First off a video for how the new Dyson bladeless fans work.

http://www.youtube.com/watch?v=8he8afjQyd8

I've stood in front of these at the local Future Shop and they DO work and work rather well. Someone in another thread brought up the idea of using an EDF fan to feed a Dyson fan ring. Now that may or may not work for pure propulsion but the whole thing got me thinking of the Custer Channel Wing.

http://www.youtube.com/watch?v=-Sn5JL9t_C4

Now what if the idea of blowing and pulling air over the upper surface could be combined with the Dyson principle. Oh sure I know that blown airfoils have been used before. But those were for boundry layer control. The Dyson configuration of a blown slot actually move the air over the wing and SHOULD produce thrust at the same time since the fan is able to push the air across a room. Could this blown slot Dyson technology breath new life into the idea that Custer came up with so many years ago?

Of course with the idea of blowing air over the wing from the slot which grabs and accelerates the free air in front of the wing there's no longer the need for the actual channel which allows the wing to sit close to the prop. So we could go back to a flat wing.

Now here's the catch.... if the blown slotted wing can generate both lift and thrust all at the same time then if the plane sits on the ground at the right nose high angle or if the wing were pivotable then we could use the combined lift and thrust to perform a vertical takeoff. Similarly the plane could slow down and go nose high with ease on the landing approach since with the blown upper surface the airfoil can't stall in any normal sense. Just the reaction air jets for attitude control would need to cut in as the airspeed slows down and the plane transitions into a hover and descent.

The question at hand is will this blown "air multiplier" effect be strong enough to generate the thrust needed to get the lift for VTOL and good forward airspeed or would assistance propellers be needed?

Or am I just blowing hot air..... again

If we forget history -we are doomed to repeat it
Good ol Dyson - The vacuum sales huckster. he now wants to sell a update of the venturi vacuum setup
Don't believe it
The FIRST time I saw it use was on dry cleaning pressess from the 194o's Sane thing without the "airplane wing shape thing
if you ever walked by an old dry cleaner shop you would hear the blast of steam coming from a pipe vented out of doors
scary the first time you heard it
Why did the shops stop using it
simple
Extremely inefficent use of steam and desired vacuum flow was weak from the press -which needed flow thru pads and the garment being dried and cooled
The principle was identical to Dyson' "discovery". -blow high pressure thru venturi- creating a low pressure upstream-
The horrible fan blades which chop up the air (sic) are actually the most efficient method of moving air
Look at the bypass fan setup on current heavy lifters .
By the way
The vacuum needed in dry cleaning is now furnished by large flow vacuum units - EFFICIENCY is the key in today's air movement devices.
Even in air conditioners
The high efficiency air conditioning unites move lots of air at the big thing outside the house and at low pressures the pumps are also designed to uses less electric power
basically less compressing power needed and the less heat exchanging power needed - the less $$$electricy is needed
Th Dyson setup would need one incredible high pressure air pump to make it any kind of a usable thrust unit
Here comes the reality part -again
The more you try to increase pressure or speed from the natural state, (rest) The more the power required at an ever increasing RATE. 4x the power needed to double the speed etc..

As a simple example - a lighter aircraft will always perform better than a heavier one - unless you are using gravity to propel it.

“Inducement and entrainment� of the air? That sounds like the same crap pushed over the years by the Coanda enthusiasts.
In fact, the Dyson fan moves a small fraction of the air of a similarly powered conventional fan and is much noisier according to the reports. As far as the air buffeting is concerned, it simply isn’t an issue unless one is really close to the fan since the air stream quickly smoothes out.
The Coanda based flying machine promoters have used exactly the same arguments for efficiency because this is basically a Coanda device. The principle has been successfully used on a hi-end range hood but that is another thing entirely. http://www.ajmadison.com/cgi-bin/ajm.../AH360720.html
The efficiency claim for the Coanda devices is based on a report of a wind tunnel test done at IIT (Illinois Institute of Technology) which just happens to be my alma mater. I have read that report and it was clear that the ‘aerodynamist’ violated the most basic of procedures by sticking his hands into the air stream, grossly modifying the flow over the test body and distorting the balance readings (his hand affected and accelerated the flow but obviously was not connected to the balance, thus any drag produced on his HAND would not be measured). This test was blatantly unscientific yet the Coanda nuts have latched onto this wonderful fiction (I know one all too well and try to avoid him since he insists on talking about this every time he traps me in a social setting).
I have seen youtube clips of several little Coanda models and they barely can get off the ground. Compare them to any of the little helis you see at the local field doing amazing things at warp speed and it is clear which technology is best.

I attended the Sam Houston Institute of Technology
I learned to detect s h i - at an early age.
Dyson is just another huckster.

"Someone in another thread brought up the idea of using an EDF fan to feed a Dyson fan ring."

I just posted that like 5 hours ago and you forget my name already?

LOL

who?

Well, I didn't want to expose you to the ridicule if this idea went south....OK everyone! It was Amish' that gave me the idea so he's as much to blame as me

Whatever his past foibles the Dyson table top fans I saw running were quiet and were moving a decent amount of air. Now how much current they were using to do this and how much could a regular fan blade move for the same power is a whole other issue.

Even if it won't work for actual thrust at some point I would not mind playing around with the idea of trying it for the "static lift" idea that is central to the Custer Channel Wing concept.

No laughing (snicker)
When I saw Dyson with that lovely accent and that fan-I cracked up -
Snake oil sales at it's very best.

LOL, I feel better now.

Now instead of a plane with a over sized cowl ring, we build a Harrier type model with huge intakes on the sides. Then feed the air into the wings and shoot it out leading edge slots over the wings.

I think you would get more trust if you shot air over the top and bottom of the wing at the same time but I wonder if you would lose the lift?

inducement, entrainment.....all smack of convection

The Custer Channel wing, while unique, if I understand it correctly, relies on increased airflow over the channel part of the wing, due to the propeller. Well, it occurred to me that the velocity behind the propeller is greater than that in front of it and so it makes more sense to put the propeller in front of the wing as it is normally done.

Dyson's fans blow and his vacuum's suck. 

Poor ratings in Consumer Reports.  He brags about mulitple venturies in his vacuums, when actually one is more efficient.</p>

The fan sucks. End of story!

One would think that is a good thing.

Let's all pay $440.00 for a $30.00 room fan.

Shouldn't it be "Dyson's fans suck and his vacuum's blow" instead?

I have always been interested in making a model like that, but it has always been tough to validate numerically. Since you are trying for VTOL, there is no pressure on the lower surface (at a normal high angle of attack the pressure on the bottom is much higher than atmospheric) which means in order to get a similar pressure differential, the required velocity on the upper surface is almost doubled. The Custer wing was only slightly improved over a conventional wing design (the weight of the complex spar ended up almost making the blown section negligible) so it seems like in order to get enough of a Cl to do a vertical takeoff, the air velocity is going to have to be extremely high. It seems like it would work though...blowing across the top of a piece of paper is essentially doing the same thing.<div>
</div><div>And in defense of Coanda devices, there have been numerous successful prototypes, along with hundreds of well-performed studies. There is an entire AIAA book called "Applications of Circulation Control Technologies" that has numerous papers on the subject...and I have personally seen a model obtain a measured Cl of between 5 and 7 on a sting balance (without my hand in the freestream). And they are designed for slow speed, high lift; so comparing them to helicopters is not fair at all.</div>

Actually foutsjoe, so long as the air is moving under the wing, then the pressure will be less than atmospheric (static). The wing only reacts to pressure difference between top and bottom. If the wing is still, then the maximum pressure under the wing can only be local static pressure. The object here is to produce enough pressure difference between top and bottom (lift) to raise the whole machine. The problem then is, with no airflow over the control surfaces, how the heck do you control the attitude of the thing? The old 'raised by its own bootlaces' thing.
Evan, WB #12.

Foutsjoe, my thinking was that if the wing "under" the prop of a regular Custer wing could be made to lift up then if the craft sat at a nose high angle the U wing lifitng up and back would balance against the prop thrust pulling it ahead. The "lift" straight up being the resultant of the prop thrust aimed up and ahead and the lift being aimed up and back.

I'm going to do this at some point but first I need to finish the renos in the new house that will become my retirement workshop. The outside is done now and focus will soon shift to the insides. Almost 1000 sq feet of wood working and model building area Baby ! ! ! ! !

Nice!

The only Coanda devices I have seen -which had any degree of practical application, were fluidic control valves
These were a bit tricky as pressure had to be fairly precise to allow flow to attach to the path(wall) desired
All this other malarky about fans and circular wings was proven long ago to be of little practical value - but then so is lipstick.