Bladeless Fans for Aero Benefit?

[flynfrog]

Thanks caito. I was sure in my own head it was feasible but needed some wiser brains to look at it.

Using that method, do you think it could act in a similar way to the old fan car or in other ways to dramatically increase downforce?

no its a much less efficient design

[Caito]

Thanks caito. I was sure in my own head it was feasible but needed some wiser brains to look at it.

Using that method, do you think it could act in a similar way to the old fan car or in other ways to dramatically increase downforce?

no its a much less efficient design

I don't have the least idea about that but I trust you. Only thing I can say is that it should be legal, given the current jurisprudence.

[Lycoming]

It would be legal, but it won't dramatically increase downforce.

The fan is powerful partly because it re-energizes the airflow. When you have a boundary layer, the further along the layer you go, the less energy the flow has due to viscous shear drag. Any sort of ducting will only increase those losses because now you probably will have bends to negotiate as well, which will result in more losses.

Blowing a slot gap to stall a wing is one thing. Blowing a diffuser for more downforce requires high energy flow to make any meaningful contribution.

[MIKEY_!]

There is still a fan with blades in there so it would be illegal. You might still be able to achieve the same effect without blades by ducting the exhaust to the slots on the inside of the hoop rather than fan air. But what to do with the air thus collected? As I understand it the velocity is not very high so the options are limited.

[amouzouris]

one way i could see this working is with the red bull canon hot air outlet...it would probably help with the extraction of the hot air allowing for smaller sidepod inlets....

or is it too unrealistic?

[Dragonfly]

Could someone explain the principle of a bladeless fan?
Because for me the thing on the picture is just a blower, fed with air. To be a fan it must actively suck and move air.
I've seen some similar looking gadgets used to cool the driver in the garage but have always thought they are a variation of a heat pipe with less noise and small gradient between the cool and warm flow.

[stez90]

If they could route air with enough energy from some intakes in hi pressure zones (instead of moveable aero), what about blowing slots on the body to help the flow stay attached (like in multi element wings)?
For example help the flow to travel along the curvature of sidepots, maybe it could be useful for Coanda effect on exhausts or diffuser blowing, allowing to use more "extreme" shapes for sidepots without flow separation..

@dragonfly: IIRC the slot inside the ring is blown from a small hidden fan, the flow (with higher speed than surrounding air) follows the curved shape of the ring (Coanda effect) generating a low pressure area at one side of the ring, forcing the air from the other side to move in that direction.

[hollus]

The "bladeless" fan has blades. It just has them in the base. See at 38 seconds.
http://www.youtube.com/watch?v=t2Q4rZUoR-w&feature=relmfu

[Agerasia]

Actually a smaller version around the air intake would be perfect and instead of fans have a small opening.
I've never understood with ram-air being legal why the coanda effect hasn't been used to a much greater extent.

[superdread]

They are bladeless fans, so called electrostatic fluid accelerators.
You use a ionizer charging the air particles, an electric field to accelerate those particles and an electrode to neutralize by resupplying the particles with electrons. It has some practical problems however (for sufficient added impulse you need a long acceleration capacitor, for high flow large ionizers and neutralizers ).

There was a company actually developing a system for computer cooling (rather low throughput per area and ouput velocity) but haven't hear from them for more than a year.

[n smikle]

I only have limited knowledge in this area and was wondering if someone could give me an answer. Moveable aero regs prevents a lot of innovation, so would one of these bladeless fans, or something like it be allowed and if so, would it have any real effect?

This is just one big annular nozzle.
I employ some miniature versions as blowers at work.There are ejectors. Ones at work use compressed air though.

I have some from these companies....

http://www.exair.com/en-us/Pages/default.aspx

http://www.nortelglass.com/airmoversdetail.shtml

This technology is very old.. just a nozzle. Nothing special.

[rjsa]

The concept behind this is the same as the EBD. Just instead of a fan pushing air trhu that slit you get it hot and fast from the exhaust.

[simieski]

Could someone explain the principle of a bladeless fan?
Because for me the thing on the picture is just a blower, fed with air. To be a fan it must actively suck and move air.
I've seen some similar looking gadgets used to cool the driver in the garage but have always thought they are a variation of a heat pipe with less noise and small gradient between the cool and warm flow.

These cooling devices are just simple jet pumps. They use the Venturi principle to provide a flow of ambient air from a high pressure air source, much in the same way as aircraft escape slides are inflated.