A. Hypothetical scientific question?

Zaanix · 2020-06-09T00:49:30+00:00

If I'm picturing this properly, no.

The atmosphere you use for any aerodynamic propulsion will impart the kinetic energy onto the far surface of whatever container is keeping the atmosphere in.

That and there is the energy input to spin the control surfaces could easily just be used for a conventional rocket engine.

The fewer moving parts the better.

DangZagnut · 2020-06-09T00:54:02+00:00

If you vent internal air outside, it will act like a thruster and move the ship to some extent. Just like any other rocket propellant system.

If it was all inside the ship, it would work just like a fan. Where the air pushed out, and the force going the opposite direction are going to cancel each other out.

If you were just floating inside the ship, and then use a propeller fan in your hand it would move you around. A little.

But you don't want to vent your atmosphere outside and instead use some other fuel that isn't the air you breathe, and just running a fan inside pushing air around is going to do that, just blow air around.

Sailing ships have external wind affecting the sail, creating an airfoil like an airplane wing, and you fly toward the wind (if you're close hauled) with the keel providing water force to keep it from just pushing sideways, so the ship squirts forward toward the wind like squeezing a tomato seed in your fingers.

but there's no external force affecting a space ship.

You could use solar wind, that's provided externally to move a space ship and sail through outer space that way.

PrestigiousGreen3 · 2020-06-09T00:56:08+00:00

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PrestigiousGreen3 · 2020-06-09T01:11:11+00:00

[deleted]

GoodMan_Gone · 2020-06-09T10:13:57+00:00

Damn, OP! You made me think about this for hours now. I love it. As I see it, you're proposing the principle of building a giant propeller on a sail boat to create it's own wind?

So if you have a rocket/ spaceship: build a propeller inside, make a huge bulb in the nose and even build a sail in the interior tucked to the hull. Let it blow and it'll generate kinetic energy. Make the propeller engine solar powered with panels on the outside. Have the whole thing orbit around the sun until it's accelerated enough to propel to the intended target? I'd say in theory this could work. The smallest acceleration is acceleration in space. Given enough time to build up kinetic energy the speed would be enough to go somewhere.

I only see lots of practical problems though.

1 most energy is wasted on rockets for escape velocity. I don't think your construction could ever build up enough kinetic energy to escape the gravity well of Earth. So you need to propel the whole thing into space first. Better to add the weight of the propeller, engine en solar panels in extra fuel to get the wanted kinetic energy in a heartbeat.

2 So build the whole thing in space? OK. But still the propeller/ engine is a moving object. So it'll wear and tear and the life span is too limited. Also it'll generate heat which you can get rid of very difficultly. Even in an unmanned ship the heat build up will eventually be too much to sustain it.

3 If 1 and 2 are circumvented somehow you have the problem of slowing down once reaching the desired destination. It won't have the same solar power to "quickly" slow down. Provided the installation hasn't been worn out already. So you will overshoot the destination

4 the huge nose will be far more vulnerable to micro meteorites and other space debris.

PrestigiousGreen3 · 2020-06-09T01:10:17+00:00

Wish i could discuss this longer but I'm off to stack shelves. Later brothers

Wisdom_of_a_Khan · 2020-06-09T02:49:21+00:00

If I understand what you're asking correctly.

Anything that acts entirely inside the ship wouldn't do anything but move air around inside the ship, Whether it's a propeller or impeller doesn't matter, you can generate force by pushing air backwards but once it hit the back of the ship the force would negate itself by leveraging equal force in the opposite direction of the impeller.

If the discharge of the impeller is directed outside of the ship it might generate some forward movement but you would deplete the atmosphere of the ship.

MethaCat · 2020-06-09T09:34:13+00:00

I think you would need far more force to control its direction, so maybe you can do it but I think it would be very inefficient. I think a wind sail works here on earth because the surface limits its possible directions. Just a thought, not really a rocket scientist.

The_2nd_Bob · 2020-06-10T22:30:15+00:00

That is, effectively, what a reaction wheel is. While it doesn't propel, like fuel, it does help with satellite orientation. Similar to a helicopter without a rotor spinning out of control... satellites have four reaction wheels to keep a satellite oriented in NADIR pointing.

Ody_ssey · 2020-06-09T06:11:27+00:00

Internal force cannot cause momentum no matter what you do inside. Even if you explode a bomb inside an indestructible spaceship, spaceship will not move from its position at all.

FYI, propellor inside a closed system with air cancels out reaction of pulling air from one side and pushing air out from another side. That's why ceiling fans don't vibrate at full speed.

PrestigiousGreen3 · 2020-06-09T11:48:06+00:00

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PrestigiousGreen3 · 2020-06-09T23:29:37+00:00

Imagine an impeller either wind or fluid that exhausts from the sides instead of front to back. Encasing that in a cone specifically cycling the air or fluid out the sides toward the narrow tip of the cone back to the intake via the top of the impeller. Combined with acoustic propulsion. Not saying it would work just a thought

Title	A. Hypothetical scientific question?
Author	PrestigiousGreen3
Upvotes	12
Comments	39
Date	June 9, 2020 12:42 AM UTC (6 years ago)
Subreddit	Posted in /r/MGTOW
Original Link	https://old.reddit.com/r/MGTOW/comments/gzc9rw/a_hypothetical_scientific_question/
Archive Link	https://theredarchive.com/r/MGTOW/a-hypothetical-scientific-question.672318 https://theredarchive.com/post/672318

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