Could this 18-motor wing be the future of electric aircraft?

Could this 18-motor wing be the future of electric aircraft?
The truck-mounted LEAPTech Hybrid-Electric Integrated Systems Testbed (Photo: Joby Aviation)
The truck-mounted LEAPTech Hybrid-Electric Integrated Systems Testbed (Photo: Joby Aviation)
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The truck-mounted LEAPTech Hybrid-Electric Integrated Systems Testbed (Photo: Joby Aviation)
The truck-mounted LEAPTech Hybrid-Electric Integrated Systems Testbed (Photo: Joby Aviation)
The LEAPTech experimental wing (Photo: NASA/Tom Tschida)
The LEAPTech experimental wing (Photo: NASA/Tom Tschida)
Rendering of the LEPTech demonstrator (Image: NASA Graphic)
Rendering of the LEPTech demonstrator (Image: NASA Graphic)
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It might look like it was designed by a six-year-old, with 18 motors crammed onto a too-thin wing, but the Hybrid-Electric Integrated Systems Testbed (HEIST) experimental wing demonstrator could be the future of electric aircraft. A key component of NASA'S Leading Edge Asynchronous Propeller Technology (LEAPTech) project, it is designed to test whether electric propulsion can allow for a tighter wing design leading to greater efficiency and safety.

Beginning in 2014, the LEAPTech project is a joint venture of NASA Langley Research, Empirical Systems Aerospace (ESAero), and Joby Aviation. ESAero is the prime contractor for HEIST, which will be tested over the coming months. A 31-ft (9.4-m) composite wing section with 18 electric motors powered by lithium iron phosphate batteries installed on it will be mounted on a truck that will race at speeds of up to 70 mph (113 km/h) across a dry lakebed at Edwards Air Force Base, California.

According to NASA, the number of engines will allow for better airflow by forcing air over the wings, which reduces drag while increasing lift, so the wings can be narrower. In addition, the motors can be throttled individually for more fine-tuned configuration. The hope is that this will lead to a better ride along with lower energy consumption and noise.

The next step will be a piloted demonstrator X-plane under the NASA Transformative Aeronautics Concepts program, which will replace the engine and wings on an Italian-built Tecnam P2006T with the LEAPTech configuration. NASA says that using a production aircraft will make performance comparisons easier by allowing engineers to use an unmodified P2006T as a baseline. It hopes to have the X-plane demonstrator in the air within a couple of years.

"LEAPTech has the potential to achieve transformational capabilities in the near-term for general aviation aircraft, as well as for transport aircraft in the longer-term," says Langley aerodynamicist Mark Moore.

Source: NASA

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Using several small propellers instead of one big one costs a lot of efficiency though, and increases power usage a great deal.
Noel K Frothingham
But if one fails, the results are not as catastrophic.
If they didn't think the gains in efficiency of the overall system had the potential of being greater than the losses incurred by having so many motors, they would not be trying this.
Remember, NASA do have one or two pretty smart people working for them.
Also, with propellers distributed all over the wing span, it becomes possible to model the airflow and lift distribution locally, and this, together with the lower tip speed of the shorter blades might well compensate for the assumed loss due to the the smaller propellers, especially when going fast.
"It might look like it was designed by a six-year-old..."
That would be insulting to many 6-year olds.
NASA or not, That looks awfully top heavy.
Thrust at that height is bound to be tricky- I hope the operator has some experience with airboats and truck driving.
It will be worse if it is autonomous or remote.
On a lake bed, there are irregularities that can create escalating difficulties- The Salt would be better, it is more forgiving.
Th Sand grips,the Salt slips.
Look up the Piasecki 97 on YouTube- a bunch of geniuses with too many moving parts can still fail horribly.
This one shouldn't be as bad,of course, but that Peterbilt is at the high end of it's intended design speed with a top heavy load and high thrust right behind its cab.
They have probably done models,CG and perhaps RC,too.
Still, it just looks like a poorly executed concept to me.
Why is the wing so high?
A low crane cab and a more moderate wing would be a much more balanced approach.
Skyler Thomas
I wouldn't worry about loss of traction. If that was a worry they could always configure pressure sensors in the suspension of the truck with the flaps on the wing in such a way that the lift does not exceed a certain amount. They will be driving in a strait line as well, so loss of traction becomes even less of a problem. They aren't going to be going 70 mph right off the bat either. If they do decide that the risk of losing the experiment is too high before that point, I doubt they would continue as planned.
One thing that does bug be though is the 70 mph measure. They can't reasonably predict what the wind speed is going to be on a given day, and even if they wait until it is the right wind speed there is no guarantee of how long those conditions will last. My guess is that the researchers are are looking at knots per hour rather than mph.
As for the height of the wing, that probably has something to do with reducing turbulence from the truck.
@griffin, I don't think they are trying to make the truck fly.
The Skud
They are supposed to be engineers, but it still seems to me that cumulative efficiency losses per motor would be worse that a couple of bigger motors! If they CAN beat that problem though, it would be a head-turner of a small sports car drive system - after all, they generally come with a large wing already! Make the wing a non-lifting profile and use it just for drive.
It's NASA, so you have to expect they know what they're doing, and the did indead put "Leading Edge" in the title - but putting the props in front, rather than behind, the wing guarantees that you cannot use laminar flow - the propwash over the wing will basically wreck it.
I wonder what benefit they're optimising for? "Optimal flight" is almost certainly not it, but "as good as you can get for a very wide range of airspeeds" might make some sense?
"Empirical" might be the clue here? Maybe they had a huge argument with the CFD people, and decided to make a really-difficult-to-model-in-CFD project to prove to the CFD people that "doing" works better than "thinking"? Or maybe they're helping that mob - getting the CFD to match the experiment would greatly improve the CFD for future uses.
Paul Smith
High enough to get it above the pressure wave created by the truck cab. Likely testing the flow characteristics of the wing.
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