this post was submitted on 09 Nov 2024
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Showerthoughts

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I flew for the first time on a plane last week and I've seen planes take off at the airport. It looks crazy. But being on one is totally different like holy shit. The thing just FLIES. It just.... Soars... Through the sky! Like whoa man. Wtf... It's crazy. With how much these things weigh, it's insane to me the thing can just go up and bam, there we are, we're flying now. Like wow... Dude crazy.

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[–] [email protected] 7 points 5 days ago* (last edited 5 days ago) (3 children)

boy do I agree.

I fly a lot, and I think about this a lot. it's absolutely nuts.

I saw a diagram once explaining how planes fly, this is a good explanation of that:

"Airplane wings are shaped to make air move faster over the top of the wing. When air moves faster, the pressure of the air decreases. So the pressure on the top of the wing is less than the pressure on the bottom of the wing. The difference in pressure creates a force on the wing that lifts the wing up into the air."

so that's floating around the back of my mind while I sit in my air chair and think:

"and there we are.

We are climbing into the air again in the big flexible metal tube.

The wings have flex and they almost look like they are flapping in the wind right there.

well, this is crazy again"

approximates my thought process each time I fly.

[–] [email protected] 3 points 5 days ago* (last edited 5 days ago) (1 children)

Yeah that's mostly bullshit.

Your arm flies when you stick it out a window, and it isn't shaped like shit, so does a piece of paper.

It's basically like a sail, but horizontally instead of vertically, the onrushing air hits the bottom at an angle, is deflected down, and bumps the wing up.

The rest is just to try to reduce drag on the top (super-critical wings attempting to maximize laminar flow, or at least make the disconnection as far back as possible so turbulence creates the least drag on the wing.

[–] [email protected] 3 points 5 days ago* (last edited 5 days ago) (1 children)

I'm partial to the Newtonian explanation myself, I was explaining my interest the first time I saw an illustration of the Bernoulli principle.

in fact, I just wrote about The Newtonian explanation a few minutes ago:

"the Newtonian makes more practical end complete sense to me sense to me as an explanation for a lift.

maybe the confusion comes from calling the motion of pushing air down "lift"

push-off.

hm. what the heck is an appropriate antonym for lift...

spring-hold.

oh, buoyancy?

maybe we should switch our talk from lift to buoyancy.

rather than generating lift, velocity through the air generates aerodynamic buoyancy due to the increase in downward pressure, or rather the compressed air beneath the airfoil."

[–] [email protected] 3 points 5 days ago (1 children)

Sorry, as an engineer, this whole "shape of a birds wing makes air move faster over it" pisses me off to no end.

Airfoils are shaped the way they are for drag purposes, not whatever crazy things they say, we could make them like massive triangles and they would still work.

[–] [email protected] 2 points 5 days ago* (last edited 5 days ago) (1 children)

sure, i get it.

he did come up with that half explanation 250 what years ago, so I'll give him a pass.

kind of a bummer that a half explanation is his most famous 'discovery" even though he did so much

[–] [email protected] 3 points 5 days ago

No, yeah, Bernoulli was a genius who did a lot otherwise, he should be remembered for all his other scientific contributions..

But you fuck one goat...

[–] [email protected] 2 points 5 days ago (1 children)

If flying is crazy, then by the logic explained here today, controlled landings are even crazier.

[–] [email protected] 2 points 5 days ago (1 children)

I personally think rising is more impressive and spectacular than falling.

[–] [email protected] 1 points 5 days ago (1 children)

See, I think a controlled descent is more impressive. If you're on the ground, and you want to be 5 feet in the air, but you fuck up and go 150 feet in the air instead, well.....no big deal. Everybody on your plane is now screaming in fear, because it's very noticable that their pilot is incompetant, but they ARE screaming. Because they're alive.

But if you're coming down, and the ground is 5 feet below you, and you fuck up and drive it 150 feet into the ground......the only people screaming are onlookers.

"OOOOH MY GODDDDDD!!!!! THAT PLANE JUST CRASHED AND BURST INTO A FIREBALL!!!! EVERYBODYS DEAD!!!!! MEN! WOMEN! CHILDREN! EVEN BABIES!!!! EVERYBODIES DEAD!!!!"

And then the news does a report on how drunk the pilot was.

[–] [email protected] 2 points 5 days ago

"THAT PLANE JUST CRASHED AND BURST INTO A FIREBALL!!!!"

not the controlled landing that I was referring to, but I understand your comparison of the consequences.

"and the ground is 5 feet below you, and you fuck up and drive it 150 feet"

this is my favorite part of your scenario. a pilot literally less than a second from touching the ground glances out the window and thinks " well, just to make sure" and lunges forward, arms outstretched, pushing the joystick completely flat against the console hahaha.

[–] [email protected] 1 points 5 days ago (1 children)

Wait until you find out that probably wrong.

Its what we assumed for the last 100 odd years, but apparently in the last few we discovered they don't actually work like that.

[–] [email protected] 3 points 5 days ago (3 children)

oh, go on.

i haven't heard of the updated dynamics of flight.

[–] [email protected] 5 points 5 days ago (3 children)

This article does a pretty nice job of describing all the different theories

[–] [email protected] 3 points 5 days ago

I just want to tell the void that I arrived at a similar conclusion about induced high and low pressure zones based on the wing "slicing" the air in half as if it was a continuous material causing cavitation above the wing, and was mocked for it.

[–] [email protected] 2 points 5 days ago

thanks, that's a good article.

[–] [email protected] 1 points 5 days ago

That's a great article, thanks for the read.

[–] [email protected] 1 points 5 days ago (1 children)

I don't know why everybody focuses so much on the top of the wing. Relative to ambient air, the pressure above the wing is slightly reduced, but the pressure below the wing is massively increased. That massive increase is far more important than the slight reduction above.

We know this, because simple, flat airfoils are capable of flight. Think: paper airplanes, simple balsa models, etc.

The shape of the airfoil is not actually very important for lift. You can make a brick produce plenty enough lift to maintain its altitude, if you can provide sufficient thrust and control it's attitude.

The specific shape of the airfoil is primarily important for minimizing drag across a variety of speeds and angles of attack at various loadings. This is where the top surface of the wing becomes important. By maintaining the flow over the wing, drag is reduced, and controllability is maintained.

[–] [email protected] 1 points 5 days ago* (last edited 5 days ago)

yeah, I'm with you, the Newtonian makes more practical end complete sense to me sense to me as an explanation for a lift.

maybe the confusion comes from calling the motion of pushing air down "lift"

push-off.

hm. what the heck is an appropriate antonym for lift...

spring-hold.

oh, buoyancy?

maybe we should switch our talk from lift to buoyancy.

rather than generating lift, velocity through the air generates aerodynamic buoyancy due to the increase in downward pressure, or rather the compressed air beneath the airfoil.

[–] [email protected] -2 points 5 days ago (1 children)

I don't know the full story, only that the fact air particles have to speed up over the top so they match up at the end is incorrect - one at the top, one at the bottom don't actually arrive at the end at the same time. There is something missing.

[–] [email protected] 5 points 5 days ago (1 children)

This is wrong. Lift is generated from pressure difference. This pressure difference is caused by air moving faster over the top of the wing. I have no idea what you're talking about with air particles matching up at the end.

[–] [email protected] 1 points 5 days ago

I vaguely remember seeing a video that explained that how it's usually explained is wrong. That's what they're probably referring to. But it wasn't that we don't actually know how it works, just that the common simplification is not technically correct (which happens often with these things).