Re: Do rockets push off the air?
« Reply #60 on: December 08, 2023, 02:42:06 PM »
Whilst I echo Dr V-N's sentiments (and call me Mr Cynical) I am curious to what extent A80's nephew is on-board with this idea.  ("My uncle said what"?).  I mean, can we get an outline of how the conversation went?  Did you come up with the theory, or did you get it from  him?  When did you last discuss it?  After all, we only have your assertion that he is in agreement. 

As for General Electric and Pratt & Whitney being on the same page, without any references, this adds a whole 'nother stage of incredulity. 

Offline Action80

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Re: Do rockets push off the air?
« Reply #61 on: December 08, 2023, 05:13:20 PM »
You and your nephew have some pretty big balls to stand up in public and say that Newton's 3rd law of physics isn't real. I'm sure you must have some amazing proof that will blow away centuries of science. Do you have any evidence that doesn't come from your own mind or from YouTube?
You have no balls to stand up say that I have denied the third law of Newton. Equal and opposite reaction. Gas goes out one way, and the rocket or jet travels the other.

I am sure the only proof you have ever come up with in your life has some sort of warning label affixed to it warning about use during pregancy.
To be honest I am getting pretty bored of this place.

Offline Action80

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Re: Do rockets push off the air?
« Reply #62 on: December 08, 2023, 05:21:27 PM »


So, all internal...

And yet all the arrows in Figure 1-1 show the exhaust traveling to to the rear.

If it truly was all internal, then the thrust would be traveling to the front, like some other jokers like to claim here.



Got the correction; thanks.  This is a simplified diagram of the gas flow through the engine; it does not illustrate thrust.
Ah, yes...the good ole "ignore what your lying fucking eyes are looking at!" argument.
It shows air being inducted from the left, compressed and impelled centrifugally by the compressor, diffused and entering the combustion chamber (to the right), passing though the turbine and exiting (to the right).  (Incidentally, the fact that the intake is to the left is just a convenience.  Many engines draw their air from all around, it doesn't matter.  The only important vector is that exhaust goes right, reactive thrust goes left).
Exhaust gas generates the thrust, period. No exhaust gas, no thrust. Exhaust gas generates a plume.
It is a simplified diagram is explaining the gas path.  To the target audience, the fact that thrust acts to the left does not require explanation.  Why would any of the arrows point left?

Because if you read the posts of the asshat train of various posters here, they are gaslighting the shit out of the issue, claiming the exhaust gas is pushing somewhere to the front of the rocket within the combustion chamber, quite similar to what you are trying to now claim happens with gas turbine engines.
 

An equivalent diagram for a road vehicle might show the engine, pistons, transmission and wheels going round.  The fact that the wheels try to push the road backwards does not need to be explained.
Nobody gives a damn about your fake analogies and comparisons.
To be honest I am getting pretty bored of this place.

Re: Do rockets push off the air?
« Reply #63 on: December 08, 2023, 05:25:58 PM »
You’re holding onto someone in a vacuum.
You push off each other. According to Action80, only one of you should move (the gas should move but not the rocket).
After all, before you both push you’re a “closed system”. It’s almost as if, when you push off the other person, the le momentum is… le conserved.

Rockets are, in fact, observed to gain efficiency at higher altitudes with less air resistance (varying slightly with the engine’s specified job)
« Last Edit: December 08, 2023, 05:28:59 PM by Realestfake »

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Offline RonJ

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Re: Do rockets push off the air?
« Reply #64 on: December 08, 2023, 06:09:57 PM »
General Electric gas turbine engines work on all the normal principles of physics you are taught in college engineering school.  I don’t need to consult with a relative of any kind as I am, personally, a federally certified gas turbine engineer.  There are some gas turbine powered, government owned, military ships in service that I have personally worked aboard many times.   A gas will always flow from a higher pressure towards a lower pressure.  Figure 1-2 on page 2 would be a more relevant diagram illustrating how a gas turbine works.  The compressor blades are spinning, and this accelerates the air.  This air mass acceleration is a source of the turbine engine’s forward thrust.  Where does the compressor get its power to accelerate the air?  You can see it’s via the shaft connecting the compressor with the turbine.  The turbine is powered by the released energy of the burning fuel inside the combustion chamber that is then routed past the turbine blades to provide power to the turbine/compressor shaft.  The exhaust from this operation is then expelled through the propelling nozzle.  The nozzle will provide a little more forward force because the exhaust gases are accelerated when passing through the nozzle.  The net force will be in a direction opposite the incoming air flow.   


These gas turbine engines will require atmospheric oxygen for fuel combustion where rocket engines do not.  The rockets carry their own oxygen with them inside.  Both rockets and turbines provide forward thrust in the same manner, however.  Both rely on accelerating mass to provide an equal and opposite force.  Newton’s law never specifies what the mass must be.  In a turbine engine, it’s outside air and combustion products.  On a rocket its all combustion products.  On a ship or a boat water is accelerated by the propellor to provide forward thrust. 
You can lead flat earthers to the curve but you can't make them think!

Offline Action80

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Re: Do rockets push off the air?
« Reply #65 on: December 08, 2023, 06:52:42 PM »
You’re holding onto someone in a vacuum.
You push off each other. According to Action80, only one of you should move (the gas should move but not the rocket).[
Two people pushing off each other is actually a force pair. You are almost getting it.
After all, before you both push you’re a “closed system”. It’s almost as if, when you push off the other person, the le momentum is… le conserved.
Trying to equate two people pushing off each other to the operation of a rocket is just plain stupid, so do everyone a favor and stop posting bs.

Rockets are, in fact, observed to gain efficiency at higher altitudes with less air resistance (varying slightly with the engine’s specified job)
No shit. You have any other obvious tidbits of drivel to add to your own op?

Rocket engines can certainly operate at higher altitudes than jets, but that is only because they carry their own oxidizers and require no air intake to accomplish combustion. Once external environment pressure drops below a certain level (i.e., pressures reported at or below the supposed "outer space"), rockets can no longer achieve propulsion due to a lack of a force pair.
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Offline RonJ

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Re: Do rockets push off the air?
« Reply #66 on: December 08, 2023, 07:27:15 PM »
Inside a rocket's combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.   
You can lead flat earthers to the curve but you can't make them think!

Re: Do rockets push off the air?
« Reply #67 on: December 08, 2023, 07:30:54 PM »
Inside a combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.

This is correct.


Trying to equate two people pushing off each other to the operation of a rocket is just plain stupid, so do everyone a favor and stop posting bs.
Do explain  :) a person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force.
« Last Edit: December 08, 2023, 07:34:36 PM by Realestfake »

Offline Action80

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Re: Do rockets push off the air?
« Reply #68 on: December 08, 2023, 07:36:20 PM »
Inside a rocket's combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.
You have absolutely no idea what you are writing. Gas released to vacuum performs 0 work. It freely expands.

Joule's Law.
To be honest I am getting pretty bored of this place.

Offline Action80

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Re: Do rockets push off the air?
« Reply #69 on: December 08, 2023, 07:40:02 PM »
Inside a combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.

This is correct.

This in incorrect. Gas released to a vacuum performs 0 work.

Joule's Law.


Trying to equate two people pushing off each other to the operation of a rocket is just plain stupid, so do everyone a favor and stop posting bs.
Do explain  :) a person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force.
You are clearly stating the gas exhaust (something which is part of the rocket, a single closed system, as something entirely separate, like the other person.

It is foolish and you are writing crapola.

Look, I don't care how many screwed-up alts you want to recruit to chime in.

As long as your alive and post crap like tyou are posting now, you will remain wrong.
« Last Edit: December 08, 2023, 07:42:20 PM by Action80 »
To be honest I am getting pretty bored of this place.

Re: Do rockets push off the air?
« Reply #70 on: December 08, 2023, 07:41:12 PM »
You have absolutely no idea what you are writing. Gas released to vacuum performs 0 work. It freely expands.

Joule's Law.

That is literally not what Joule’s Law is. Joule’s Law is about the proportionality of heat generated and current through a conductor. I think we’re about wrapped up here.

Re: Do rockets push off the air?
« Reply #71 on: December 08, 2023, 07:44:34 PM »
You are clearly stating the gas exhaust (something which is part of the rocket, a single closed system, as something entirely separate, like the other person.

It is foolish and you are writing crapola.

You are objectively wrong. Two people attached to each other is a closed system in the same way gas inside a fuel tank is.

A person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force. And neither examples have anything to do with atmosphere.
« Last Edit: December 08, 2023, 07:47:02 PM by Realestfake »

Offline Action80

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Re: Do rockets push off the air?
« Reply #72 on: December 08, 2023, 07:46:49 PM »
You have absolutely no idea what you are writing. Gas released to vacuum performs 0 work. It freely expands.

Joule's Law.

That is literally not what Joule’s Law is. Joule’s Law is about the proportionality of heat generated and current through a conductor. I think we’re about wrapped up here.
Joule's expansion.

It is about gas freely expanding when it is released to a vacuum.

Forms no plume.

You are wrapped alright. Probably in a straight jacket or something.

To be honest I am getting pretty bored of this place.

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Offline RonJ

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Re: Do rockets push off the air?
« Reply #73 on: December 08, 2023, 07:48:23 PM »
Yes, the gas would freely expand once it was outside of the rocket engine.   At that point the exhaust gas mass would have already been accelerated and an equal and opposite force would be applied to the forward end of the combustion chamber.  The fuel is not being burned in a vacuum but inside the combustion chamber enclosure.  A rocket would be more efficient if the gas was dispersed immediately once it exited the rocket.  The action – reaction part would already be completed. 
You can lead flat earthers to the curve but you can't make them think!

Re: Do rockets push off the air?
« Reply #74 on: December 08, 2023, 07:49:37 PM »
Joule's expansion.

It is about gas freely expanding when it is released to a vacuum.

Sorry, but Joule (not Joule’s) expansion is not the same thing as Joule’s Law. Gases expanding in space has nothing to do with the reaction force of the combustion moving the rocket.
« Last Edit: December 08, 2023, 07:52:08 PM by Realestfake »

Offline Action80

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Re: Do rockets push off the air?
« Reply #75 on: December 08, 2023, 07:52:04 PM »
You are clearly stating the gas exhaust (something which is part of the rocket, a single closed system, as something entirely separate, like the other person.

It is foolish and you are writing crapola.

You are objectively wrong. Two people attached to each other is a closed system in the same way gas inside a fuel tank is.
Trying to claim a pair of people are a single unit...FUCKING HILARIOUS!!!

Tell you what, Copernicus...

Draw a goddamn diagram of a pair of people acting as a single closed system, while at the same fucking time pushing off each other so they can go opposite directions, and submit the diagram for critique to a science professor.

Once he okays that piece of crap, then post it here with the verification and I'll concede, okay?

A person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force.
Just more crap that is so goddamn wrong it boggles the mind.

You are truly a piece of work.
To be honest I am getting pretty bored of this place.

Offline Action80

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Re: Do rockets push off the air?
« Reply #76 on: December 08, 2023, 07:54:51 PM »
Joule's expansion.

It is about gas freely expanding when it is released to a vacuum.

Sorry, but Joule (not Joule’s) expansion is not the same thing as Joule’s Law. Gases expanding in space has nothing to do with the reaction force of the combustion moving the rocket.
Yeah, Joule has more than one.

Gas, when released to vacuum, performs 0 work.

It is a law of physics.

It is named after Joule.

Ergo, Joule's Law.

It is the product of the combustion that moves the rocket, you dyngus.
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Offline markjo

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Re: Do rockets push off the air?
« Reply #77 on: December 09, 2023, 01:26:30 AM »
The exhausted gas is part of the rocket. A rocket is a closed system.
If you want to consider a rocket to be a closed system, then you must not ignore conservation of momentum.  If the exhaust is being accelerated one way, then the rest of the rocket must be accelerated the opposite way in order for momentum to be conserved.  That is, unless you think that accelerating rocket exhaust doesn't exhibit momentum.


Gas, when released to vacuum, performs 0 work.
True, but irrelevant.  All of the relevant work is done inside the rocket engine, before the exhaust is released into the vacuum.
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Offline RonJ

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Re: Do rockets push off the air?
« Reply #78 on: December 09, 2023, 01:54:58 AM »
Imagine some fuel inside a rocket. That fuel has some mass.  The fuel and the rocket have about the same relative velocity.  Now some fuel is inducted into the combustion chamber and combustion starts and the fuel’s energy is released.  The combustion chamber is closed at one end and open at the exhaust end.  Pressure inside the combustion chamber builds up due to the energy released by burning the fuel.   The combusted fuel’s mass is ejected at an accelerated rate out the exhaust end.  Newton’s law would say the accelerated fuel mass would produce an equal and opposite reaction.  That opposite force vector would be in the general direction of the nose of the rocket.


Here is your ‘force pair’.  The mass of the combusted rocket fuel being accelerated toward the exhaust port at the rear of the rocket and the forward part of the combustion chamber attached to the rocket itself.  The rocket’s mass is being accelerated in one direction and the mass of the accelerated fuel in the opposite direction.  The dividing line is the forward part of the combustion chamber as it divides the accelerating mass of the rocket itself in one direction with the accelerating mass of the combusted fuel in the opposite direction.


Any external air pressure at the exhaust end acts like a small back pressure that will slow down the acceleration rate of the exiting combusted fuel a little and reduce the forward acceleration rate of the rocket.  If the rocket is in a vacuum that back pressure will be close to zero and the burned fuel mass will be accelerated at a greater rate.  Everything takes place inside the rocket and the lack of external air has nothing to do with the fuel being accelerated in one direction and the rocket being accelerated in the opposite direction. 
« Last Edit: December 09, 2023, 01:58:26 AM by RonJ »
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Offline Action80

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Re: Do rockets push off the air?
« Reply #79 on: December 09, 2023, 09:50:40 AM »
The exhausted gas is part of the rocket. A rocket is a closed system.
If you want to consider a rocket to be a closed system, then you must not ignore conservation of momentum.  If the exhaust is being accelerated one way, then the rest of the rocket must be accelerated the opposite way in order for momentum to be conserved.  That is, unless you think that accelerating rocket exhaust doesn't exhibit momentum.
A rocket is a closed system. I haven't ignored the conservation of momentum. You might want to read the thread before making any more lying comments.

Gas, when released to vacuum, performs 0 work.
True.
Fixed that for you.
All of the relevant work is done inside the rocket engine, before the exhaust is released into the vacuum.
Another cosigner to the foolish idea. You are probably the originator of this heaping pile of crap you are writing here in this thread. Just what is the "relevant work " of a rocket?

It is the exhaust plume (i.e., mass ejected, at an accelerated rate) going in one direction causing the rocket or jet to go in the opposite direction.

Do you wish to continue to display your lies and/or ignorance to the audience, penguin?
« Last Edit: December 09, 2023, 01:32:04 PM by Action80 »
To be honest I am getting pretty bored of this place.