DaveK
Well-Known Member
I think when you look at the mass flow needed through those generally small ducts to lift a human carrying craft this won’t work. The exhaust velocity would need to be very high. Seems like another Silicon Valley unicorn.
=can be avery form,circular, aso...those bladeless ducts
^^^^^^ THIS guy needs to be de-platformed and sent off somewhere where he can think about all the harm he's doing to the Silicon Valley economy by callously putting common sense in the way of commerce !Correct me if I'm wrong but "air amplification" ≠ thrust amplification. It simply spreads the energy of the high velocity stream over a wider area. You get a larger volume of moving air but at a lower velocity. I would think a turbofan does this far more efficiently.
It apparently is possible use gas/fluid under pressure to entrain additional gas/fluid in a "thrust augmenting ejector"and thereby produce more thrust compared to just jetting the high pressure gas by itself ( more here: Anybody want to build one of these?).Correct me if I'm wrong but "air amplification" ≠ thrust amplification. It simply spreads the energy of the high velocity stream over a wider area. You get a larger volume of moving air but at a lower velocity. I would think a turbofan does this far more efficiently.
I looked at this years ago. It's a silly idea!![]()
Super Air Amplifier
Using a small amount of compressed air as their power source, Super Air Amplifiers pull in large volumes of surrounding air to produce high volume, high velocity outlet flows to circulate air, move smoke, fumes and light materials.www.exair.com
=how it works...
Taking my post above, if we use 12' wing panels with a slot the same width as the 8" amplifier I used above then when we fit (8" x π = 25.12") into (144" x 2) is 11.46 times that we need to multiply the cfm and hp requirements for the wing slot.OTOH, the inventors appear to have a flying model propelled by the Coanda phenomenon. The sailplane test aircraft is of unknown size, perhaps a half-scale RC model, which operates in more or less the same flight envelope as a small homebuilt plane. If so, this proves the concept works for a plane of comparable size to a homebuilt, regardless of the source of the compressed air, which may as well come from a pressure bottle.
So, assuming Coanda propels this small plane (if not, what else propels it?), we're down to asking what source of compressed air and ducting geometry is most efficient, and how all this compares to a conventional engine/prop.
And, are Coanda nozzle/slots limited to oval cross-section boxwing applications, or can such nozzle/slots be fitted to, say, a hollow conventional wing or aileron? In other words, why not dispense with the twin oval thrusters, and simply install the nozzle/ducts on the upper surface of the wing?