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Airbus and Boeing are exploring the viability of electric planes

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Re: Airbus and Boeing are exploring the viability of electric planes

#91

Post by Bromskloss »

cagenut wrote: post #23

If you're interested in the electrification of flight check out this episode of Fully Charged: https://www.youtube.com/watch?v=Xe1g1JrRRkY Its kindof like a "roadster" for the sky. I was really impressed by the contra-rotating prop opportunity that becomes possible because of how small electric engines are (for their power).

> I was really impressed by the contra-rotating prop opportunity that becomes possible because of how small electric engines are (for their power).

Did that really have to do with the electric motors? They even gave an example of a combustion engine plane that did the same.

Re: Airbus and Boeing are exploring the viability of electric planes

#93

Post by wongarsu »

gsnedders wrote: post #55
jopsen wrote: post #15

From an engineering perspective how much harder would be to do a cross Atlantic high speed rail: Norway Canada ? Politically, it would probably be possible due to cost and risks.

Even at 350km/h, you're talking an 18 hour train journey. It's just too far, really.

The idea is full of problems, but what is the argument against 18 hour train journeys?

Traveling to anywhere in Siberia involves longer train journeys. Space is much cheaper in trains than it is in airliners and sleeping wagons with beds are relatively cheap in both European and Siberian trains. Restaurants are common in high speed trains. A 18 hour train journey can be vastly more comfortable than a 7 hour flight.

Re: Airbus and Boeing are exploring the viability of electric planes

#94

Post by ShorsHammer »

lumberjack wrote: post #48

It would make infinitely more sense to look into carbon neutral hydrocarbon fuels that could be used in conventional turbofans. Some more material on this topic: https://aviation.stackexchange.com/questions/26910/could-an-...

Another SE link of interest, how much electrical power needed to run a 747 engine:

https://aviation.stackexchange.com/questions/19569/how-many-...

The consensus is ~90 MW.

That's a lot of energy, electric air travel is certainly possible, but it will likely come at a severe cost to speed and endurance.

If we are going to travel slowly would personally prefer autonomous airships.

Re: Airbus and Boeing are exploring the viability of electric planes

#95

Post by skookumchuck »

knolan wrote: post #64
savrajsingh wrote: post #25

It’s just a question of the energy density of batteries vs. fuel. We need a couple more battery breakthroughs before we get a fully electric commercial airliner.

You also expel all that burnt fuel reducing weight was you fly. Some aircraft even redistribute fuel between tanks to control stability and performance. [0] [0] https://www.amevoice.com/blog/1058/airbus-a340-fuel-system-d...

A large gas tank was added behind the pilot's seat in the P-51 to extend its range. But it unbalanced the airplane, and made it difficult to fly. Pilots always drained it first.

The Luftwaffe never figured out that they could have trashed the P-51s if they caught them early enough.

These days, that tank has been replaced by a passenger seat so you can get a joyride on a P51.

Re: Airbus and Boeing are exploring the viability of electric planes

#96

Post by wongarsu »

hengheng wrote: post #19
jopsen wrote: post #15

From an engineering perspective how much harder would be to do a cross Atlantic high speed rail: Norway Canada ? Politically, it would probably be possible due to cost and risks.

Tectonics would like a word with you

The tunnel could be partially floating (or rather bridging over deep parts of the sea floor). Continental drift shouldn't be a big problem over a few decades, you will need some expansion joints anyways.

Re: Airbus and Boeing are exploring the viability of electric planes

#97

Post by DoctorOetker »

ams6110 wrote: post #73
mrfusion wrote: post #71

Earlier quoted context omitted.

I’d actually suggest the opposite. Planes cuuently need overpowered engines just for take off

It will still never make sense until battery energy density increases a lot more. Boost power for takeoff is still going to be cheaper weight-wise burning kerosene than with electric batteries.

probably a stupid question, but since theres landing gear anyway with drag, why can't electrical power be supplied through the wheels? I am thinking something like a tram, possibly with a bottom pantograph?

Re: Airbus and Boeing are exploring the viability of electric planes

#99

Post by mrfusion »

cagenut wrote: post #23

If you're interested in the electrification of flight check out this episode of Fully Charged: https://www.youtube.com/watch?v=Xe1g1JrRRkY Its kindof like a "roadster" for the sky. I was really impressed by the contra-rotating prop opportunity that becomes possible because of how small electric engines are (for their power).

I feel like it would chop up The air too much for the second propeller?

Re: Airbus and Boeing are exploring the viability of electric planes

#100

Post by icegreentea2 »

m_mueller wrote: post #90
ams6110 wrote: post #73

Earlier quoted context omitted.

It will still never make sense until battery energy density increases a lot more. Boost power for takeoff is still going to be cheaper weight-wise burning kerosene than with electric batteries.

How much of a Tesla‘s battery is drained after a drag race? Electric seems to be quite good at delivering boost. See also the current generation of supercars from Porsche, Ferrari and McLaren.

The problem is that then the battery and the entire electric half of the hybrid system is then deadweight for the rest of the flight.

Now that doesn't mean it's not viable, but it's going to be a difficult calculation to make without actually have specs in front of you.

The catapult solutions elsewhere in the thread seem to make more sense.

But once again we're all back to actually having to do the math on these.

Commercial flight is viable because the engineering safety factors and economic margins are so close to 1. This means that changes actually have to be considered carefully, unlike some other fields where the greater safety factors and margins let you get away with more assumptions.

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