/sci/ - Science & Math

>>10294336

>>10294347
:(

>>10294336
just use electricity to convert water into hydrogen and oxygen, then you have rocket fuel.
many fuels can be synthesized without fossil fuels

>>10294372
I don't make the rules.

>>10294375
change them :(

>>10294347
FPBP
Storing electrical energy is just too hard

>>10294386
Batteries function through a chemical process, the only way to increase their efficiency is to change the process to a new one or find some sort of catalyst that increases the efficiency of the existing chemical reaction.

>>10294386
>>10294372
>>10294336
If it makes you feel better I updated the graph.

>>10294336
We did, Google "solar powered aircraft". I think it tops out at like 60 MPH

>>10294336
We can, use Google.

Can anyone tell me how many watts to lift a 100 thousand kilogram spaceship to escape velocity?

>>10294423
this, also fission fuels are significantly higher on the Y axis and a little bit closer on the X axis compared to fusion fuels.

>>10294868
Realistically it depends on how you use them. It's a lot though

You can approximate it with E=MGH

>>10294336
We already do, look up Flite Test or any other RC model channel on Youtube

>>10294336
>>10295197
Also a hungarian cessna sized electric plane crashed last year due to battery malfunction. Cars just stop and you have a few seconds to jump out before it burns to the ground where a plane crashes. We need to solve the dangerous battery problem first, which might be around the corner with the new fluoride batteries

>>10294374
Yeah but hydrogen sucks big dicks to work with
Supposedly methane is where it's at

>>10295202
>fluoride batteries
That sounds like a good idea, sure, sign me up

>>10294336
There are a few electric planes, Google it.

For rockets, please define your question better, there is a electric powered rocket called the electron rocket, it's using batteries to power the pumps for the fuel and oxidizer flow. As for ion engines, they get extremely small thrust, but really good efficiency. But during launch you don't care as much about efficiency, you care more about raw thrust power, so your payload doesn't falls back on the earth. If you want to do that with ion thrusters you would need so much electric power that your whole efficiency aspect just tanks

>>10295330
>If you want to do that with ion thrusters you would need so much electric power that your whole efficiency aspect just tanks
I don't think you can do it with ion engines, the rocket equation is a bitch.

>>10295337
Of course you "can" it's all just a matter of practicality. When you launch a nuclear or fusion reactor with your payload it could be feasible, but at that point you're better off using plasma thruster or some shit like that

>Why can't we make aircraft which use electricity for propulsion or lift?

We can, have you ever seen a drone?

The storage of energy in the form of electricity is not light weight enough to scale well past ultra light weight aircraft, so passenger flights and freight are out of the question.

>>10294336
*farts on your dick*
https://www.abc.net.au/news/2018-01-04/first-electric-plane-passenger-flights-in-australia-to-rottnest/9304424

but it's not common because 1) if you have a heavy battery weight in a car and you accelerate it, you get some back with braking. lifting a heavy weight up in the air in a plane you dont get any back on the way down, so probably not efficient plus 2) having Just-enough-fuel and not much spare is a much bigger problem for planes than cars, 3) electric cars are a meme anyway and don't save shit in environment or money so what's the fucking point or them let alone electric planes

rockets your fucken joking look up power to weight mate

>>10295364
thust-to-weight, more to the point

>>10295365
Asses to Asses
Thust to Thust

>>10295202
>>10295299

I'm in.

>>10295202
>our batteries aren't energy dense enough
>they are also dangerous
>I know; lets make them even more energy dense!

>>10294336
We have the actual thrust producing component (propeller/turbine) working just fine, it's just that driving it with electricity instead of jet fuel is impractical due to battery sizes. There are already tons of personal drones running on battery power, but making something that can fly for hours is still a big challenge until battery tech catches up.

this is a troll post right?

>>10295299
>Flouride

Dont forget your good running shoes.

>>10295740
welcome to chemistry
you want nice things? you're gonna have to play fuck fuck games to get them

>>10294336
There's a project out there to make 1 megawatt electric motors for airplanes that are light enough that you could hold them in your hands if you were moderately fit. Currently the power source will be hybrid, with gas turbines running generators to power it, you still get a gain in efficiency because you can have more distributed thrust. However, the same organization funding this wants some FUCKING CRAZY ultra-high temperature ultra-high pressure heat exchangers for NUCLEAR POWERED CIVIL AVIATION! They want to make nuclear reactors with a high enough power density that they can actually lift all their shielding off the ground.

There's also air batteries which could be competive, fuel cells could be too. Fuel cells can be pretty goddamn efficient, it's just that they need a higher power density.

OP we tried to do that in various ways, with mixed levels of success:

>the USAF's nuclear aircraft propulsion program failed because the DoD got really skittish over nuclear reactors after the SL-1 accident
>NASA's nuclear rocket propulsion program was a success but wasn't deployed because Congress didn't want to pay for it
>ionocraft in general require too much power to be usable outside of space, but NASA did redevelop them into satellite propulsion systems
>wireless power beaming works for aircraft propulsion but usually not well enough unless you have a complicated relay system setup or multiple power plants to buy time from

It works for cars, boats and trains because they aren't constantly fighting gravity and thus only need enough power to overcome friction.

>>10295202
>fluoride batteries

I'm scared but intrigued