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Comment by paulftw | Hacker News Reader

Helicopters use complex and expensive mechanisms to articulate rotor blades. If plasma can eliminate hinges on wings hopefully it can also be used to dramatically simplify the helicopter design. That'll be a real breakthrough.

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In a helicopter if your engine stops working, you start falling. Falling produces wind on your rotor blades and causes them to spin faster. Blades spinning faster makes you to stop falling. This effect is called autorotation and you control it by varying the pitch of your rotor blades. Autorotation means that you don't automatically die if your engine fails.

With plasma actuators (also quadcopters), battery faliure means death.

"Corke and his team reported that the wind tunnel test item, which used “new actuators that developed 20 times more thrust while consuming 100 times less power, produced a 65% drag reduction.” The Notre Dame researchers have found that introducing a small oscillation whose waves move perpendicular to the air flow path can halt the onset of the so-called near-surface flow instabilities that lead to turbulence."

Sounds like it's already a real breakthrough. After this it may just be a problem of imagining where to put this stuff.

I think the point is that while it's a minor change for classic aircraft (replace some flaps with a plasma actuator system because it's more energy efficient). In helicopters it is a radical simplification and will drop the price and complexity of the key flight system by an order of magnitude.

Will it have a similar effect on quads both small and large? I keep waiting for people sized quad or octocopters so hopefully this makes them more efficient.

Manned multicopters have already happened. [1] MIT has also demonstrated a variable pitch quadcopter. [2]

If they can use plasma laminar detachment and reattachment to somehow simulate a variable pitch propeller, while still getting some weight savings over a design with multiple swashplates, then yes I think it should help the quadcopter design scale up to larger propellers. That's a big if though, since to simulate a negative angle of attack I'm guessing your propeller design would have to be pretty inefficient with all plasma turned off.

I'm not entirely sure why you want this though, since the single large rotor is more efficient. There was a novel design a few years ago with one large rotor for lift and three smaller ones to counter torque and provide control. [3]

[1] https://www.youtube.com/watch?v=L75ESD9PBOw

[2] https://www.youtube.com/watch?v=Vy5Ky50eGJs

[3] http://www.geek.com/science/weve-been-designing-quadcopters-...

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