Wow found one of your early videos mate! Love the hairdo and the wooden framed whiteboard! Your confidence in presentation has grown massively since this vid, you're a natural now :) Keep up the good work
This is why teaching method hasn't changed in 200 years. I have seen many videos on jet engine working where they explain with animation but this one I understood the most. Thank you.
Only a small comment, the air velocity is quite constant through the compressor stages. The goal is to increase the pressure, not the speed. (To begin a preliminary design, you can start from the approximation that the inlet and outlet velocity of a given axial stage is constant) Thank you for posting, very good
That was awesome! Are you able to do a sequel video to this explaining how turbofan and turboprop engines work? If so, I'm sure we'd all love to see it!
BTW a turboshaft engine (the configuration explained later in the video, used in tanks and helicopters as explained) is being used in a street legal motorcycle! If you're interested it's called the Turbine Superbike, research it it's a pretty unique thing
Thank you very much I’m taking an Airframe and Power plant test tomorrow and i really couldn’t wrap my head around how it works. I really appreciate it
I'm not sure. I don't think so, but if the material was flexible I suppose it could, or if it were controlled somehow to increase/decrease the suction force. As far as I know though, I believe they are fixed.
I have just been in the Aviation Museum and watched all those jet engines. Thanks for your explanationts. It makes more sense now to me what I saw (and secretely moved some shafts - I couldn't resist - 🤫 without any harm of course ;) )
An afterburner introduces fuel into the exhaust stream and igniting it, producing more thrust as the gasses expand. This is where thrust vectoring and adjustable vanes come into their own in fighter aircraft as usually a computer like a FADEC would optimise the outlet vane diameter to produce maximum thrust with reheat. Hope this helps and sorry for long concentric replies.
Not sure about the overheating, it certainly creates more heat, but I'm not sure how much of it affects the aircraft. Fuel consumption goes way down though, for sure.
1. The compressor does NOT have turbine blades. Turbine is a device that converts kinetic energy into rotational shaft power. That's why you don't have turbine blades in the compressor but compressor blades. Terminology is important! 2. The air does NOT accelerate in the compressor. The narrowing of the compression path is meant to prevent the air from decelerating too much. 3. Modern engines don't have combustor cans anymore. They have a single annular combustor. 4. Modern aviation jet engines are turbofans that have a fan in front of the compressor. It accelerates air that bypasses the core jet engine that you drew completely and may create most of the thrust depending on the design. 5. It would be important to tell about the exhaust nozzle after the turbines which is what accelerates the gas to the highest speed producing thrust. Without the nozzle the gas coming out would be just a hot breath, exaggerating a bit.
I should correct myself a bit. The fan and compressor do in fact accelerate air from the relative standstill to the speeds inside the compressor. Also according to a Rolls Royce video the air is also accelerated between low pressure compressor (booster) and high pressure compressor. However the total air velocity does not increase while it's passing through either of the compressors.
rockhopper123452 Best thing to do is get a degree in aerospace engineering. Failing that, many books on thermo/fluid dynamics can help you. A good place to start is a book published by Rolls-Royce (in many editions) titled simply "The Jet Engine". I'd advise you to get the latest edition as it will reflect the most current information. It _is_ simplified to an extent and does not include the maths behind it (mostly), but that's what the degree and really thick and topic specific books are for :)
rockhopper123452 Sorry, I sent you a reply when you asked but it never registered obviously. I agree with 233kosta, just stay away from the latest Rolls Royce The Jet Engine book. It doesn't explain many things the older versions do and the quality is rubbish too. Two of my copies are falling apart by themselves! Also, check out this virtual tour by Rolls Royce with very good and easy to understand information: www.rolls-royce.com/interactive_games/journey03/ If you want a very comprehensive information package, still without complicated math, read the "Aircraft Gas Turbine Powerplants" published by Jeppesen.
I think I know what you mean. When the gases expand, they are going to move toward the path of least resistance. In the example above, because of the change in the pitch in the blades, the easiest path is out toward the rear of the engine. Though there is actually pressure on the backside of the compressor blades, there is more net force on the exhaust side that continues the momentum of the blades.
I know this is bringing a video back from the grave possibly but this seemed the best video to ask my question on. What are your thoughts on micro turbine hybrids as range extenders in both trucks and cars? maybe a video to explain the concept and the pros and cons from your point of view. P.S. Watching this old video of yours is a chuckle
@Aexotica Just like in cars, large turbines can have starter motors that rotate the main turbine to get things started (starts the rotation of the compressor). If it's a small engine, like for a model plane, you could even just put a fan up to it to get it started (or a hair dryer!).
Excellent explanation. I want to how the big fans at the front gets driven first? Is it that when the airplane runs faster in the run way, does the speed of the wind hitting these big fan spins compressing the air to start the combustion, is that correct?
You don't want to have on all the time because of the high fuel consumption. There are also limitations involving altitude and air pressure (i.e. it's much more efficient to activate an afterburner at certain conditions). I'm not sure of any overheating issues, but I assume the afterburner section experiences the similar conditions as the pre-turbine, combustion stage.
I was trying to understand jet engine easy theory last 6 years. .but you explain it very easy way. .thanks. .but can you tell me about shafts how it's joined with cover drum or whatever you call it. ..
Still have some many questions... shafts over shafts ? Combuster tubes ?? How is it attached to anything? What about reverse thrust ? How it speeds up when the plane or vehicle isn’t moving ? Clutches at all? Bearings ? So many more questions. Thanks for a Generic start though.
From the first time back in my childhood when I first heard about how jet engines work, quite until now I still can't understand, why the expanding gases don't exert the same momentum by braking the compressor as they accelerate the turbine. I mean, I know the thing works somehow, but the main trick (at least for me) remains always unexplained.
I read a book once and it suggested that the turbines and compressors were designed ie the angle of the blades in them, to facilitate the continued movement through the engine. path of least resistance. aswell as the combustion chamber outlets pointed at the turbines
You missed out the stators in the compressor stage I believe, its used to increase the pressure, as the axial flow coupled with the venturi effect of the engine design drops the pressure for increase in velocity.
Not quite. It is slaved off the main turbine, however depending on the engine design the N1 rotor can provide as much as 80% of the total output thrust in a high bypass engine, if that's what you were talking about when you mentioned commercial jet aircraft.
Large turbines can use bleed air from the APU to spool a small turbine which is geared with the compressors. When the main turbine spins fast enough, enough air is being compressed to the pressure where fuel can be introduced and combustion can start. After that, the engine is self-sustaining as long as it has fuel. Typically only used in large turbine engines. Others can use electric motors.
Having become a fan of Jason’s daylit videos of the past 5yrs or so(now 2022), this is quite a dramatic mood shift to go back and see. Jason, the actual drawing of the diagrams is more interesting than pointing to color dry erase drawings. lol Just sayin.
I believe the air flow through the engine stays at the same speed. Of course after the inlet duct slows it down and after the exhaust nozzle accelerates it. Also after the combustor the gas speed will be greater but the turbine does not slow the gases either. The compressor (Turbine) rotors and stator are designed to maintain a constant air speed.
nitpicking alert - type of engine described is a 3-spool, axial flow, turboshaft with cannular combustion chamber. - compressor wheels are not turbines - missing vital part, compressor stator blades which do the actual compression
Excellent explanation! But I had an ah ha moment half way through your video... Consider the engine in 3 pieces, 1st is the compressor, 2nd is the storage tank (this was my ah ha) the fuel is injected into the burner can (which remember, it's located inside the storage tank) sort of like direct injection in a car, and burned expanding the gases imparting more energy to the tank of air, the aft is the exhaust which is where the the burnt gases are expelled causing thrust and also turning the drive shaft to start the process all over again, except, the air never stops like my imaginary engine :-) When I thought of the engine as 3 distinct pieces, it all made since, now I had something that looked a lot like a normal 2 stroke engine.. Minus the stroke ;-) I realize you'll never see this, but I've studied turbine engines forever but never understood them, Thanks :-).
@EngineeringExplained thanks you. I have a follow-up if you don't mind: by what means or mechanism is fuel provided to be ignited, does it use fuel injection?
@Aexotica In fact, as he explained, they have starters. Most are pneumatic. Air flow from the Auxiliary Power Unit is used to spool up the engine to certain RPM where fuel can be injected thus ignited andd voila! the engine has started and now works on its own. the APU is another engine used mainly as backup to power all the aircraft electric, pneumatic, hidraulic systems when the main engines are shutt off or failed.
Important to note that for a turbine engine used to propel an airplane, only 15% of the air brought in through the front intake goes through the compressor and to the turbine, while the other 85% of the air goes around the outside the of the compressor through the bypass and is also compressed in a narrowing passageway as it gets squeezed out the back of the engine - as thrust.
Yeah, velocity would increase if the flow was incompressible, but the pressure causes density increase instead which satisfies the continuity equation of the flow.
Great example of Rolls Royce triple spool engine. Almost all if not all others only use 2 spools. GE P&W example. Now P&W has what they call a geared turbine/main fan blade. Just like you said, the main front fan runs most efficiently at lower speeds BUT turbines run better at higher speeds. So Instead of of a spool they use a highly efficient gearbox to drive the front main fan
It's midnight btw, I should be sleeping because I work in 7 hours but I really want to know how this Jet engine works. Thank you, youtube recommendation.
What is being talked about here is a "can-annular" combustion engine. There are various types of jet engines with different types of combustion sections (much like different car engines like a flat four vs a in-line 6). Most jet engines now a days consist of an Annular Combustor (like a donut instead of being lined with cans). The engine sections consist of a Fan section (intake), Compressor section, Combustor section, and a two stage Turbine section (exhaust section). These typically consist of a 2 stage drive shaft instead of a 3 stage (which is shown in this video). The Fan, which typically has 3 blade rotor stages, introduces air into your compressor section, which typically has 5-7 blade rotor stages. Squeezes the compressed air into your combustor section where fuel is added via spray nozzles. Your spray nozzles have air swirlers which allow for evenly mixed fuel to air ratios where it is then ignited via ignitor plugs (larger spark plugs basically). The flames then pass through your two part Turbine section, High Pressure Turbine (HPT) and Low Pressure Turbine (LPT). The Fan and LPT are linked via your fan drive shaft and spin at the same RPM, the same is true for your Compressor and HPT. The exhaust gases from the combustor power the HPT which sends hot gases aft to the LPT. The LPT (which is linked via the fan) in turn powers the Fan sucking air in which powers the compressor. That is your basic jet engine.
yep.. but for example in fighter jets they don't you use afterburner that much only on take off, vertical flight or dog fight etc.. whats the disadvantage of afterburners.. is it only worst fuel consumption or it creates overheating after a while in engine?
I believe that the first intake blades that are connected to the second shaft to a slower turbine are a lot larger and called fan blades which creates the majority of the thrust not into the engine but around the engine. These are called bypass fan blades because they bypass the engine and blow large volumes of slower air around the engine. The pure turbine engine that you are talking about does not need slower fan blades. A straight turbo jet engine has only one shaft. Unless of course you can give me the name of a turbo jet engine that has two shafts. the reason a fan jet needs two shafts is because bypass fan blades move such a great volume of air that if it were attached to the main engine there would be a compressor stall and stop the engine . There used to be turbo fan jet engines where everything was driven on one shaft but the fans were a lot smaller and could run faster. but you But you are right about the extra turbine if the engine is used to drive external devices,
The very basic is same as any piston engine. Suck, squeeze, bang and blow. Except the piston engine extract the power after the bang and transferring all the power to the crankshaft. The jet wait a little longer and extract the power from the blow. There are also some variation as to when and where the fuel are introduced for the bang. Direct injection piston engines are similar to jets but jets is the only kind that have another bang after "blow" (afterburner or as the Limeys said Reheat.)
APU or Auxiliary Power Unit. Its a machine that uses electricity from the generators to create a spinning motion from the turbine. Once the combustion starts the APU shuts off.
@EngineeringExplained FYI: the Rolls-Royce RB211 is a triple spool coaxe engine. It may be the only aviation one in the world. I don't have my Encyclopedia of Turbine Engines in front of me so I can't say for sure. Babysitting at a beer buddy's house.
hi, im curious if jet engines use spark plugs to ignite the air fuel mixture or is it just that the air is too hot that ignites by itself when mixed with fuel
Literally the clearest explanation I could find and it's like 6 years old. Thanks!
Haha very welcome!
they all use fansy animations but no one provides good clear info like this guy
Lol 😂
9 years now
11 years now and still the simplest way to set your mind to understand the complexity of a jet engine.
Unfortunately I stick to automotive based videos now. Cheers
Sam Aj indeed, make a suggestion on social media.
I’m subscribed for a few years but Never knew of this video until i wanted to find out how jet engines work lol.
Wasn't the easiest to follow in the beginning, but I'm very happy that I watched it through - this was the best explanation I've had so far. Thanks!
wow this was the best explanation i could find, even though it is 18 years old! Thank you for saving my school project!
This video is so clear! You are a great teacher! I'm a pilot, preparing for initial training on a jet.
Wow found one of your early videos mate! Love the hairdo and the wooden framed whiteboard!
Your confidence in presentation has grown massively since this vid, you're a natural now :)
Keep up the good work
This is why teaching method hasn't changed in 200 years. I have seen many videos on jet engine working where they explain with animation but this one I understood the most. Thank you.
This dude... Is not the hero we deserved, but the hero we needed
These whiteboards should be framed for how easy they are able to summarize and make understandable very complicated subjects..
Wow engineering explained 9 yrs ago love this guy even now.
I want this guy as my Physics lecturer..
Out of all the super well put together 3D videos you are the only one I could understand. Simple and directed. Great for visual learners. Thank you.
Only a small comment, the air velocity is quite constant through the compressor stages. The goal is to increase the pressure, not the speed. (To begin a preliminary design, you can start from the approximation that the inlet and outlet velocity of a given axial stage is constant)
Thank you for posting, very good
Might I suggest adding also a separate set of videos on how axial compressors and turbines work, I think they would supplement this video nicely
Great explanation! at last, a straight forward, no fancy CGI, thx.
I'm stunned it took you 6 minutes to explain me something i have been trying to figure out for years watching several other video's about Thanks a lot
I am so using your video's for my Aviation Students.
That was awesome! Are you able to do a sequel video to this explaining how turbofan and turboprop engines work? If so, I'm sure we'd all love to see it!
@Aexotica Yes, the fuel is sent into the combustor via fuel injectors.
Holy crap, you've come a long way since then !!!
but your explanations are always great !
BTW a turboshaft engine (the configuration explained later in the video, used in tanks and helicopters as explained) is being used in a street legal motorcycle! If you're interested it's called the Turbine Superbike, research it it's a pretty unique thing
Thank you very much I’m taking an Airframe and Power plant test tomorrow and i really couldn’t wrap my head around how it works. I really appreciate it
I have listen to this topic several times, this is simple enough to almost anyone. thanks
Getting recommended this in 2022. Great explanation!
I'm not sure. I don't think so, but if the material was flexible I suppose it could, or if it were controlled somehow to increase/decrease the suction force. As far as I know though, I believe they are fixed.
I love your work and really appreciate your knowledge and effort to do this stuff. Thanks, man!
I searched lots of videos at UA-cam but this video finally answered my queries. Thank you.
I have just been in the Aviation Museum and watched all those jet engines. Thanks for your explanationts. It makes more sense now to me what I saw (and secretely moved some shafts - I couldn't resist - 🤫 without any harm of course ;) )
An afterburner introduces fuel into the exhaust stream and igniting it, producing more thrust as the gasses expand. This is where thrust vectoring and adjustable vanes come into their own in fighter aircraft as usually a computer like a FADEC would optimise the outlet vane diameter to produce maximum thrust with reheat. Hope this helps and sorry for long concentric replies.
This is the best Explanation ever.
Not sure about the overheating, it certainly creates more heat, but I'm not sure how much of it affects the aircraft. Fuel consumption goes way down though, for sure.
I start school on aviation maintenance next month. I can't wait to learn even more.
Cool. I'm thinking about the same career path. Not sure yet though.
Man, it's pretty cool stuff. I'm learning basic electricity right now
Cool. Some of branches of aerospace and marine look really cool but I still have no idea what I wanna do.
You should have them give you a tour of the schools.
Perhaps
1. The compressor does NOT have turbine blades. Turbine is a device that converts kinetic energy into rotational shaft power. That's why you don't have turbine blades in the compressor but compressor blades. Terminology is important!
2. The air does NOT accelerate in the compressor. The narrowing of the compression path is meant to prevent the air from decelerating too much.
3. Modern engines don't have combustor cans anymore. They have a single annular combustor.
4. Modern aviation jet engines are turbofans that have a fan in front of the compressor. It accelerates air that bypasses the core jet engine that you drew completely and may create most of the thrust depending on the design.
5. It would be important to tell about the exhaust nozzle after the turbines which is what accelerates the gas to the highest speed producing thrust. Without the nozzle the gas coming out would be just a hot breath, exaggerating a bit.
I should correct myself a bit. The fan and compressor do in fact accelerate air from the relative standstill to the speeds inside the compressor. Also according to a Rolls Royce video the air is also accelerated between low pressure compressor (booster) and high pressure compressor. However the total air velocity does not increase while it's passing through either of the compressors.
veeaa Where can i learn more about jet engines? Im actually really interested.
rockhopper123452
Best thing to do is get a degree in aerospace engineering. Failing that, many books on thermo/fluid dynamics can help you.
A good place to start is a book published by Rolls-Royce (in many editions) titled simply "The Jet Engine". I'd advise you to get the latest edition as it will reflect the most current information. It _is_ simplified to an extent and does not include the maths behind it (mostly), but that's what the degree and really thick and topic specific books are for :)
rockhopper123452 Sorry, I sent you a reply when you asked but it never registered obviously. I agree with 233kosta, just stay away from the latest Rolls Royce The Jet Engine book. It doesn't explain many things the older versions do and the quality is rubbish too. Two of my copies are falling apart by themselves!
Also, check out this virtual tour by Rolls Royce with very good and easy to understand information:
www.rolls-royce.com/interactive_games/journey03/
If you want a very comprehensive information package, still without complicated math, read the "Aircraft Gas Turbine Powerplants" published by Jeppesen.
veeaa
Have they messed it up in the latest release? Damn
Dude ...it's 2020....look at you now....thumbs up
Thank you, much better than the other explanations of this on UA-cam
10 years later you’ve come a long way Jason.
Not sure about the pitch, it could be equal with the speeds of the following props increasing, or it could be as you've described, or a mix of both.
I think I know what you mean. When the gases expand, they are going to move toward the path of least resistance. In the example above, because of the change in the pitch in the blades, the easiest path is out toward the rear of the engine. Though there is actually pressure on the backside of the compressor blades, there is more net force on the exhaust side that continues the momentum of the blades.
this is the best explanation i could find!
wow, i am newbie , and i see this is very clear explanation, and simple. SUBSCRIBED!
I know this is bringing a video back from the grave possibly but this seemed the best video to ask my question on. What are your thoughts on micro turbine hybrids as range extenders in both trucks and cars? maybe a video to explain the concept and the pros and cons from your point of view.
P.S. Watching this old video of yours is a chuckle
@Aexotica Just like in cars, large turbines can have starter motors that rotate the main turbine to get things started (starts the rotation of the compressor). If it's a small engine, like for a model plane, you could even just put a fan up to it to get it started (or a hair dryer!).
Excellent explanation. I want to how the big fans at the front gets driven first? Is it that when the airplane runs faster in the run way, does the speed of the wind hitting these big fan spins compressing the air to start the combustion, is that correct?
@TheTerribleSwede No, just using it as a demonstration to show how the different stages of the compressor rotate at different speeds.
WOW!!! you been doing this since 2011?? i just learned about you 3 yrs ago!!
You don't want to have on all the time because of the high fuel consumption. There are also limitations involving altitude and air pressure (i.e. it's much more efficient to activate an afterburner at certain conditions). I'm not sure of any overheating issues, but I assume the afterburner section experiences the similar conditions as the pre-turbine, combustion stage.
+Engineering Explained can you please make an updated video ?
@TheTerribleSwede Well, I'm no expert on turbine engines. Thanks for the tip; I made this video for a student who wanted help on a project.
I was trying to understand jet engine easy theory last 6 years. .but you explain it very easy way. .thanks. .but can you tell me about shafts how it's joined with cover drum or whatever you call it. ..
Simple but very nice and clear explanations. Thanks!
Still have some many questions... shafts over shafts ? Combuster tubes ?? How is it attached to anything? What about reverse thrust ? How it speeds up when the plane or vehicle isn’t moving ? Clutches at all? Bearings ? So many more questions. Thanks for a Generic start though.
Subscribed for the car content many years ago, but back watching this old video because I'm in ground school now trying to become a pilot 😁😁
Likely some arms that reach across and hold it on bearings.
From the first time back in my childhood when I first heard about how jet engines work, quite until now I still can't understand, why the expanding gases don't exert the same momentum by braking the compressor as they accelerate the turbine. I mean, I know the thing works somehow, but the main trick (at least for me) remains always unexplained.
No one really knows how Jet Engines work it’s all Magic!
I've just watched a video actually and now I know how they work.
@@jibjob3298 yeah it's not that simple unless you're a aeronautics graduate UA-cam doesn't provide you the full picture but only the basics
I read a book once and it suggested that the turbines and compressors were designed ie the angle of the blades in them, to facilitate the continued movement through the engine. path of least resistance. aswell as the combustion chamber outlets pointed at the turbines
You missed out the stators in the compressor stage I believe, its used to increase the pressure, as the axial flow coupled with the venturi effect of the engine design drops the pressure for increase in velocity.
Outstanding. Thanks for this explanation!
Not quite. It is slaved off the main turbine, however depending on the engine design the N1 rotor can provide as much as 80% of the total output thrust in a high bypass engine, if that's what you were talking about when you mentioned commercial jet aircraft.
I see the whiteboard has been with us from the very early beginning.
Large turbines can use bleed air from the APU to spool a small turbine which is geared with the compressors. When the main turbine spins fast enough, enough air is being compressed to the pressure where fuel can be introduced and combustion can start. After that, the engine is self-sustaining as long as it has fuel. Typically only used in large turbine engines. Others can use electric motors.
Having become a fan of Jason’s daylit videos of the past 5yrs or so(now 2022), this is quite a dramatic mood shift to go back and see.
Jason, the actual drawing of the diagrams is more interesting than pointing to color dry erase drawings. lol
Just sayin.
I believe the air flow through the engine stays at the same speed. Of course after the inlet duct slows it down and after the exhaust nozzle accelerates it. Also after the combustor the gas speed will be greater but the turbine does not slow the gases either. The compressor (Turbine) rotors and stator are designed to maintain a constant air speed.
You legend, stumbled across this video, but I’ve been watching all your videos on cars for years, look how far you’ve come mate!
Great explanation. Thank you. My 9 year old understands it. Using the drawing and the main components as a science project.
Great explanations and easy to understand.
nitpicking alert
- type of engine described is a 3-spool, axial flow, turboshaft with cannular combustion chamber.
- compressor wheels are not turbines
- missing vital part, compressor stator blades which do the actual compression
He does a great job explaining this stuff.
12 years old and still, Thanks!
your the first one who doesnt just say what the parts are, but also tells what they do
Such a good explanation
The clearest explanation out there.
Excellent explanation! But I had an ah ha moment half way through your video... Consider the engine in 3 pieces, 1st is the compressor, 2nd is the storage tank (this was my ah ha) the fuel is injected into the burner can (which remember, it's located inside the storage tank) sort of like direct injection in a car, and burned expanding the gases imparting more energy to the tank of air, the aft is the exhaust which is where the the burnt gases are expelled causing thrust and also turning the drive shaft to start the process all over again, except, the air never stops like my imaginary engine :-) When I thought of the engine as 3 distinct pieces, it all made since, now I had something that looked a lot like a normal 2 stroke engine.. Minus the stroke ;-) I realize you'll never see this, but I've studied turbine engines forever but never understood them, Thanks :-).
Thx UA-cam algorithm! Personally a never before seen video.
@EngineeringExplained thanks you. I have a follow-up if you don't mind: by what means or mechanism is fuel provided to be ignited, does it use fuel injection?
Easier to understand than the videos with fancy graphics and robotic narration. Thanks!
Nicely made man!
@Aexotica In fact, as he explained, they have starters. Most are pneumatic. Air flow from the Auxiliary Power Unit is used to spool up the engine to certain RPM where fuel can be injected thus ignited andd voila! the engine has started and now works on its own. the APU is another engine used mainly as backup to power all the aircraft electric, pneumatic, hidraulic systems when the main engines are shutt off or failed.
Important to note that for a turbine engine used to propel an airplane, only 15% of the air brought in through the front intake goes through the compressor and to the turbine, while the other 85% of the air goes around the outside the of the compressor through the bypass and is also compressed in a narrowing passageway as it gets squeezed out the back of the engine - as thrust.
The velocity of air doesn’t increase as it enter through the compressors, it actually decreases because the pressure is increasing in that time.
Your totally right. The compressor increases the static pressure. And the temperature raises. But the airspeed in the compressor is constant.
Yeah, velocity would increase if the flow was incompressible, but the pressure causes density increase instead which satisfies the continuity equation of the flow.
Great example of Rolls Royce triple spool engine. Almost all if not all others only use 2 spools. GE P&W example. Now P&W has what they call a geared turbine/main fan blade. Just like you said, the main front fan runs most efficiently at lower speeds BUT turbines run better at higher speeds. So Instead of of a spool they use a highly efficient gearbox to drive the front main fan
It's midnight btw, I should be sleeping because I work in 7 hours but I really want to know how this Jet engine works. Thank you, youtube recommendation.
What is being talked about here is a "can-annular" combustion engine. There are various types of jet engines with different types of combustion sections (much like different car engines like a flat four vs a in-line 6). Most jet engines now a days consist of an Annular Combustor (like a donut instead of being lined with cans). The engine sections consist of a Fan section (intake), Compressor section, Combustor section, and a two stage Turbine section (exhaust section). These typically consist of a 2 stage drive shaft instead of a 3 stage (which is shown in this video). The Fan, which typically has 3 blade rotor stages, introduces air into your compressor section, which typically has 5-7 blade rotor stages. Squeezes the compressed air into your combustor section where fuel is added via spray nozzles. Your spray nozzles have air swirlers which allow for evenly mixed fuel to air ratios where it is then ignited via ignitor plugs (larger spark plugs basically). The flames then pass through your two part Turbine section, High Pressure Turbine (HPT) and Low Pressure Turbine (LPT). The Fan and LPT are linked via your fan drive shaft and spin at the same RPM, the same is true for your Compressor and HPT. The exhaust gases from the combustor power the HPT which sends hot gases aft to the LPT. The LPT (which is linked via the fan) in turn powers the Fan sucking air in which powers the compressor. That is your basic jet engine.
Indeed, Hans von Ohain used an annular combustion in the worlds first jet engine.
Clever explanation .
yep.. but for example in fighter jets they don't you use afterburner that much only on take off, vertical flight or dog fight etc.. whats the disadvantage of afterburners.. is it only worst fuel consumption or it creates overheating after a while in engine?
I believe that the first intake blades that are connected to the second shaft to a slower turbine are a lot larger and called fan blades which creates the majority of the thrust not into the engine but around the engine. These are called bypass fan blades because they bypass the engine and blow large volumes of slower air around the engine. The pure turbine engine that you are talking about does not need slower fan blades. A straight turbo jet engine has only one shaft. Unless of course you can give me the name of a turbo jet engine that has two shafts. the reason a fan jet needs two shafts is because bypass fan blades move such a great volume of air that if it were attached to the main engine there would be a compressor stall and stop the engine . There used to be turbo fan jet engines where everything was driven on one shaft but the fans were a lot smaller and could run faster. but you But you are right about the extra turbine if the engine is used to drive external devices,
Front of the intake is the compressor blades not turbine blades as you have called them at the beginning
very good explanation
Very well explained. There is also a diagram on the NASA website.
Afterburners incorporate a method of injecting fuel into the exhaust of a jet engine, burning up the remaining oxygen and creating extra thrust.
The very basic is same as any piston engine. Suck, squeeze, bang and blow. Except the piston engine extract the power after the bang and transferring all the power to the crankshaft. The jet wait a little longer and extract the power from the blow. There are also some variation as to when and where the fuel are introduced for the bang. Direct injection piston engines are similar to jets but jets is the only kind that have another bang after "blow" (afterburner or as the Limeys said Reheat.)
APU or Auxiliary Power Unit. Its a machine that uses electricity from the generators to create a spinning motion from the turbine. Once the combustion starts the APU shuts off.
Very good video. Thank you so much!
very good; clear explanation!
Very good!! You did explain the basic. Oh yeah, don't forget the stators ^^.
Great explanation!
Best... i think we all here need more related sequential videos up to a working prototype.
@EngineeringExplained FYI: the Rolls-Royce RB211 is a triple spool coaxe engine. It may be the only aviation one in the world. I don't have my Encyclopedia of Turbine Engines in front of me so I can't say for sure. Babysitting at a beer buddy's house.
hi, im curious if jet engines use spark plugs to ignite the air fuel mixture or is it just that the air is too hot that ignites by itself when mixed with fuel
why does the pressure inside the combustion chamber not push against the compressed air and slowing down the compressor to a stand still?