Science The bladeless fan

[EtherDragon]

Invented by the same man that created the Dyson line of Vacuums...

http://www.livescience.com/technology/091013-dyson-fan.html
http://www.livescience.com/common/media/video/player.php?videoRef=LS_091013_dyson-airflow

I wonder if this could somehow be adapted to rocketry to allow a rocket to behave more like a jet engine when in the atmosphere...

~ED

 

[insane_alien]

the are called electrohydrodynamic thrusters. they wouldn't be good for rockets as they are pretty low thrust things.

 

[Dig Gil]

From what I've read this is not like a EHD thruster these apparatus use huge voltages.

 

[insane_alien]

ah right, this thing uses an impeller.

in that case it wouldn't be much different than sticking a jetonto your rocket.

fine in the atmosphere but dead weight 99.99% of the time.

 

[C3PO]

ah right, this thing uses an impeller.

No. You can see how it works in the video. The "fan" has no moving parts. It's really a cool looking ejector. The smart thing about it is that it produces very laminar flow.

 

[Hielor]

No. You can see how it works in the video. The "fan" has no moving parts. It's really a cool looking ejector. The smart thing about it is that it produces very laminar flow.

The impeller is in the base.

 

[Dig Gil]

I'd like to know what's the "impeller" actually.

 

[Hielor]

I'd like to know what's the "impeller" actually.

A fan inside a tube.

If you read the article:

Air is pulled into the machine's cylindrical base with an impeller that draws from jet-engine technology. The air rushes up into a hollow ring. The air is then forced out of a 1.3-millimeter-wide slit (less than 1/16th of an inch) that runs all around the ring.

 

[Andy44]

This thing has moving parts in the base.

Hype fail.

 

[agentgonzo]

This thing has moving parts in the base.
Hype fail.

Even though it does contain fan blades, they are entirely enclose and away from the actual blowey part of the fan, so whilst saying it does not contain blades, I can see why they say it does. Not sure that it's a hype fail or not. Lamination of the air flow aside (which for the average office fan isn't all that important) it would be interesting to see how much air movement the fan can get compared to a normal desk fan for the given size/noise level. With a much smaller impeller size than the actual 'fan-head' I can imagine that it would have to spin faster, giving a larger noise level (quite important for a desk fan) than your standard desk fan.

The lack of buffeting and laminar airflow could have good applications for wind tunnels, if this technique is not already used.

 

[tblaxland]

Hype fail.

Yes, especially hype fail for a HVAC engineer. I have just come home from a function where an architect was raving about these fans. Our response was "well, it sounds like an old fashioned induction unit to us." "No, no," he said, "look it up on Google, this is brand new technology". My assessment is that it is the same thing but in fancy new packaging. I would be most interested see what sort of induction ratios are acheived and at what sort of power levels.

 

[EtherDragon]

My thought using Jet Fuel / Rocket Fuel to create some thrust where the air "nozzle?" is currently - creating the initial laminar flow along the ring - where atmospheric air would magnify the result.

It occurs to me, though, that if you change the shape of the tube - and put the gas expansion chamber on one side - you essentially end up with a Scram.

 

[JamesG]

Yeah, its pretty much the same principle as a scram jet. Or takes advantage of the same phenomenon anyway.

Its far to subtle for propulsion on its own. A ducted fan is an order of magnitude more powerful than an induction tube can be.

Might be a good application for a blower in a life support system though if it proves to be lighter, more energy efficient, and have a longer service life (smaller impeller motor and bearings).

 

[tblaxland]

It occurs to me, though, that if you change the shape of the tube - and put the gas expansion chamber on one side - you essentially end up with a Scram.

My understanding is that scramjets do not use induction, or even a bypass. Like this:

I think that the nozzle from the OP would not be suitable for supersonic flows. At supersonic speeds the flow needs to expand as it passes through the nozzle, not contract (think aerospike or De Laval nozzle).