Exploring the Potential of Electric Jet Engines for Future Flight

[1oldman2]

I came across this item today, the concept sounds very interesting, however the "electric jet engine" may be a while in development.
http://www.nasa.gov/centers/armstrong/features/X-57_fuselage_arrives.html
http://www.nytimes.com/2016/06/18/science/nasa-electric-plane-x57.html
The steps taken by NASA will not translate into all-electric cross-
country jetliners. But the agency hopes the technology can be
incorporated into smaller, general aviation and commuter aircraft some
years from now.

quoting Sean Clarke of NASA's Armstong flight research center, "I think all-electric would be a stretch for jetliners,"

 

[Simon Bridge]

They are experimenting with reducing power requirements ... this is a concept aircraft (prob not even that far along) only.
The main issue with electric aircraft is the energy dencity: batteries are heavy for the amount of energy they can store, so electric aircraft have issues with range.
Still ... it's the sort of thing to expect as fossil fuels increase in price down the track.

 

[1oldman2]

The main issue with electric aircraft is the energy dencity: batteries are heavy for the amount of energy they can store, so electric aircraft have issues with range.

It will be interesting to see what developments come from this, in electrical storage as well as aircraft materials/design. I did notice all the E-aircraft seem limited to about one hour of flight time, that will change as R&D keeps chipping away at the issues involved.

Still ... it's the sort of thing to expect as fossil fuels increase in price down the track.

This as well as emissions and noise pollution are very high on the list of driving factors behind the programs in everything I've read so far.
I'm still trying to figure out if I've missed something where the terms "electric and jet" get used, I can't reconcile the notion of a jet engine(which to me is combustion) and electric motors, It seems writers are using the term jet as a euphemism for any larger passenger aircraft rather than one specifically powered by a jet engine (or possibly turbine over electric ?). One things certain these programs are going to be keeping a lot of engineers busy for the foreseeable future.
Here is another write up from a couple of years ago. http://www.scientificamerican.com/article/impossible-electric-airplane-takes-flight/
A series of lithium-ion batteries fitted into the wings of the plane are the
sole power source for the E-Fan's two 30-kilowatt electric motors. A 6
kW electric motor in the main wheel provides extra power during
acceleration and taxiing to reduce electrical power consumption on the
ground.

But despite its highly energy efficient design, the E-Fan only has a
one-hour range, which means it cannot leave the vicinity of an airport.
To combat range anxiety, the plane is outfitted with a backup battery for
landing purposes and a parachute that can be deployed as high as 2,000
feet.

"We're trying this. It's not to enter the business of small aircraft," Botti
said. "It's to learn to make a new business."

Airbus Group's ultimate goal is to make a 70- to 80-person hybrid-
electric commuter jet with three hours of range in the 2050 time frame.
Initial designs of the E-Thrust aircraft show the plane with six electric-
powered fans that will be powered by a gas-fueled energy storage unit
during the ascent and cruise phase and then glide using electric power
alone while descending.

 

[Simon Bridge]

You can use an electric arc to heat air in an electric jet engine.

 

[1oldman2]

You can use an electric arc to heat air in an electric jet engine.

Interesting concept, I haven't come across that, thanks. I'm curious about such a systems efficiency, can you recommend any sites or articles that would be available on the subject ?

 

[1oldman2]

This must be the design mentioned earlier. https://www.google.com/patents/US2585810
http://www.electric-vehiclenews.com/2009/07/will-plasma-jet-engines-ever-replace.html

 

[Simon Bridge]

No idea... i imagine it is as good as mixing fuel and air in terms of getting requisite expansion.
The main issue being the energy density of the source.