Musk-Stark efforts bear fruit?
Airbus and Boeing are exploring the viability of electric planes
111–120 of 149 posts
Re: Airbus and Boeing are exploring the viability of electric planes
#112Earlier quoted context omitted.
There is more than that. Planes become lighter as they burn fuel, batteries don't become lighter as they drain. Lighter planes are more efficient, and most airliners are not designed to land with their tanks full. They have a option to jettison their fuel in case of emergency. It means that just matching the energy density of fuel is not enough, batteries must exceed it. Jet engines are also quite efficient: around 4…
> There is more than that. Planes become lighter as they burn fuel, batteries don't become lighter as they drain. Flow batteries can and open cycle fuel cells do; electric isn't just the kind of batteries that retain reaction products.
I get the fuel cell concept: fuel (H2) and oxygen combine to make water, which is thrown overboard. But, I don't see how this pertains to flow batteries. Generally, the flow battery material (e.g. vanadium oxide) is highly toxic and/or reactive. Do you propose sending that type of material overboard?
Re: Airbus and Boeing are exploring the viability of electric planes
#113Re: Airbus and Boeing are exploring the viability of electric planes
#114The stat that really woke me up to how popular travel was when an aviation magazine once posted that at any second of any day, there are at least one million people flying in an airplane somewhere. That's an entire good sized city full of people who are not in contact with the ground at any point in time you care to pick. And that article was quite a few years old, I wouldn't be surprised if that number has increased…
It's said that 1000+ Boeing 737 alone are airborne $NOW.
Over 1200 737-800’s alone
Re: Airbus and Boeing are exploring the viability of electric planes
#115Earlier quoted context omitted.
But that will never happen in the USA due to the influence of the oil industry.
US wind energy production has increased eight fold in 12 years. The US has greater wind energy production capacity per capita than Norway does for example. Hydro power is an impossible resource to perpetually manufacture more of. The US has heavily tapped out its potential in hydro. First it's difficult/undesirable to manufacture a new source of hydro once you reach saturation, and second it's arguably a terrible ide…
Wouldn't a country with vast access to hydro power be inclined to not invest in wind? And why cherry pick wind power anyway?
Re: Airbus and Boeing are exploring the viability of electric planes
#116Article says that the electric powered planes need shorter runways, why is that?
Instant maximum torque most likely. I guess they are assuming equal or less weight for the plane
Yeah the torque is probably the reason. From experience, if you stand on your brakes and throttle to take off power then let go your take off performance is better. It's part of the short field take off procedure.
Re: Airbus and Boeing are exploring the viability of electric planes
#117Earlier quoted context omitted.
> Takeoff is the hardest part requiring the most power, unfortunately. So, we just need a catapult system for commercial aircraft (like used on aircraft carriers, only lower acceleration since you are doing it to reduce the amount of energy needed from the engines, not to shorten the take-off distance.)
Why not something similar to railgun but at a slower speed. This would involve few things on the plane. The draw back is that airports needs to install this system. During take off, if there is a problem, the system could be stopped. Perhaps it's not usable in this context ?
Magnetic media on the plane might be unhappy.
Re: Airbus and Boeing are exploring the viability of electric planes
#118Earlier quoted context omitted.
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.
Actually the aux tank wasn't added to the Mustang purely for range. A big factor was helping to balance out the heavier Merlin engine. Pilots would typically leave about 1/3 of the tank to keep ideal balance and have an emergency fuel reserve. Typically by the time they had taken off and made the climb to altitude they had burned enough fuel from the aux tank (about half) to be in reasonable "fighting trim". Would've…
Interesting. I was told this by a former P51 pilot. He also said sometimes lone Ju-88s would sneak in at low altitude and pick off B-17s taking off or landing when they thought they were safe.
Re: Airbus and Boeing are exploring the viability of electric planes
#119It 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.
Megawatts is a power unit. To sustain 90MW for a 4hr flight you need a battery that can provide 360MWh of energy.
Anyone care to do the numbers on how much a lithium ion battery would weigh to be able to deliver 360MWh, and remember if you want to use it more than once you can full charge no discharge it.
Re: Airbus and Boeing are exploring the viability of electric planes
#120Earlier quoted context omitted.
You may be interested in the Norwegian TV series "Occcupied": https://en.wikipedia.org/wiki/Okkupert The premise is that Norway develops thorium reactor technology and ceases all fossil-fuel production. And then is clandestinely and later openly invaded by Russia, with the blessing of other countries, to seize oil and gas production facilities and forcibly re-open them.
Oil is always a liability. It would be better to claim you ran out. But the Russian subearth nuclear boring machines don't need to invade.
>Russian subearth nuclear boring machines
The what now?