I always wondered how jet engine work. Maybe that is obviously

>>8057382
>why it rotates and air flow in one direction whet it press whit the same force in both?

Because engineers did like 500 different engines and then 1 actually worked and they have just spent the last hundred years making it better and better.

>>8057382
Work on your fucking prose, Pajeet.

>>8057382
This might help?
I can't tell what you're asking
https://youtube.com/watch?v=ueTGjegTKoo

>>8057392
It is not answer. I want to understand physic of processors. 'There are many very smart people that can do anything and no need to understand how" sounds like some kind of religion.

>>8057412
Thanks, that was interesting but is not an answer too.

>>8057382
The inlet of engine is spooled while the stages of the compressor begins to push air into the combustion chamber. The air and jet fuel mix, where by the mixture is combusted, the super heated by-products are vented out the back as a reactive force while pushing on the exhaust foils, which further spool the inlet compressors.

The blade fans vary in geometry between the stages, designed to considerations of minimizes turbulence, increasing airspeed through the stators and profile of the fan blade speeds given their angular velocity.

Given the critical nature of high speed, rotating parts, the fans are made of lightweight materials, and are thoroughly checked in quality before being installed.

You'd want to wait for a engineer to explain how work is conserved throughout. I tend to see it as a car, whereby the exhaust gases are mechanically linked to increase internal pressure.

>>8057453
It isn't when it should? Is that reason why?

Noob here, but after studying this

http://aerostudents.com/files/introductionToAerospaceEngineering/introductionToAerospaceEngineeringFullVersion.pdf

heres what I think.

First off, the parts of the propeller. It has a set of fans that each spin in their own opposite direction. This causes the air particles to slow down, because they are banging into so much shit, and with combination of new air particles entering in because the plane is moving, you get really compressed air, AKA, the air pressure is increased inside of the propeller. And higher air pressure just means more air molecules per a given distance, and here is where the otto and thrust equation come in.

A plane uses kerosene, which is gasoline with more carbon, and this causes more energy to release when a chemical reaction occurs. idk, i guess its because carbon has stronger bonds. But anyway, the otto equation is about how much mass of energy, or fuel, is given off by the engine when it burns. And, a high amount mass given off, means a higher thrust force (look at the equation). And the compressed air makes it so more mass is given off, resulting in more thrust in a given amount of time. Sorry, I need to study how engines work more.

Rip me apart /sci/

>>8057453
In car there is valves that control direction of air flow. Here just tube with fans. Direction of their rotation is depend on direction of air flow. Fan itself does not decide in what direction to rotate, and gas press in all directions with the same force. Then what decide direction if Aire flow?

There is many interesting information here but it seems like no one understands the question.

Centripedal force

>>8057382

The general idea is that you can get more energy by burning a higher concentration o ffuel and you can burn a higher concentration of fuel by making a higher concentration of oxygen via compressor stages.

The compressors work by voodoo fluid magic though.

https://www.grc.nasa.gov/www/k-12/airplane/caxial.html

>>8057502
I think I understand it a little more. Why the air flows in one direction? I will try to explain with pressure. Basically, highly concentrated pressure in one area, wants to go to an area with low pressure. The inside of the turbine is high pressure, so naturally, the air molecules would all go right towards the exist, where there is low air pressure; causing the air to flow in one direction.

??

>>8057518
Problem is that a turbine has two exits. Why it does not go in direction of compressor?

>>8057518
That's actually a pretty good question.

Basically there's a net lower pressure on the exit of the turbine than on incoming side. It seems like you basically keep stacking the air up "on itself" in several stages so you end up with high pressure make it one directional. Maybe you can think of it like a diode in that it's biased in such a way to push air through the turbine rather than out the front.

Shitty EE here with minimal knowledge of mechanical stuff, I won't claim I know what I'm talking about just how I see it.

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>>8057538
There are two factors for why.

First off, if a plane is moving, fast air molecules are constantly entering the turbine, so, the compressed air leaving through the exit, would basically be like driving on the wrong side of a highway.

What if its a stand still compressor in testing?

Bernoulli's law. Im guessing the fan blades are curved. Same way the wings of a plane, and a helicopter elevate. Its causing a suction, and once when that initial suction is going, the air is going to be going in one direction.

The only problem is, that I know a turbine is made up of multiple fans, so if one set of fans is going "forward" like in the picture, then im honestly kind of stuck.

>>8057551
That probably has a lot to do with the blade geometry

>>8057553
leaving through the entrance*

sorry, didn't mean to confuse you

>>8057553
but finally, judging by this pic. Im going to assume that all, if not the majority, of the fan blades are going "reverse", which causes a suction.

>>8057551
this explanation seems more fitting, because you mention a building layer, like the pressure gets compound with each set of blades.

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>>8057579
>pic
fuck, im terrible

>>8057551
>>8057553
>laughs at my propeller work as babby tier
>Cant even give a simple answer to how a jet engine works.
Never change /sci/.
you are way overcomplicating things the compressed air flows towards the combustion chamber because it is being pushed that way by the blades. Duh. And no fans go forward, all fans are on the same shaft that turns in one direction pulling air in. Between each fan there are what look like fans but are actually stationary blades that slow down the incoming air by deflection.

This thread illustrates all that is wrong with /sci/, eager to opine on topics that they have no clue about just to look smart. It is extremely obvious that you do not have the slightest fucking clue as to how an axial compressor works so why not jus not say anything or post a link to an explanation instead of making up shit on the fly?

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What a sorry thread

see webm >>8057382 for your answers

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>>8057704

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>Why turbine rotate compressor and not otherwise or in another words why it rotates and air flow in one direction whet it press whit the same force in both?
The answer to that is volume. Yes, the turbine does not have any greater of a pressure ratio to work with than the compressor does, but since the combustor increases the heat and volume of the fluid, the fluid does more work on the turbine than on the compressor (plenty enough to make up for any irreversibilities in the system, plus a good bit of surplus work to be used for driving a shaft or fan or just jet thrust through a nozzle).

>>8057382
A compressor is a machine that transfers energy to the fluid. A turbine gets energy from the fluid and converts it's thermal/kinetic energy into work that is transfered trough a shaft to the compressor. The jet engine is usually composed of a compressor (maybe two, a low pressure and a high pressure one) where the air is compressed, a combustion chamber where air and fuel are mixed and ignited to increase it's temperature. Now once the fluid is at a sufficiently high pressure and temperature it goes to the turbine (or the turbines, again high and low pressure). There it expands and it's energy is converted into work. The fluid further expands and is expelled through a nozzle where it's velocity is increased. Thus generating impulse.

I might have screwed up on a few details but that's kind of the way it works.

Look up the brayton cycle.

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>>8057382
The reason the engine doesn't turn into a hand grenade is because of mass flow. A turbine engine works off of the Brayton Cycle:
Intake (fan, ram air)
Compression (fan, compressor stages)
Combustion (combustion chamber)
Exhaust (turbines, jet pipe)

This is exactly the same in principle as the 4-stroke piston cycle, but there are 2 differences:
1. The Brayton Cycle is continuous
2. All 4 steps happen simultaneously

On a turbofan, the fan in front (N1) is connected to a shaft that is connected to one of the turbine stages, allowing it to rotate. It's job is to accelerate a large volume of air through a bypass, providing the majority of the thrust.

The compressor stages (low pressure and high pressure), connected to another couple turbines, increase the pressure of the gas through a series of compressor and stator blades. Typically, a shaft is connected to the HP compressor, which is used to power an accessory drive. Bleed air is also siphoned off of the compressor sections.

The combustion chamber (can, annular, or a combination) mixes air with jet fuel (similar to Kerosene) and ignites it. This adds energy to the gas, which is then forced by mass flow to the turbine, where the hot gas is run through a turbine.

The turbine is a disk of many blades connected to a shaft with the purpose of extracting the energy from the gas stream and transforming it into rotational energy, making the whole process perpetual.

After the gas passes through the turbine stages (HP, IP, LP), it is then forced out the exhaust, where it mixes with bypass and ambient air.

That is the basics of a turbofan engine