Wednesday, June 29, 2011

VoltAir - Electric Airliner

(Fast Company)

VoltAir made a showing at the recent Paris Air Show, on the same stand as the incredible Concorde-of-the-future Zehst space plane, and though it looks much more conventional, it's almost (if not actually more) important for the future of travel. For though Zehst and other craft like it may shrink the globe with super-fast travel, it's aircraft derived from VoltAir that could change the world sooner. Because VoltAir is a zero-emissions airliner for the rest of us — an all-electric alternative to the planes you've always flown in.

VoltAir's magic is all about its pusher-prop ducted fan, and the electric motors that power it. The prop's design is a twin co-axial contra-rotating design, delivering excellent propelling power very efficiently. But what's truly clever are the engines, which would be made of high-temperature super-conducting materials. The engine would be bathed in liquid nitrogen, to drop its temperature to the right operating zone for the wiring which, unlike the copper wiring in a traditional motor, actually only works if cooled. Though this adds a structural burden to the design, it has one astonishing upshot: Superconducting motors would waste almost none of the electrical energy pushed into them, making the plane ultra-efficient.

The VoltAir makes use of plenty of other tricks in its design, though. The airframe would be made largely of composites which makes for incredible strength and significantly lighter weight. The wings use the same advanced curling wing tip that Boeing's employing on the 787 Dreamliner — they're better at preventing drag. And its unusual bullet-like shape means the drag vortices caused by the body itself is actually gobbled down by the pusher-fans, which also creates better aerodynamics.

The problem of recharging the thing — you can't have your electric plane plugged in for 16 hours after each flight — is also neatly solved with a trick of the battery design. They're mounted in the cargo hold, so they could be swapped in and out in the same way as a pallet of cargo is. This also has the side-effect of speeding up ground operations compared to refueling a conventional jet, and that saves money (though we do wonder if that amazing refillable rechargeable cell idea would be a better fit to the VoltAir design).

All of this is extremely plausible, even those novel batteries, and VoltAir is, in many ways, just a rethink of a small airliner. There's just one flaw: The tech to make the electric motors doesn't quite exist yet. It's not far off, though, and EADS — the designers of the plane — think it's possible they'll be available relatively soon (definitely sooner than the far distant first-flight of Zehst, for sure).

(Kit Eaton - Fast Company)

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