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NASA Unveils Plans For Electric-Powered Plane (techcrunch.com)
An anonymous reader quotes a report from New York Times: A new experimental airplane being built by NASA could help push electric-powered aviation from a technical curiosity and pipe dream into something that might become commercially viable for small aircraft. At a conference on Friday of the American Institute of Aeronautics and Astronautics in Washington, Charles F. Bolden Jr., the NASA administrator, announced plans for an all-electric airplane (Warning: source may be paywalled) designated as X-57 and nicknamed "Maxwell," part of the agency's efforts to make aviation more efficient and less of a polluter. "The X-57 will take the first giant step in opening a new era of aviation," Mr. Bolden declared. Maxwell is equipped with 14 electric propeller-turning motors located along the wings, which will all be used to create sufficient thrust during take-off and landing. Only two large motors on the tips of the wings will be used once it's up in the air. The plane is a result of NASA's "New Aviation Horizons" initiative: a 10-year program to create a new generation of X-planes that will make use of greener energy, use half as much fuel, and be half as loud as commercial aircraft in use today.
The issues with electric planes have been beat to death here, this NASA plane appears to have no solution for any of them.
In two days .
I'm just glad they completed all their work done on space exploration so they can do more important things like battery operated planes and AGW alarmism.
triggering the Beatles: http://www.azlyrics.com/lyrics...
let us hope nasa will waste lost of money trying out all the inefficient ways of making electric planes.
then hopefully russians will create cheap and effective electric planes that everyone (even the usa military ) can borrow, as they do with human space travel (again even usa military use russian rockets now ) .
meanwhile eion musk will blow lots of hype trying get his cronies in usa government to give him money to make electric planes too(especially ones that fly on social media to give his fanboys much needed orgasms). as with all his projects this will be a subsidy worthy cause, even without crony capitalism.
12 engines as deadweight and dragging props, that doesnt seem very efficient ? Even with foldable props, they will induce a significant drag. I am sure NASA can come up with a better solution for extra power needed for takeoff.
So they have 12 extra motors/props just for takeoff, that add both weight and drag? Why don't they just use one motor and drive one of the wheels against the ground?
You're forgetting that with the extra props across the wing, you need a much much smaller wing, and can have a wing with much higher aspect ratio*. The reduction in wing area and increased aspect ratio more than offsets any drag from the multiple (folded) props during cruise.
*Those props aren't there for thrust, they are for increasing flow velocity over the wings.
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
GP also ignorantly fails to understand that props efficient in high speed flight are inefficient at low airspeed and vice versa, so stowing climb props is a very good choice for an electric airplane.
The fact that it needs so many motors just illustrates how inefficient electric motive power really is. Before you say, "Well, what about trains?" I say, yeah, but every car on the train has motors in the trucks.
RTFA. Max speed is 175KT, not exactly "high speed". NASA also admits this won't be viable for commercial service, basically a hobbyist plan for short flights with very little payload.
Bottom line though is that NASA is and has always been a PR machine. An all electric plane is a warm fuzzy story for people to read.
"Conventional" aviation supplies a product for market demand: high-speed, low-cost transportation. Low-mass, high-energy fuels make it possible: primarily kerosene, with some use of high-octane gasoline. Right now, electrical power will never replace hydrocarbon fuels because the energy density
energy unit / mass unit
is too low. Even worse, the
cost / energy unit
for batteries exceeds the hydrocarbon
cost / energy unit
"price density". Yes, battery aviation now exists - with government subsidies, and yes, battery aviation fans will howl that government subsidizes hydrocarbons, etc. etc. etc. Hydrocarbon subsidies should end. This does not change the fact that battery energy density will never exceed hydrocarbon energy density.
Now, maybe steam has potential:
https://www.youtube.com/watch?v=nw6NFmcnW-8
Take an electrified Amtrak train from DC to Boston. The cars are passive, all the pulling is done by the engine(s) up front.
The article states that the Maxwell X plane is a hybrid and goes on to detail it is electric propulsion and battery powered. That doesn't sound like a hybrid to me. I can only guess they either used the term in error or were think of future concepts.
Interesting I would guess pure electric aircraft make up the majority if you include hobby quadcopters in that definition. I mention that as I think the takeaway from the article is that electric aircraft are practical in some niche areas and NASA's work will widen those niches. The changes need for EV cars to replace ICE are evolutions in batteries and is already close to the tipping point, but It is going to take some truly impressive breakthrough in battery technology before your will see traditional commercial jets like the A320, 737, 767 or A380 replaced. My guess we are are years, not decades, away from cars going all electric but for aircraft we are probably still talking decades.
hah, even better, look up "climb prop" and "cruise prop" and realize there's a huge difference between the optimal pitch for 80 kts and 130 kts. (climb speed v.s. cruise speed). Considering that tip speed is close to 540 kts at max RPM, that's an 8% difference in speed which is significant.
> GP also ignorantly fails to understand that props efficient in
> high speed flight are inefficient at low airspeed and vice versa,
> so stowing climb props is a very good choice for an electric airplane.
Howsabout variable pitch propellors??? They've been around since the 1920's, and have been in practical use since the 1930's https://en.wikipedia.org/wiki/...
Rev up 2 or 4 engines (admittedly a bit inefficient) for takeoff, and then back off to more efficient speed for cruising. 2 or 4 larger engines are cheaper and more efficient than 14 smaller ones. A bonus feature is that many "variable pitch propellors" can change pitch to *REVERSE* thrust. This is useful for backing up out of a hangar, as well as providing braking during landing on short airstrips.
I'm not repeating myself
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