inventor.

Re:UK definately dropped the saucer on this one...

[jhfry]

Before someone comments on the misspelling of saucer, I noticed it too late.

Before someone comments on the cheesy subject line... I know, it's bad.

Save your comments for something meaningful, like calling me a dolt or something like that.

What to call it?

[Tickenest]

I think hovercopter beats helicraft, but that's just me.

Re:What to call it?

[Fear the Clam]

Tiger Claw beats hovercopter.

Re:What to call it?

[owlstead]

I think the Hatton Hoover sounds cool. Although it will probably get changed to "keep-your-hat-on, hoover!" when this thing gets to be deployed for surveilance :)

Re:What to call it?

[GlasWolf]

Holicrapter.

Too late. The US Army has already picked...

[Anonymous Coward]

this.

Why is this a great idea?

[The Living Fractal]

Someone tell me how this is better than the alternatives?

This thing has to carry heavy batteries or fuel, limiting its range. And it's ungodly loud. A small dirigible is silent and I imagine you can make one pretty small given how lightweight today's surveillance tech is.

Seems like the only thing this might have over a blimp is speed. But if it's speed you want... what's wrong with a winged drone that can do tight circles over an area?

Is it the VTOL aspect?

I just want to know what the US mility finds so great about this, and the article doesn't really say.

TLF

Re:Why is this a great idea?

[fiannaFailMan]

This thing has to carry heavy batteries or fuel, limiting its range. And it's ungodly loud. A small dirigible is silent and I imagine you can make one pretty small given how lightweight today's surveillance tech is.

Sounds like a great argument against helicopters too.

Re:Why is this a great idea?

[Anonymous Coward]

Yes, it's the VTOL aspect. Small blimps only work in zero-wind situations. Blimps also present a large, slow, very vulnerable target. Winged craft, even with the tightest available turning radius, cannot perform usably in an urban canyon, such as, say Downtown Baghdad. Small winged craft cannot provide a stable platform for a laser designation device in urban terrain. While these type of aircraft are noisy, you show your obvious lack of military tactical training: these noisy devices can be used to mask noises and redirect an enemy's attention away from the real incoming attack.

Re:Why is this a great idea?

[Rob the Bold]

A small dirigible is silent and I imagine you can make one pretty small given how lightweight today's surveillance tech is.

As cool as that would be, the lighter you get the more easily you can be carried away by a gust of wind. And the lift of a LTA craft varies with the cube of linear dimension. Otherwise, I'd welcome our zeppelin-riding overlords.

Re:Why is this a great idea?

[e2d2]

Question: how do you fly a blimp in wind?
Answer: you don't.

Blimps are slow and fragile and take up a lot of space just to carry a small payload.

What they need is something that is durable that can enter a structure and look around, this thing would do nicely because it's blades are enclosed and it's relatively simple mechanics compared to a helicopter (although this is changing on small R/C helicopters with counter rotating blades and built in IMUs for stability).

Lots of RC people working on the same thing

[serbanp]

See here. It's significantly harder than it seems, kudos to this guy for being able to "fly" it in a stable manner. The thing with the patent is shameful though.

Re:Lots of RC people working on the same thing

[LiquidCoooled]

Theres a guy posting videos of his attempts, and I just realised what we are watching:

Airborne roombas!

Tom Swift Jr.

[tb3]

I guess I'm the only one who was reminded of Tom Swift and his Diving Seacopter. (Although this one doesn't seem the be submersible.)

Re:Tom Swift Jr.

[VAXcat]

Almost any vehicle is submersible...once.

Re:Tom Swift Jr.

[einnar2000]

It is submersible.....

once.

Re:Tom Swift Jr.

[Nefarious Wheel]

No way. It has to be his Triphibian Atomicar.

Re:Why is this a great idea? - It's a ROFLCOPTER!

[bitrot42]

Duh!

More of a flying hovercraft, not a helicopter

[Radon360]

If you look at the main "lift generating mechanism," it is essentially a fan/turbine, not a wing. As such, it generates its lift by forcing air downwards, developing thrust. A helicopter's main rotors are shaped liked wings (airfoil) on a fixed-wing aircraft. As such, the wing develops lift by forcing the majority of the air over the top of it to create an area of low pressure over the top of it as it rotates.

While its flight my appear to behave like a helicopter, it is not working on the same principles of flight that a helicopter uses.

Re:More of a flying hovercraft, not a helicopter

[Anonymous Coward]

Finally, a common sense post. Mod parent up.

Re:More of a flying hovercraft, not a helicopter

[kaizokuace]

actually the only difference between a simple propeller and a helicopter rotor is that the rotor on the chopper has variable angle adjustment to increase lift. basically with a rotor or propeller you can change 3 things. The angle that it cuts into the air and the overall length of the blade and the speed at which it is spinning. Changing these basically affects how much air the thing can plow through. The thing about a hovercraft is that it doesn't have a means to counter the torque from the main prop. But its also usually not very far above ground or water, and has a skirt to direct the air down. I think the body of this hoverthingie kind of acts like the skirt of a regular hovercraft but kinda flipped inside out.

Re:More of a flying hovercraft, not a helicopter

[Anonymous Coward]

Close, but not quite right. Im being picky here, but IAAAE (i am an aerospace engineer) and it bugs me to see all the incorrect definitions of lift.

The main lift mechanism for this vehicle is the Coanda effect. The acceleration of the fluid as it curves around the body of the "ufo" generates the majority of the lift. The fluid curves because it is a viscous fluid and experiences boundary layer attachment, ie there is friction between the fluid and the surface which keeps it "attached" to the convex shape. I assure you that the thrust generated by his tiny propeller is not nearly enough to lift the vehicle vertically by itself.

"As such, the wing develops lift by forcing the majority of the air over the top of it to create an area of low pressure over the top of it as it rotates."

There is no majority or minority of flow over an airfoil. In fact, boundary conditions for the freestream are generally positive and negative infinity. If lift was only generated by more flow going over the top, airplanes would have a really hard time flying inverted!

Lift is indeed generated by the integration of an asymmetric pressure distribution, but the interesting thing is what causes the asymmetric pressure distribution. Simplified a bit, lift is a reactionary force on the wing, generated by the downward change in momentum imparted to the fluid due to the airfoil's shape.

Or you can explain lift with circulation theory, which is a mathematical model that makes no practical sense to anyone :)

Re:More of a flying hovercraft, not a helicopter

[julesh]

If I understand the implication correctly, the fan is not used to provide thrust, but to create a layer of moving air across the surface of the device, which in turn causes thet device's body to behave as a wing. According to the wikipedia article, this has been exploited before by aircraft that mount a jet engine above their wings, but I guess this is the first time it's been exploited with an electric fan...

Re:More of a flying hovercraft, not a helicopter

[drinkypoo]

If I read the articles and various supporting materials correctly, the fan is being used to provide thrust, and the Coanda Effect (which depends on thrust) is responsible for making that thrust useful by having it flow down the sides of the craft.

Re:More of a flying hovercraft, not a helicopter

[Radon360]

Desite your reply as an AC, I have to give you credit for correcting me on this one. You pointed out something that I did miss. I did recognize that the Coanda effect was redirecting the airflow downward around the edges (I have air knives here at work that do this), but missed that the air movement over the surface would also generate a lifting force as well.

Re:More of a flying hovercraft, not a helicopter

[Anonymous Coward]

My apologies for the AC post, but my employment has made me a big "tinfoil hat" about tying posts to names and screen names.

And you had the right idea. Your point about the UFO vehicle being innately different from a helicopter is valid and correct. I was just cleaning up the physics.

Re:More of a flying hovercraft, not a helicopter

[blank axolotl]

No.
One way of looking at an airfoil is that there is a pressure difference between the top and bottom sides, causing an upwards force. However, this interpretation is totally equivalent to the one that the airfoil is deflecting the flow of air downwards, and so the helicopter moves up by conservation of momentum. Both interpretations are true and equivalent, just different ways of looking at the same thing. Therefore, this device works in the same way as a helicopter.

PS. I think it would be much easier to use the momentum explanation on kids in elementary school (I got the bernouilli one). Neither explanation, given at an elementary level, says why the airfoil has this effect (either causing air to move faster on top, or causing a downwards deflection - and no, the path length difference is an incorrect explanation), so they are just as incomplete, and the momentum one would be an intro to conservation of momentum.

Re:More of a flying hovercraft, not a helicopter

[Khashishi]

Both this thing and a helicopter produce lift by forcing air downward. The pressure thing is nonsense.

Re:More of a flying hovercraft, not a helicopter

[Anonymous Coward]

Get a room, funboys.

ok, no fuss about the sauser

[Anonymous Coward]

But WTF is this: "spend money everywhere and your bound to spend it in the right place eventually" You guys should learn using your language.

Re:ok, no fuss about the sauser

[jhfry]

LOL... you're right, your was not correct, I humbly ask your forgiveness.

Re:ok, no fuss about the sauser

[Anonymous Coward]

Not to mention "definately" (in the subject line).

Sturdy vs surveilance helicopters, perhaps

[EmbeddedJanitor]

Considering the context, they probably mean small surveilance helicopters. The small surveilance choppers could likely be taken down with a shotgun.

Re:Sturdy vs surveilance helicopters, perhaps

[Garridan]

Shotgun? Think simpler. The thing relies on the Coanda Effect. Toss a large, wet wad of toilet paper at the thing. Land it on the top, and the thing should spin out of control, if not fall like a rock.

Re:Sturdy vs surveilance helicopters, perhaps

[djdavetrouble]

So what you are saying is that we need to build a new super shotgun that shoots wet wads of toilet paper ? ;)

Re:Sturdy vs surveilance helicopters, perhaps

[Garridan]

Excellent idea! And it should be fully-automatic. I'd bet those things are gonna be a trick to hit.

Re:Sturdy vs surveilance helicopters, perhaps

[Anonymous Coward]

I'm sure some high school kids are working on a solution as we speak.

Re:Sturdy vs surveilance helicopters, perhaps

[MrNiceguy_KS]

File that patent! I'd love a full-auto soggy toilet paper launcher. You'd make a killing selling them to teenagers for Halloween.

The human issue is interesting...

[Anthony Boyd]

...I think the more interesting aspect here is that people in the UK have shopped their inventions to the USA, which bought them, and will likely use them ON the UK. In other words, the UK is perhaps selling technology that will be used against them. Of course that's an exaggeration to some degree, as the USA & UK are pretty chummy. But still, isn't it odd that surveillance technology is being giving to other countries? I'm pretty sure we haven't loaned out any of our stealth planes, or even made the specs available. Are there gaps in my understanding that others could fill?

Re:The human issue is interesting...

[jo7hs2]

Wait... That may be so, but it sure seems like your own government does a wonderful job of monitoring you quite on its own. And the UK has stealth planes?

Re:The human issue is interesting...

[Anonymous Coward]

But still, isn't it odd that surveillance technology is being giving to other countries?
 
Especially as the future's apparently so grim:
 
  http://www.guardian.co.uk/science/story/0,,2053020 ,00.html
 
perhaps they're gonna wait till they make one that can shout at people ;-)

Re:The human issue is interesting...

[egamma]

Actually, the UK and US spy on each other AT THEIR OWN REQUEST, because this neatly gets around laws regarding wiretaps, etc. "I'll spy on your citizens if you'll spy on mine, and we'll swap data."

Re:The human issue is interesting...

[ScrewMaster]

And the UK has stealth planes?

Well, if they are stealth planes ... how would we know?

Tag: eelsonahelicopter

[Nimey]

Monty Python: "My hovercraft... is full of eels."

MPlayer users - email the newspaper

[Anonymous Coward]

Dear newspaper people,

Please use open standards (such as theora) for your streamable video. This hopefully prevents my media player from giving me sarcastic back-chat.

"Everything done. Thank you for downloading a media file containing proprietary and patented technology."

Regards,

AC

Warp Drive

[Doc Ruby]

So the Pentagon has the money to fund UFO research, but Bush says they don't have the money to fund the Iraq troops past April 15, 2007.

Which programme is more deluded?

DIY rc coanda effect saucer (with plans)

[HansWurst]

http://jlnlabs.imars.com/gfsuav/index.htm
Besides, there's a company claiming to have "invented" this type of craft years ago (hp says 2002):
http://www.gfsprojects.co.uk/
so is the business model the following?

1. patent stuff others invented before (and maybe forgot to patent it)
2. profit
3. ???

(please honor my contribution to a new version of the underpant gnomes joke ;-)

Re:DIY rc coanda effect saucer (with plans)

[Anonymous Coward]

What's really amazing is that the company you mentioned that already invented this (gfsprojects) was founded by someone *with the same name* as the person who invented that which is mentioned in the article. What are the odds? Staggering! Staggering I say!

You know you've played too much Half-Life

[thewils]

When the first reaction you have to the video is to reach for your shotgun and take out that manhack.

Small UAV

[flyingfsck]

This is a small UAV, not a full blown helicopter people!

It could be nice for exploring the inside of buildings, since it can bump into the walls and ceiling without being damaged.

Re:Small UAV

[hack slash]

You've just jogged my memory with the bit about exploring inside buildings, there's a very similar device used in the film Runaway (1984), at the beginning a domestic robot goes crazy and kills a family, a baby is still alive inside so the police send in a video surveilance unit which hovers about 5 foot off the ground and looks round the house for the baby, until it's shot by the rogue robot.

Keep it small in size

[Radon360]

I think its potential applications are better suited to where you need a small, remote-controlled flying/hovering device, as compared to some huge personnel-carrying machine.

Let's say that you need to do non-secretive reconnaisance in a confined area, such as urban city streets. Flying something like this that's a couple of feet across, equipped with cameras might be the solution. You could accidentally bump it into things and not have to worry about it crashing (as opposed to a remote-controlled helicopter). Surreptition is not needed if you are using it to survey an incident involving haz-mat, fire, or some other industrial mishap.

This might not exactly be best suited as battlefield technology, but perhaps fire/rescue and law enforcement use.

Re:Keep it small in size

[shawb]

Also, in many military and other surveillance tasks, letting people know that they are being watched can be more effective than secret surveillance. It can prevent undesirable activity rather than simply monitor it. Similar to the ubiquitous tinted glass globes in the ceiling of many retail outlets. Often times, these aren't even hiding a camera, just making would be thieves think there is a camera there without actually spending money on the camera or the people to watch the feed.

I think I know what you are all trying to say...

[darkcatalyst]

I think we have to build a space helicopter.

Auto-Rotation

[Paulrothrock]

The rotor may be protected, but how will this thing operate in the event of a power failure? Helicopters can auto-rotate, effectively gliding back to the ground. This thing wouldn't be able to do that, so if you're going to use it for manned craft you're going to need to find some way of bringing it down safely in the event of engine failure.

Re:Auto-Rotation

[Moofie]

"but how will this thing operate in the event of a power failure?"

Very much like a rock.

"so if you're going to use it for manned craft"

Probably not. I'll bet you a shiny nickel that this idea won't scale well, and it's certainly not going to work well at speed.

"bringing it down safely in the event of engine failure."

Airframe parachute.

Re:Auto-Rotation

[Anonymous Coward]

Did you like, read the article at all? This isn't for poeple. It's for small cameras. They want to use it for recon. Stick a little camera in it and fly it around in urban areas where it might smack into walls. The current model aircraft they use for recon cameras can't maneuver well between buildings, and can't hover to watch a spot among buildings for a long time.

Re:Auto-Rotation

[Anonymous Coward]

[...] how will this thing operate in the event of a power failure?

TFA says the Military-Industrial Complex is interested in this as an Unmanned Aerial Vehicle (UAV) platform, maybe.

Don't worry; I'm not mad or anything. I read to both of my own children while they were growing up, too.

Re:Auto-Rotation

[jo7hs2]

Talk to Cirrus. They already make aircraft with ballistic airframe parachutes that can be deployed in the event of an accident, and they've been tested and work. Assuming you could work out clearing the propellor/rotor, adapting such a system would not be difficult.

Best Defense

[Anonymous Coward]

Isn't this the toy that Dudley Moore modifed into a gyroscope cooling system?

Balance

[Radon360]

Putting that big blockage in your airflow just seems like it's going to sap power from your engine.

Agreed, however I think the possible advantage is that you can hang something directly in the center underneath, thus maintaining the center of gravity inline with the fan's center point, rather than trying to balance the payload out when placing it outside the diameter of the fan. That's a big plus. The Coanda effect just allows for them to shed the weight of the ducting by not having to worry about totally enclosing the air flow.

Karma whoring

[Caffeinate]

Maybe they meant "stable"?
You mean like Microsoft software? (Zing!)

Frisbee

[BigFoot48]

This is right up their with the Navy funding research a few years ago into using Frisbees as platforms for flares shot from ships. Wonder how that turned out?

Re:Frisbee

[mh1997]

It looks like it turned into this http://www.defensetech.org/archives/002723.html

Ducted fans

[CustomDesigned]

Multiple internal ducted fans are mechanically simple - but to maintain stable flight/hover requires constant adjustment via computer control. An example would be the Moller SkyCar (and he still hasn't got the computer control working right). This hovercopter has stable flight (at least up/hover/down, not sure about lateral) without complex computer control.

There were also devices with a single internal ducted fan featured on slashdot a while back. These are simple to control, but only if the center of gravity is close to the fan. The payload has to be small compared to the fan. The hovercopter can hold a large payload beneath the dome.

"Wright Brothers"

[mattr]

Interesting how they mentioned this is like the Wright Brothers in terms of being very early in its development.

It sounds like it could work underwater maybe.

It looks like it is made for silicon wafer size engineering, microdrones.

I wonder about the linear speed and turning too. Would it be bad to put wings on it? Is that just a propellor and not a turbine like in the Avrocar? Would a turbine be better, and would tilting it naturally turn the machine's direction through gyroscopic precession?

If you put a rocket on one side, would it stay stable?

Could some kind of electrostatics (perhaps wires suspended above the disk parallel to it) help increase air flow by physically drawing it past the surface? Thinking of the "lifter" models.

If it was rising through a charged fluid you might think it could be leveraged. Usable in high atmosphere?

Is its rate of rise limited by the weight of the cowling it needs as a surface?

Does it use rare earth magnets like in engines inside electric car wheels?

Would a spiral ramp-shaped body like Da Vinci's early helicopter design actually work with a fan on top?

Would another fan help in maintaining stability and speed direction changes, like with helicopters tail blades?

a new form of UAV

[Anonymous Coward]

After playing both GRAW games, i see this article and notice a striking resemblance between this and the UAV cypher used in GRAW.

Being laughed at is not a guarantee of success

[Chemisor]

They laughed at the Wright brothers. They laughed at Torvalds. But they also laughed at Bozo the clown.

Re:Being laughed at is not a guarantee of success

[jd]

You weren't aware that Bozo the Clown was a leading member of the Illuminati, had developed cold fusion, and the real reason so many clowns could get out of the clown car had much to do with his experiments on combining rabbit DNA with human cloning...

Re:Being laughed at is not a guarantee of success

[jcr]

Bozo was probably the most successful clown of all time.

-jcr

I'll believe it when

[Flying pig]

it's in something more respectable than the Daily Mail. For the uninitiated US-ers, the Daily Mail is the UK equivalent of those US magazines with articles like 'aliens abducted my sister'. It pretends to be a newspaper but it is woefully, embarrassingly bad and its articles, to put it extremely politely, would mostly not survive the NYT fact-checking process. Assume, therefore, that this story is over-hyped. The US military has a habit of acquiring any potential military application "just in case" it comes good. Unless there is a huge pork barrel project available, that may well be where it stops. No-one else can legally acquire the technology and they can add it on to the annual list of exciting R&D projects to show everybody is earning their pay.

The only thing in the inventor's favour is that the British MOD has a track record of failing to recognise useful inventions (such as RSA encryption, which it had long before R,S and A and ignored) while spending a fortune on torpedoes that don't work, nuclear submarines with no role, tanks with undersized engines, and rifles that don't shoot properly. For long haired left leaning peaceniks like myself half the charm of the MOD is its ability to reduce the risk that we will get involved in a major war by making sure our armed forces are ill equipped to fight one. (that was sarcasm btw). However, my own view is that they regard flying surveillance vehicles as unnecessary. The plan is to cover the entire planet in talking CCTV cameras, which will probably catch speeding motorists as well.

Prior Art

[Anonymous Coward]

from the old Cox model aircraft company:
http://www.geocities.com/buckrogers_nz/miscvintage .html?20079
or
http://cgi.ebay.com/COX-flying-saucer-Vintage-COX- glow-powerd_W0QQitemZ220100425113QQihZ012QQcategor yZ19164QQrdZ1QQcmdZViewItem
or another, apparently, similar idea:
http://www.freepatentsonline.com/4065873.html
also, one you can buy NOW
http://www.bycase.com/Remote-Controlled-RC-Flying- Saucer-WHOLESALE-p-16133.html?gclid=COmWvK-ytosCFQ tzYAodYhNQzQ

these took about 3 minutes to find.... but are they REALLY prior art? I don't know...
ask
an^H^H aeronautical^H^H^H^H^H^H^H^H^H^H^H^H engineer^H^H^H^H^H^H^H^H^H
a Lawyer

Watch the video on the company's site

[Scrameustache]

video goodness

They talk about scaling up to fit a pilot near the end.

Under emergency situations

[AP2k]

Would it operate on hot air?

tip-driven propellor

[MobyDisk]

This design looks like it might be compatible with a tip-driven propellor. I don't think a traditional helicopter could work with one.

Re:tip-driven propellor

[joto]

Even more likely would be that they used a combustion engine. Most traditional helicopters and hoovercrafts, as well as almost any other kind of flying device, or in fact almost any kind of device capable of moving itself uses them. Electric motors are for prototypes and fixed devices.

Re:tip-driven propellor

[aXis100]

Agreed. Whilst batteries are getting better, the pure horsepower available from a small internal combustion engine (eg methanol) is mind blowing.

My cheap electric planes produce under 100W (10 amp @ 9.6V), signifcantly more expensive versions could do 300W on lithium batteries and brushless motors. Either way, run time is 5 minutes at full power and charging is 10 - 15 mins with an expensive fast charger.

A similar (small) size/weight gas motor could produce 2 - 3 times as much power as the expensive electric option, run for 10 mins, and refuel in 1 minute.

No pitch control on the blades?

[vinn01]

The lack of pitch control says to me that this devices is not meant to go very fast. Probably it is only meant to go up and down, and maybe crab a little sideways.

It think that it will be a great aerial photo platform, as it seems to be designed, but I don't see this scaling into anything larger very easily.

Roads?

[ThanatosMinor]

Before starting it up he should put on some silvery shades and say:
"Roads? Where we're going, we don't need roads."

Who was first? (with video)

[Chr0nik]

http://jlnlabs.imars.com/gfsuav/index.htm Hmmm wonder where that guy got it?

Re:Who was first? (with video)

[nireus]

If you had checked at the end of the page and http://jlnlabs.imars.com/gfsuav/gfsuav.htm you would had seen that the guy is giving credit to Hatton and gives a brief history of machines based on the same physics.

Loss of control on a windy day?

[vinn01]

The Coanda Effect will work great when the airflow is all downward, over the shell. I'm guessing the this craft will not perform very well in high crosswinds. Or even low crosswinds.

Did the military forget they tried this already?

[CXI]

Linked from the Wikipedia article in the summary is the Avrocar: http://en.wikipedia.org/wiki/Avrocar_(aircraft)

That's a full scale model of the very same technology! I imagine in this day and age of computer control it will be more successful, especially as a UAV, but how can this guy get a patent on technology from 1958 and claim it as new?

Looks like the the Drone in Ghost Recon

[rjschwarz]

No further comment

Re:Looks like the the Drone in Ghost Recon

[spiritgreywolf]

I was thinking that very same thing! However if memory serves me correctly, I think the drone in GRAW2 is a ducted fan - where the prop is inside the center cavity and the avionics, etc., would surround the housing.

Plans for building your own

[wrmrxxx]

There are plans to build your own version of this aircraft here, along with quite a few videos of it in flight. I'm amazed by how stable and under control it looks in the video of it flying outdoors in a wind.

Better structure for lift and control

[Ungrounded Lightning]

... the "blockage" isn't at all a blockage, ... there is no "sapping" of power. This gives you the entire center cavity for payload, instead of making it a hollow cylinder like a ducted fan would require.

It also causes the lift (and thrust) to appear distributed over the surface of the fuselage (except for the very center), where it can be easily transferred to support the payload.

With a helicopter lift appears on the rotor. It must first be focussed on the rotor shaft, then passed through a bearing, and finally distributed to the airframe via a skeleton that is hung from the bearing. Here there is a local tug-of-war between the rotor and the center of the fuselage, then the lift appears in a ring around it.

Same idea as the "flying wing". Or Bucky Fuller's "all the strength is distributed through the skin" geodesic designs, with their fantastic strength-to-weight ratios.

Also:
  - The system is more stable with the lift appearing in the outer regions rather than at the center.
  - With a broad lifting surface (like an airplane wing) more ordinary control surfaces can manage the craft's flight - or you can modulate the lift in patches by valving in air leaks to selectively break the airstream attachment.
  - In a helicopter much of the control is done by dynamically adjusting the pitch of the blades using a complicated control structure and shafts in bearings that constantly dither once per rotor rotation - then the forces must be transferred by applying bending stress to the rotor shaft! With the coanda saucer the blades are a solid structure that only creates an airflow, while the control structures only move when the control parameters change.
  - Unlike a helicopter, lift can be adjusted to trim out major offsets of the load's center of gravity.

Re:Best link in the article OMG!

[badc0ffee]

OMG the penguins are the cause of global warming!

FTFA:

They will record how much energy the birds are using in order to feed themselves. If the data shows they are making longer trips further into the oceans to find fish, it may prove waters are warming up and climate change is taking place.

The penquins are warming the water, causing them to go further to find cold water fish, which warms the water even more.

We are all doomed due to penquins.

VTOL UAVs

[Anonymous Coward]

I'm surprised no one has yet mentioned the similarity this machine has to the Sikorsky Cypher.

I have doubts about how large this can be scaled. The primary reason we haven't seen large ducted or ringed rotors on a helicopter is mostly due to the increase in weight, along with some other non-trivial issues of needing to adjust blades indivudally at points in their rotation to maintain control. Ducted fans can work on a smaller scale, but you tend to need more than one of them as seen in the Moller Skycars and a few experimental tilt-duct aircraft. (Check out the nifty VSTOL Wheel for a good overview of other VSTOL concepts.)

It's not a bad idea for a UAV though, seeing as the U.S. military seems interested in developing both conventional and more experimental types of VTOL UAVs.

Make your own

[GrubInCan]

Courtesy of MAKE magazine.

All the examples shown in the video ...

[ScrewMaster]

had tethers, presumably for power since the controls seemed to be RF. I'd be more impressed if the things were flying under their own power carrying a payload.

Heh, Get too close to a wall

[iminplaya]

and that same Coanda Effect might suck you right into it. Stand close a fast moving train to feel the same effect...but not too close...unless, of course, your buddy has a video camera handy to film the ensuing mayhem.

Re:Heh, Get too close to a wall

[Elminst]

Except Mythbusters proved that theory wrong.

You won't get sucked in by the train. However, you will get knocked over by the pressure of the air being pushed in front of it.

Only 260 shopping days left

[iminplaya]

I want one.

It worked for Edison

[camperdave]

1. patent stuff others invented before (and maybe forgot to patent it)
2. profit
3. ???

Well, it worked for Edison.

Re:Did the military forget they tried this already

[ScrewMaster]

but how can this guy get a patent on technology from 1958 and claim it as new?

If it's patented in the United States the thing could have been invented in ancient Egypt and the USPTO would accept it.

Please tip your hat in the direction of

[suitepotato]

G. Harry Stine. Model rocketry saint and in his latter days, a fan of Coanda Effect and even more kooky things. You're slowly being vindicated Harry. I owe you much. Rest well.

shame on me, mod parent up!

[HansWurst]

I will read TFA before posting on ./
I will read the pages I link to before posting on ./

This Toy's Been Around for a Loooooong Time

[skidoo2]

Is the US military really this gullible?

Stealth

[caller9]

The effect in question and the shape required to make it work don't really lend themselves to stealth 's sharp edges. Unless that super broad spectrum black paint posted here a while ago works out I guess.

Maybe it doesn't matter for surveillance drones in a backpack field deployment type situation. Possibly more useful than those RC planes they use currently.

Some problems with the design

[spankey51]

Sigh... I came up with this about three years ago... Uncanny, actually: I have sketches that look EXACTLY like this thing.
-The problem I ran into with the design is that it is SEVERELY limited in it's maximum speed.
-As the craft accelerates into clean air, the atmospheric air striking the front surface breaks up the stream of laminar air moving over the surface of the "belly" of the coanda foil... This causes a rapid loss of lift in the front and results in a foreward tumble/catastrophic loss of control due to the imbalance in lift between the rear and front portions of the disk.

I toyed with fixes to allow for much higher cruise speeds, but they added too much weight.

Wierd to see this thing in my sketchbook flying around in a video on the internet... it's like the twilight zone or something.

Back to the Future...

[HeyMe]

It looks A LOT like the Avrocar http://en.wikipedia.org/wiki/Avrocar_(aircraft) from the 1950's. It was supposed to have spectacular performance. Didn't happen. You can do a whole lot of things with models that you just can't duplicate on the full-sized article. I do wish him luck, though.