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Author Topic: How does the Dyson fan work?  (Read 17709 times)

Offline BenV

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How does the Dyson fan work?
« on: 06/11/2009 10:27:14 »
It's a lovely bit of (expensive) tech, but how does the Dyson bladeless fan work?

http://www.dyson.co.uk/store/fans.asp

...and it in action...

« Last Edit: 29/11/2009 10:14:50 by chris »


 

Offline BenV

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Re: How does the Dyson fan work?
« Reply #1 on: 06/11/2009 10:29:24 »
Actually, I've just found it - serves me right for asking the forum before researching it properly myself!

http://www.dyson.co.uk/technology/airmultiplier.asp#HowItWorks
 

Offline Nizzle

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Re: How does the Dyson fan work?
« Reply #2 on: 06/11/2009 12:06:01 »
I think this categorizes as advertisement in disguise! ;)
 

Offline Freeman

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Re: How does the Dyson fan work?
« Reply #3 on: 20/11/2009 08:34:57 »
However, for safety reasons, it seems advantageous to have a blade-less fan around little kids and, to reduce distractions, a fan with no/low visual, aural and tactile "signatures".

Its all good to have a bladeless fan around small children.But....to have a overpriced fan that has the noise output of a vacuum cleaner is something that will even have the dog run for cover ;).

And last but not least - Less airflow that that of a regular table fan of same size.
 

Offline chris

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Re: How does the Dyson fan work?
« Reply #4 on: 29/11/2009 10:14:19 »
I'm surprised they can use terms like "air multiplier amplifies surrounding air" - because this suggests that the amount of air is physically increased ("amplified") by the fan, which is absolute rubbish. Air movement might be amplified, but as has already been pointed out above, this is merely a passive effect secondary to the movement of a primary airstream.

I think this is a bit misleading. A shame, because Dyson's brand is built around a strong scientific message. Once the scientific message is distorted then the brand is devalued.

Chris
 

Offline CycleGuy

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Re: How does the Dyson fan work?
« Reply #5 on: 04/08/2015 06:23:43 »
Coanda Effect... the tendency for air to "stick" to nearby surfaces, and to be dragged along with a separate moving air stream.

I've been researching this for use in a different application... I'll be building a trellis frame for my bike soon (a high-fuel-efficiency project), along with an aerodynamic body. Part of making the bike aerodynamic will be having a venturi scoop opening at the front of the bike to duct the air that is stalled there to the back of the bike (and thereby alleviate some of the pressure drag).

That air will go through the engine compartment and will be used to cool things in there (although it won't be used to cool the radiators, two separate ducts will be used for that, the ducts that help to alleviate cross-wind effects on the aerodynamic body). That heated (and thus expanded) air will then go through a Coanda nozzle much like in the Dyson fans (except made of metal), which will be powered via the engine exhaust, and will exit into the wake of the bike (thus filling the wake and helping to alleviate wake drag).



It's hoped that doing things this way will not only act to reduce pressure and wake drag, but will actually provide a bit of thrust, although there's no way to tell if it will until it's tried.
 

Offline chris

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Re: How does the Dyson fan work?
« Reply #6 on: 04/08/2015 09:17:02 »
Sounds like an exciting project; I'm not quite clear where the exhaust goes through and where the coolant air goes?
 

Offline CycleGuy

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Re: How does the Dyson fan work?
« Reply #7 on: 04/08/2015 12:53:16 »
Sorry, I didn't make it clear. The two black objects in the cross-over ducts are the radiators.

The engine exhaust will be piped to the back of the bike and into a Coanda Effect nozzle (where the fan in the Dyson unit would be). The engine exhaust will then drag the air out of the engine compartment (which is pushed in via the venturi scoop at the front of the bike) into the wake of the bike.

The Dyson fan only pushes about 42 CFM. My engine pushes upwards of 67 CFM at WOT, so the Coanda Effect nozzle I'll be using will be about the same size as the Dyson fan's.
« Last Edit: 04/08/2015 12:54:59 by CycleGuy »
 

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Re: How does the Dyson fan work?
« Reply #7 on: 04/08/2015 12:53:16 »

 

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