@DemonZapan I think the electronic starter motor doubles as a generator in flight (all DC motors can double as generators). However, this motor is housed away from the engine and would have power given or taken by means of a gear connection.
I finally understand it! Finally! I was getting confused, because I couldn't figure out how the combusted air exhausted out of the engine if it was used to spool the fan and the compressors. But...the air is exhausted..it just passes through the turbines first.
@sangminlee48 there called APU (auxillary power unit) which is basically a smaller jet engine and through driveshafts it powers the LPC1 and starts the rotation.
@jefferymiller59 I'm sorry but that is not strictly correct, APU does stand for Auxillary Power Unit but they are situated in the tail cone of most modern airliners. The APU drives a Load Compressor which provides pneumatic pressure which is then ducted to the engine. A pneumatically driven motor is attached to the engine accessory gearbox, the accessory gearbox is attached to the HP spool via shafts. Starter turns gearbox, gearbox rotates HP shaft.
@sangminlee48 A starter is used that uses compressed air from the APU. The starter is attached to a gearbox, and the gearbox is linked to the high spool via some shafts. Once the engine is started and is running, the high spool drives the gearbox, the gearbox has various components attached to it, an electrical generator, a hydraulic pump, a fuel pump, and an oil pump.
@EasternMerchant: I don't think so ;) I've learned 3 years to build engines...
and...
@ @pogpogcasino: The temperature of the air is at the end of the HPT nearly 650°C... It's variates from engine to engine... But 650°C are nearly exact for the CFM56-5...
@pogpogcasino The flame is started by ignitors, pretty much the same as a spark plug in a car. But once the flame is lit it burns continously, like a blow torch for example. Combustion chambers are complex in design, there's quite a lot to keeping that flame from blowing out.
@pogpogcasino The fuel/air mixture is ignited by igniters which produce electrical sparks. Then once the engine is started, it stays on because the fire in the combustor continuously ignites the incoming air/fuel mixture.
He says turbo fan, where there is a large fan in the front of the engine powered by the turbine, on these engines variations the fan moves the air that moves the plane as a reaction. On a turbojet the air that exit by the turbine that moves the plane. The turbo fan is more efficient and quieter
is there a way for an average guy living in a suburb to build an engine like this from scratch without causing a serious and/or catastrophic event? :P
@EasternMerchant Jet engines require very high quality/expensive materials and very precise manufacturing and tolerances because they spin so fast, and have very high pressures and temperatures. If you don't use the proper materials, you will have a catastrophic failure like a compressor disc explosion due to centrifugal force or the turbines will melt. Also, if there is even a slight imbalance in the rotating parts, it will practically self-destruct due to the high speed.
Can someone please explain to me why at 2:45 in the combustor stage, that the ignited fuel air mixture doesnt force back the air against the grain thus creating unnecessary load on the compressure sections? Or maybe it does but balances out in a positive thrust instead of negative
@ricktbdgc it's probably because for one the air is already flowing in that direction and also the high pressure turbine might suck the air toward the back
@coastermania17@ricktbdgc The turbines don't do any sucking. They are powered by the exhaust as it flows through them. The reason the fuel/air mixture does not go back out the front of the engine is because of the enormous pressure coming from the compressors and forcing the exhaust out the back of the engine.
@ricktbdgcThere is a physics explanation to your problem...the shape of the LP and HP blades are like wings. On one surface they compress the air and on the other side they expand the air justi like a wing. If the tuel air mix are combined at too low or too high a speed then the engine may stall after ignition. It's all about "suck squeez bang blow" which has to happen at the right speed and airflow through the engine. Sorry that I can't squeeze more science in a short reply.
@ricktbdgc The highest pressure in the engine is actually at the exit of the high pressure compressor. The volume of the duct increases at the combustor and at the low pressure turbine so the pressure decreases. So the easiest path for the air to take is rearwards (high to low). This is only true when the high pressure compressor is working properly, if there's a problem that causes the compressor blades to stall, what you describe actually happens and this is called an engine surge.
This is a RAM-jet engine, if I remember correctly. The problem is that the air needs to be slowed down.
There's a new technology in the works called a SCRAM-jet, which doesn't need to slow down the air, so the ar can move at supersonic speed, making it possible to go up to speeds like MACH-15.
@antiHUMANDesigns Actually it's just a turbofan. It states in the video that they use the pw-4102 engine for their example. Turbofans are what are used on civilian transport craft. I've never heard of a passenger jet with ramjets.
I'm a Pratt & Whitney technical instructor on the PW4000 and this is by far the best video animation and narration I've see on the basic operation of a jet engine. I wish I had this to animation to show my classes where did you get it?
This animation is very-very good image. Because it's clear and excellent idea and usable to me and make many persons like me knowing the process working jet engine. If you don't mine I wish in this web provide all the text was read. So I can study and improve my little English too. Thanks.
As an engineer, that is the best explanation I have ever heard. It's the first video I have found that breaks down the high and low spools and explains their function. Awesome video!
yes I found a site where you can VALUE YOUR YOUTUBE CHANNEL (or web or blog) and you get help on how and where to sell it so you can make some good money with that !!! site is mysitemymoney . com
@thegertkenator Someone who was inspired. A British pilot named Sir Frank Whittles is credited for designing the first turbojet engine back in 1930. This engine flew successfully in April, 1937. Hans Von Ohain had the same idea, but was built different from that of Sir Frank. A small airplane was made to test Hans engine, and in 1939 the Heinkel HE178 flew successfully for the first time. The pilot's name was Erich Warsitz. I could be wrong.
The starter is pneumatically powered and starts by turning the stage two turbines using compressed air. Then the ignitors are activated, and finally the fuel is added. It is done in this sequence to make sure the air is flowing in the proper direction before adding fuel.
Just a question, how are those engines started? (When there's no air speed and the blades are at 0 rpm). Is the burning of fuel alone without compression enough to start turning the blades? Regards
@alfonsmc external air and power or via APU, external air/power is a equipment connected on ground to supply both power and air, APU is a small engine behind a plane if external power/air is not available on ground that gives power and air to the engine especially on engine start.
Excellent video! I had read and seen several times that there are a series of compressor and turbines but I always wondered what drives them, what makes them spin. Now I know!
There are dual mode engines that can vary the bypass ratio, thus having the advantage to both the turbojet and turbofan.
This allows such an engine to be used over large range operations but have a short takeoff distance but due to the added overall expense and the fact that it is not as efficient as a pure turbofan it has not hit the market.
Another flavor of engine is the turboprop, better for slow speed operation but even more efficient.
it would be good to see it all in exact detail. i would like to see some actual cad plan so i can examine jet enigne parts down to every little fine detail. these quick descriptions stil dont give you a thorough understanding. you really need to see the real thing. i would love to see a video of a jet engine being manafactured and every step show including everything not just little clips of some parts beign assembled
Something is wrongg about this video. If 80% of the thrust is generated by the fan, then a turbojet should theoretically have less thrust than a turbofan
@jeanlucncoelho a turbojet actually produces lesser thrust than turbofan engines, that is why turbofans are so popular today....turbojets are more noise, and less thrust!!!!!
@retardedcentaur if that were true than turbofans would be supersonic, not turbojets. Turbofans are actually more popular because they are more efficient than turbojets
@jeanlucncoelho brother, let me clear the clouds for you....tubrojet powered military jets are supersonic because they are designed that way, and not to mention the comparatively smaller loads they carry...if we go by power to weight ratio, turbofans do produce much more thrust - courtesy the large contribution of the bypass air...remember, thrust is a function of mass airflow and the degree to which the mass is accelerated, so more mass airflow implies more thrust....
@jeanlucncoelho but we were talkin about THRUST producing capability, and not speed or efficiency...turbojets are supersonic not because they produce more thrust, bt because of the lesser inlet diameter and other factors which counteract drag and shockwave formation (eg. the C-D duct)....large diameter turbofans are impractical for supersonic speeds...
Brother, what u say justifies my point, that turbofans do produce more thrust than a turbojet....
@jeanlucncoelho The exhaust speed of the of a turbofan does not depend on the diameter of the entire engine. It depends on the diameter of the fan in relation to the core...in other words, the bypass ratio. The higher the bypass ratio, the slower the exhaust. The lower the bypass ratio, the faster the exhaust. A turbojet has a bypass ratio of zero, so it has the highest exhaust speed. Of course, the exhaust speed of a turbofan can be greatly increased with an afterburner.
@jeanlucncoelho Of course an afterburner increases fuel consumption, but you can't say by 200%. That depends on a lot of different things. And yes, a turbojet is more efficient for very high speed flight.
All modern jet fighters, as far as I know, use low-bypass afterburning turbofans. The F-22 Raptor can supercruise, that is, fly supersonic without using afterburners. That's because it has very low-bypass turbofan engines. As far as thrust, it is determined by the amount air is being moved and how much that air is being accelerated. A turbofan produces more thrust than a turbojet with the same core up to a certain point.
@jeanlucncoelho No the SR-71 used a ramjet. A ramjet is a jet engine where the air is traveling so fast (Ex. Supersonic speeds) that compressors are unnecessary. The rest of the process is the same as described here. I believe there are compressors for the low speeds necessary for takeoff and landing but after its going fast enough the air is channeled away from the compressors. They forgot to add that the engine also powers a generator and air compressor to power and pressurize the airplane.
@Silavite i know what a ramjet is. The j-58 (the sr-71s engine) was a variable cycle jet engine. I.E. it was a turbojet inside of a fan-assisted ramjet. What it did is this: initially the air was compressed by a shock cone. Then it could go to 2 places: the turbojet or it could be sent directly into the afterburner. the ratio of bypass air depends on the velocity of the aircraft with it being 0% and mach 0 and 100% at mach 3.
If the bypass ratio of a turbofan is too great, then the core will not have enough power to spin the fan fast enough. So even though it may move a lot air, it will move it at an impractically slow speed. So, in that case, a turbojet version of the engine (the core without the fan and low pressure turbine) will produce more thrust.
One last thing: A turbofan has a lower thrust specific fuel consumption than a turbojet. And the higher the bypass ratio (up to that certain point), the lower the thrust specific fuel consumption. So if you have a turbojet and turbofan with the same thrust, the turbofan will use less fuel. In other words, you can get more thrust using less fuel with a turbofan. Hope all this info helps!
@jeanlucncoelho u still are not dead right, bt very close...and, somehw u seem to have undrstood that turbofans produce more thrust compared to a turbojet...and that was the only point of our discussion...
or is it that u still want to say that turbojets have higher thrust capability???
@jeanlucncoelho and to why turbofans are not supersonic, it is because the large diameter of the fan...the fan tips produce shock waves when above sonic velocity....this problem is not a case in turbojets....also the turbofan powered aircraft are not designed that way....but even so, modern jetliners are known to fly in the 0.8 - 1.2 Mach range...
The initial air comes from the APU bleed air. When put to 'start' in the overhead panel inside flightdecK, it will send a signal to a starter valve solenoid to move the starter valve butterfly valve to full open which allows high rate of bleed air gushed through it and it will turned the pneumatic starter. This pneumatic starter is coupled to the accesory gear box and also angle gear box that will spool stage 3 turbine with the shaft connected to fan blade(N1).
The initial air comes from the APU bleed air. When put to 'start' in the overhead panel inside flightdecK, it will send a signal to a starter valve solenoid to move the starter valve butterfly valve to full open which allows high rate of bleed air gushed through it and it will turned the pneumatic starter. This pneumatic starter is coupled to the accesory gear box and also angle gear box that will spool stage 3 turbine with the shaft connected to fan blade(N1)
OMG..Whatever happened to the 80s documentaries which explained so god dam well!!! Today there are so much assumptions that the audience knows a lot and they skip explaining so patiently and detailed way and at the end of it your left scratching your head about what is an Combustor!! Fat chance we would have heard such an beautiful explanation these days!!!
@MrHobiecat the way I see it, the orientation of the blades makes the air go that way, then the momentum of the compressed air keeps the flow going in that direction.
@ben5056 no, that cant be it. The pressure keeps the rotors spinning so there has to be something else that keeps the gas from blowing out the front.
The only thing I can think of is maybe the pressure in the combustion chamber is lower than the pressure in the compressor stage, and the resistance to flow out the back is much lower than the resistance out the front.
But intuitively I think Im still missing something.
@MrHobiecat oh yes you are right, if the pressure keeps increasing the air would be forced to go to lower air pressure areas. Maybe I'll be able to answer that when I get my degree in a couple years !!
@ben5056 there is probably also the issue of volume. It should not take a lot of high pressure fresh air blown into the combustion chamber to burn the fuel, which then creates a much larger volume of exhaust gas, at a lower pressure than the injected air?
Its not intutively obvious, guess thats why it took so many years for it to be invented.
But it is pretty cool, no valves, and only two moving parts (assemblies)
@MrHobiecat jet engines are definitely complex, and also fascinating. I wonder what the ratio between the kinetic energy and the chemical energy is. It would be interesting to compare it's efficiency with that of a combustion engine.
@ben5056 A few jet turbine cars were built, the original batmobile for the TV series in the 60s was one. I think on a car they are not as fuel effecient, but on a jet plane, a fully loaded 747 gets TWICE the gas mileage (per person) than a Prius with one passenger.
Flying is the only way to go. A single passenger plane like a sailplane, with a small engine, would get phenonimal mileage at low speeds (less than 60mph).
After you watch this video, check-out Pratt and Whitney, GE and Rolls-Royce. Then compare each large commercial engine. Tell me which one is the best.
What did the huge Titanium turbin at the front of the Pratt & Whitney Turbofan Engine say to Matt Damon when was boarding the plane?......................I'm a huge fan!
Interesting, now I wonder how they got all these ratios and if they could be improved.
niko4691k 1 week ago
Isn't there a generator mounted before the hot air leaves the turbine, that produces the energy for the air conditioning etc. ???
DemonZapan 1 week ago
@DemonZapan I think the electronic starter motor doubles as a generator in flight (all DC motors can double as generators). However, this motor is housed away from the engine and would have power given or taken by means of a gear connection.
SaucyJake 1 week ago
Duh!
UncleImpala 1 week ago
Could you repeat that?
rofyle 3 weeks ago
Thanxx very much for the video.........I was kind of confused with what exactly the turbines do.......but i finally got it from this video
1alfazulu 3 weeks ago in playlist Helicopter
I finally understand it! Finally! I was getting confused, because I couldn't figure out how the combusted air exhausted out of the engine if it was used to spool the fan and the compressors. But...the air is exhausted..it just passes through the turbines first.
636Castle 4 weeks ago
I think Richard Nixon had done enough community service by the time he voiced this teaching video.
krevno 4 weeks ago
Ahh the low pressure Turban.
Not a Turbine.
archergareth 1 month ago
what powers the spin of the blades?
XEziOXxx 2 months ago
@XEziOXxx The turbines in the rear of the engine power the fan and compressors at the front.
jetengine7 2 months ago
@XEziOXxx
jet fuel?
Dankniggah420 1 month ago
mr.muhammad ayub bajwa making new design jet engine ayub_4_victoria jet engines for aero space technology.
flipperpump52891 2 months ago
0:47
I wonder what powers the initial turbine rotation.
sangminlee48 2 months ago
@sangminlee48 there called APU (auxillary power unit) which is basically a smaller jet engine and through driveshafts it powers the LPC1 and starts the rotation.
jefferymiller59 2 months ago
@jefferymiller59 I'm sorry but that is not strictly correct, APU does stand for Auxillary Power Unit but they are situated in the tail cone of most modern airliners. The APU drives a Load Compressor which provides pneumatic pressure which is then ducted to the engine. A pneumatically driven motor is attached to the engine accessory gearbox, the accessory gearbox is attached to the HP spool via shafts. Starter turns gearbox, gearbox rotates HP shaft.
MrIfixplanes 2 months ago
@sangminlee48 A starter is used that uses compressed air from the APU. The starter is attached to a gearbox, and the gearbox is linked to the high spool via some shafts. Once the engine is started and is running, the high spool drives the gearbox, the gearbox has various components attached to it, an electrical generator, a hydraulic pump, a fuel pump, and an oil pump.
MrIfixplanes 2 months ago
I have a fan from wal-mart, will that do?
logicCplusplus 2 months ago
Its chuck norrisses fart
averyaccordion 2 months ago
very good for study matrieal..............
rohits844 2 months ago
the what now? ?
bmxguppi 2 months ago
cool, now i can fucken build one now
volkscom 2 months ago
Lol "High pressure Turban"
xWeMakeVidsx 3 months ago 3
i still dont understand
bonzo354 3 months ago
@EasternMerchant: I don't think so ;) I've learned 3 years to build engines...
and...
@ @pogpogcasino: The temperature of the air is at the end of the HPT nearly 650°C... It's variates from engine to engine... But 650°C are nearly exact for the CFM56-5...
Jules110489 3 months ago
Lol! you never mention how the flames being ignited. Confidential?
pogpogcasino 3 months ago
@pogpogcasino Probably the sheer pressure
Shrike2415 3 months ago
@pogpogcasino "Raises the temp by 1000 degrees after passing thru the compressor" I'm sure it ignites just from the heat and pressure.
kevindolin2 3 months ago
@pogpogcasino The flame is started by ignitors, pretty much the same as a spark plug in a car. But once the flame is lit it burns continously, like a blow torch for example. Combustion chambers are complex in design, there's quite a lot to keeping that flame from blowing out.
MrIfixplanes 2 months ago
@pogpogcasino The fuel/air mixture is ignited by igniters which produce electrical sparks. Then once the engine is started, it stays on because the fire in the combustor continuously ignites the incoming air/fuel mixture.
jetengine7 2 months ago
Why is he saying turban? That's what you put on your head! It's TUR - BINE
Deonnh 3 months ago
@Deonnh
He says turbo fan, where there is a large fan in the front of the engine powered by the turbine, on these engines variations the fan moves the air that moves the plane as a reaction. On a turbojet the air that exit by the turbine that moves the plane. The turbo fan is more efficient and quieter
madmax01 3 months ago
@Deonnh he's saying TurboFan not Turban
kdog0011 3 months ago
is there a way for an average guy living in a suburb to build an engine like this from scratch without causing a serious and/or catastrophic event? :P
EasternMerchant 3 months ago
@EasternMerchant Jet engines require very high quality/expensive materials and very precise manufacturing and tolerances because they spin so fast, and have very high pressures and temperatures. If you don't use the proper materials, you will have a catastrophic failure like a compressor disc explosion due to centrifugal force or the turbines will melt. Also, if there is even a slight imbalance in the rotating parts, it will practically self-destruct due to the high speed.
jetengine7 2 months ago
Excellent, wonderful explanation :D thanks a lot.
MultiBrados 3 months ago
Magic, got it! ;)
RealCadde 3 months ago
dope shit, very simple(explanation).
mhma1976 3 months ago
Turban lol
jimass69 4 months ago
Learn something every day. Thank you!
Derangedteddy 4 months ago
Can someone please explain to me why at 2:45 in the combustor stage, that the ignited fuel air mixture doesnt force back the air against the grain thus creating unnecessary load on the compressure sections? Or maybe it does but balances out in a positive thrust instead of negative
ricktbdgc 4 months ago
@ricktbdgc it's probably because for one the air is already flowing in that direction and also the high pressure turbine might suck the air toward the back
coastermania17 4 months ago
@coastermania17 @ricktbdgc The turbines don't do any sucking. They are powered by the exhaust as it flows through them. The reason the fuel/air mixture does not go back out the front of the engine is because of the enormous pressure coming from the compressors and forcing the exhaust out the back of the engine.
jetengine7 2 months ago
@ricktbdgcThere is a physics explanation to your problem...the shape of the LP and HP blades are like wings. On one surface they compress the air and on the other side they expand the air justi like a wing. If the tuel air mix are combined at too low or too high a speed then the engine may stall after ignition. It's all about "suck squeez bang blow" which has to happen at the right speed and airflow through the engine. Sorry that I can't squeeze more science in a short reply.
sgtish 3 months ago
@sgtish
cool i love science
ricktbdgc 3 months ago
@sgtish
also, thats what she said!
ricktbdgc 3 months ago
@ricktbdgc The highest pressure in the engine is actually at the exit of the high pressure compressor. The volume of the duct increases at the combustor and at the low pressure turbine so the pressure decreases. So the easiest path for the air to take is rearwards (high to low). This is only true when the high pressure compressor is working properly, if there's a problem that causes the compressor blades to stall, what you describe actually happens and this is called an engine surge.
MrIfixplanes 3 months ago
I love aviation and everything related to it.. Awesome!!!
titohuertas 4 months ago
simply wow o love these thing
ba20055 4 months ago
well.... I am now qualified to build a jet engine. I will now go learn how to build a V8 engine.
AlEspinoza1 4 months ago
I wish i had a high pressure turbin.
campbelljordanable 4 months ago
15 dislikes will have to take a boat
donperry1 4 months ago 33
@donperry1 boats rocks!
02thered 4 months ago
@donperry1 Or Props
Hydrolish02 3 months ago
@donperry1 There is no escape, even RCIs Radiance class are powered by gas turbines turning generators.
endsleighplace 3 months ago
@donperry1 or walk
anichavda82 2 months ago
greek pleace :(
STATHISBSG 5 months ago
This is a RAM-jet engine, if I remember correctly. The problem is that the air needs to be slowed down.
There's a new technology in the works called a SCRAM-jet, which doesn't need to slow down the air, so the ar can move at supersonic speed, making it possible to go up to speeds like MACH-15.
antiHUMANDesigns 5 months ago
@antiHUMANDesigns Actually it's just a turbofan. It states in the video that they use the pw-4102 engine for their example. Turbofans are what are used on civilian transport craft. I've never heard of a passenger jet with ramjets.
obliviousfafnir01 5 months ago
this is the best explanation I've seen so far.
Gary190tube 5 months ago 56
@rocketpropulsion : now 15 ppl :P
TheAero94 5 months ago
it was exciting up to 1 minute, then he started sounding like my high school history teacher, who had a great skill of making people fall asleep
abelucious 5 months ago
very easy to understand..
fahrizal2002 6 months ago
thrust= me + your girlfriend + doggie style
XmojotronX 6 months ago
The description should read "dual spool" rather than "duel spool".
lumpheadthump 6 months ago
and still china cant figure it out when its all right here
USAmilitarypower 6 months ago
its a turboprop not a jet engine theres a diffrence ya know
Awesomeness6699 6 months ago
@Awesomeness6699 its a turbofan not a turboprop. there's a difference you know hahaha
bobdudeman1988 6 months ago
@Awesomeness6699 Were you trying to make a joke, or did you really think that this was a turboprop engine?
lumpheadthump 6 months ago
@Awesomeness6699 Haha FAIL.
1098kicksass 4 months ago
It is always a serious video when they throw in Newton.
oracle2world 6 months ago
Amen!
caioghiotto 6 months ago
I'm a Pratt & Whitney technical instructor on the PW4000 and this is by far the best video animation and narration I've see on the basic operation of a jet engine. I wish I had this to animation to show my classes where did you get it?
JLEROUX82 6 months ago
Excellent animation to understand jet-engine working principle. Very good for the beginners.
nkdandekar 7 months ago
What kind of technology would be needed to to make a jet that flies and maneuvers so swiftly and flawless like a house fly?
boarding5401 7 months ago
This animation is very-very good image. Because it's clear and excellent idea and usable to me and make many persons like me knowing the process working jet engine. If you don't mine I wish in this web provide all the text was read. So I can study and improve my little English too. Thanks.
agungfpub1958 7 months ago
the nazis were the first to develope jet engines. we can thank them for that.
lvll138inrs 7 months ago
As an engineer, that is the best explanation I have ever heard. It's the first video I have found that breaks down the high and low spools and explains their function. Awesome video!
drbaker4 7 months ago
This has been flagged as spam show
yeah i found a site where you can VALUE YOUR YOUTUBE CHANNEL (or blog or
web) then you get help on how and where to sell it so you can make some good
money with that. site is mysitemymoney com
radionix02 7 months ago
This has been flagged as spam show
yes I found a site where you can VALUE YOUR YOUTUBE CHANNEL (or web or blog) and you get help on how and where to sell it so you can make some good money with that !!! site is mysitemymoney . com
yourplacetotravelCOM 7 months ago
that's one hell of a fan
vistaway3008 7 months ago
Who in the hell could think up something like that?? Unbelievable.
thegertkenator 7 months ago
@thegertkenator Someone who was inspired. A British pilot named Sir Frank Whittles is credited for designing the first turbojet engine back in 1930. This engine flew successfully in April, 1937. Hans Von Ohain had the same idea, but was built different from that of Sir Frank. A small airplane was made to test Hans engine, and in 1939 the Heinkel HE178 flew successfully for the first time. The pilot's name was Erich Warsitz. I could be wrong.
Psychonaut2021 7 months ago
and here i thought jet engines worked like a car's turbocharges.
kurdishmob 7 months ago
that does not look like a turban too me
Sorsby07 8 months ago
@Sorsby07 lawl
eeg10 7 months ago
The starter is pneumatically powered and starts by turning the stage two turbines using compressed air. Then the ignitors are activated, and finally the fuel is added. It is done in this sequence to make sure the air is flowing in the proper direction before adding fuel.
spacart1 8 months ago
Just a question, how are those engines started? (When there's no air speed and the blades are at 0 rpm). Is the burning of fuel alone without compression enough to start turning the blades? Regards
alfonsmc 8 months ago
@alfonsmc external air and power or via APU, external air/power is a equipment connected on ground to supply both power and air, APU is a small engine behind a plane if external power/air is not available on ground that gives power and air to the engine especially on engine start.
wayneroughneckz 8 months ago
Excellent video! I had read and seen several times that there are a series of compressor and turbines but I always wondered what drives them, what makes them spin. Now I know!
SteelSnail 8 months ago
There are dual mode engines that can vary the bypass ratio, thus having the advantage to both the turbojet and turbofan.
This allows such an engine to be used over large range operations but have a short takeoff distance but due to the added overall expense and the fact that it is not as efficient as a pure turbofan it has not hit the market.
Another flavor of engine is the turboprop, better for slow speed operation but even more efficient.
Arabhacks 8 months ago
14 people who dislike the video should be sucked in by P & W GE-90 turbofan engine ... :P
aahan1 8 months ago
@aahan1 The GE90 is made by General Electric, not Pratt & Whitney. That's what the "GE" in GE90 stands for!
jetengine7 8 months ago
@aahan1 The GE90 is made by General Electric, not Pratt & Whitney. That's what the "GE" in GE90 stands for!
And yes, they should be sucked into a GE90. : )
jetengine7 8 months ago
@jetengine7 : yeah, u r right. funny things is, I knew what GE stands for, still I added P & W .. :D
aahan1 8 months ago
Engineering at its best.
aonutube 8 months ago
TOO COMPLICATED
Outoftheclique 9 months ago
Thanks!!!
genrolecaspe 9 months ago
it would be good to see it all in exact detail. i would like to see some actual cad plan so i can examine jet enigne parts down to every little fine detail. these quick descriptions stil dont give you a thorough understanding. you really need to see the real thing. i would love to see a video of a jet engine being manafactured and every step show including everything not just little clips of some parts beign assembled
210482fmj 9 months ago
@210482fmj that, my friend, would be worth its weight in gold! Thats the top secret stuff only the engineers with the thickest of glasses get to see!
iriddell1 8 months ago
@iriddell1 lol
Graywolf116 8 months ago
centrifugal
TYMENIOUS 9 months ago
Why does he call it a "Turbin"?
GeekLove100u 9 months ago
it's newton's third law tyvm
MsSemisemi 9 months ago
Something is wrongg about this video. If 80% of the thrust is generated by the fan, then a turbojet should theoretically have less thrust than a turbofan
jeanlucncoelho 9 months ago
@jeanlucncoelho a turbojet actually produces lesser thrust than turbofan engines, that is why turbofans are so popular today....turbojets are more noise, and less thrust!!!!!
retardedcentaur 9 months ago
Comment removed
jeanlucncoelho 9 months ago
@retardedcentaur if that were true than turbofans would be supersonic, not turbojets. Turbofans are actually more popular because they are more efficient than turbojets
jeanlucncoelho 9 months ago
@jeanlucncoelho brother, let me clear the clouds for you....tubrojet powered military jets are supersonic because they are designed that way, and not to mention the comparatively smaller loads they carry...if we go by power to weight ratio, turbofans do produce much more thrust - courtesy the large contribution of the bypass air...remember, thrust is a function of mass airflow and the degree to which the mass is accelerated, so more mass airflow implies more thrust....
retardedcentaur 9 months ago
@retardedcentaur Now let me clarify something 4 u:
Turbofan: Works by accelerating large ammounts of SLOW moving air = more fuel efficient at slow speeds but doesnt work in high speeds.
Turbojet: Accelerates small ammounts of FAST moving air = can reach higher speeds and have optimal working velocities > mach 1.
jeanlucncoelho 9 months ago
@jeanlucncoelho but we were talkin about THRUST producing capability, and not speed or efficiency...turbojets are supersonic not because they produce more thrust, bt because of the lesser inlet diameter and other factors which counteract drag and shockwave formation (eg. the C-D duct)....large diameter turbofans are impractical for supersonic speeds...
Brother, what u say justifies my point, that turbofans do produce more thrust than a turbojet....
retardedcentaur 9 months ago
@retardedcentaur smaller diameter = more thrust at higher speers
larger diameter = more thrust at lower speeds
jeanlucncoelho 9 months ago
@jeanlucncoelho The exhaust speed of the of a turbofan does not depend on the diameter of the entire engine. It depends on the diameter of the fan in relation to the core...in other words, the bypass ratio. The higher the bypass ratio, the slower the exhaust. The lower the bypass ratio, the faster the exhaust. A turbojet has a bypass ratio of zero, so it has the highest exhaust speed. Of course, the exhaust speed of a turbofan can be greatly increased with an afterburner.
jetengine7 8 months ago
@jetengine7 yes but an afterburner would increase the fuel consumption by 200%. At higher speers it is much more efficient to use a turbojet
jeanlucncoelho 8 months ago
Comment removed
jetengine7 8 months ago
Comment removed
jetengine7 8 months ago
This has been flagged as spam show
@jeanlucncoelho Of course an afterburner increases fuel consumption, but you can't say by 200%. That depends on a lot of different things. And yes, a turbojet is more efficient for very high speed flight.
jetengine7 8 months ago
All modern jet fighters, as far as I know, use low-bypass afterburning turbofans. The F-22 Raptor can supercruise, that is, fly supersonic without using afterburners. That's because it has very low-bypass turbofan engines. As far as thrust, it is determined by the amount air is being moved and how much that air is being accelerated. A turbofan produces more thrust than a turbojet with the same core up to a certain point.
jetengine7 8 months ago
@jetengine7 thats exactly why the sr71 used a modified turbojet
jeanlucncoelho 8 months ago
@jeanlucncoelho No the SR-71 used a ramjet. A ramjet is a jet engine where the air is traveling so fast (Ex. Supersonic speeds) that compressors are unnecessary. The rest of the process is the same as described here. I believe there are compressors for the low speeds necessary for takeoff and landing but after its going fast enough the air is channeled away from the compressors. They forgot to add that the engine also powers a generator and air compressor to power and pressurize the airplane.
Silavite 8 months ago
@Silavite i know what a ramjet is. The j-58 (the sr-71s engine) was a variable cycle jet engine. I.E. it was a turbojet inside of a fan-assisted ramjet. What it did is this: initially the air was compressed by a shock cone. Then it could go to 2 places: the turbojet or it could be sent directly into the afterburner. the ratio of bypass air depends on the velocity of the aircraft with it being 0% and mach 0 and 100% at mach 3.
jeanlucncoelho 8 months ago
If the bypass ratio of a turbofan is too great, then the core will not have enough power to spin the fan fast enough. So even though it may move a lot air, it will move it at an impractically slow speed. So, in that case, a turbojet version of the engine (the core without the fan and low pressure turbine) will produce more thrust.
jetengine7 8 months ago
One last thing: A turbofan has a lower thrust specific fuel consumption than a turbojet. And the higher the bypass ratio (up to that certain point), the lower the thrust specific fuel consumption. So if you have a turbojet and turbofan with the same thrust, the turbofan will use less fuel. In other words, you can get more thrust using less fuel with a turbofan. Hope all this info helps!
jetengine7 8 months ago
@jetengine7 Thank you. Finally someone understands. The turbofan is more fuel efficient but the turbojet has more maximum thrust.
jeanlucncoelho 8 months ago
@retardedcentaur dont forget that is a turbojet receiving only 15% of the air that drives the fan
jeanlucncoelho 9 months ago
@jeanlucncoelho u still are not dead right, bt very close...and, somehw u seem to have undrstood that turbofans produce more thrust compared to a turbojet...and that was the only point of our discussion...
or is it that u still want to say that turbojets have higher thrust capability???
retardedcentaur 9 months ago
@jeanlucncoelho and to why turbofans are not supersonic, it is because the large diameter of the fan...the fan tips produce shock waves when above sonic velocity....this problem is not a case in turbojets....also the turbofan powered aircraft are not designed that way....but even so, modern jetliners are known to fly in the 0.8 - 1.2 Mach range...
retardedcentaur 9 months ago
one couldnt have explained it in a better way :-]
thedeerish 9 months ago 11
@thedeerish graphics makes it like u r deep inside it !
ba20055 4 months ago
Такой принцип работы турбин не самый оптимальный.
ssmNikolaev 9 months ago
Understood how jet engine works but, I want to know how to start it. ...how does first air go into the engine???
pilgrimgoestonaos 10 months ago
@pilgrimgoestonaos
The initial air comes from the APU bleed air. When put to 'start' in the overhead panel inside flightdecK, it will send a signal to a starter valve solenoid to move the starter valve butterfly valve to full open which allows high rate of bleed air gushed through it and it will turned the pneumatic starter. This pneumatic starter is coupled to the accesory gear box and also angle gear box that will spool stage 3 turbine with the shaft connected to fan blade(N1).
alvliew 9 months ago
@pilgrimgoestonaos
The initial air comes from the APU bleed air. When put to 'start' in the overhead panel inside flightdecK, it will send a signal to a starter valve solenoid to move the starter valve butterfly valve to full open which allows high rate of bleed air gushed through it and it will turned the pneumatic starter. This pneumatic starter is coupled to the accesory gear box and also angle gear box that will spool stage 3 turbine with the shaft connected to fan blade(N1)
alvliew 9 months ago
nice work.................
29riteshkakkar 10 months ago
OMG..Whatever happened to the 80s documentaries which explained so god dam well!!! Today there are so much assumptions that the audience knows a lot and they skip explaining so patiently and detailed way and at the end of it your left scratching your head about what is an Combustor!! Fat chance we would have heard such an beautiful explanation these days!!!
KarthikSoun 10 months ago
the thing I never understood, you end up with a pressurized combustion chamber at the back, with fins/blades on both sides.
Why doest the hot gas blow out both ends? How does it know its suppose to only pressurize the back exit and not blow out the front of the engine?
MrHobiecat 10 months ago
@MrHobiecat the way I see it, the orientation of the blades makes the air go that way, then the momentum of the compressed air keeps the flow going in that direction.
ben5056 10 months ago
@ben5056 no, that cant be it. The pressure keeps the rotors spinning so there has to be something else that keeps the gas from blowing out the front.
The only thing I can think of is maybe the pressure in the combustion chamber is lower than the pressure in the compressor stage, and the resistance to flow out the back is much lower than the resistance out the front.
But intuitively I think Im still missing something.
MrHobiecat 10 months ago
@MrHobiecat oh yes you are right, if the pressure keeps increasing the air would be forced to go to lower air pressure areas. Maybe I'll be able to answer that when I get my degree in a couple years !!
ben5056 10 months ago
@ben5056 there is probably also the issue of volume. It should not take a lot of high pressure fresh air blown into the combustion chamber to burn the fuel, which then creates a much larger volume of exhaust gas, at a lower pressure than the injected air?
Its not intutively obvious, guess thats why it took so many years for it to be invented.
But it is pretty cool, no valves, and only two moving parts (assemblies)
MrHobiecat 10 months ago
@MrHobiecat jet engines are definitely complex, and also fascinating. I wonder what the ratio between the kinetic energy and the chemical energy is. It would be interesting to compare it's efficiency with that of a combustion engine.
ben5056 10 months ago
@ben5056 i dont know really actually, but heard its about 40-50% for jet engine, and gasoline engine is around 60%
harismokhtar 10 months ago
@ben5056 A few jet turbine cars were built, the original batmobile for the TV series in the 60s was one. I think on a car they are not as fuel effecient, but on a jet plane, a fully loaded 747 gets TWICE the gas mileage (per person) than a Prius with one passenger.
Flying is the only way to go. A single passenger plane like a sailplane, with a small engine, would get phenonimal mileage at low speeds (less than 60mph).
MrHobiecat 10 months ago
How does the engine spin? What make it spinning?
phayoun 10 months ago
@phayoun read further down in the comments, An electric motor spins up the rotors from a cold start.
MrHobiecat 10 months ago
This has been flagged as spam show
fuck i am confused. lol.
seatgurus 11 months ago
I took like 3 pages of notes to understand it XDDD My brain is full 0 gb free of 1gb naow
TooSlowForSpeed 11 months ago
After you watch this video, check-out Pratt and Whitney, GE and Rolls-Royce. Then compare each large commercial engine. Tell me which one is the best.
paduajoseph 11 months ago
11 people STILL didn't understand!
rocketpropulsion 11 months ago 18
lol
sonictherevenge 5 months ago
thank you
tomatowatcher 11 months ago
It's interesting that 85% of that air comes out the same only faster. I always thought all the air was ignited with fuel
SovietUnity 11 months ago
I finally understand! :D thanks!
yaricksgym 11 months ago
I hear robot narrating.
kcssweetboy 1 year ago
What did the huge Titanium turbin at the front of the Pratt & Whitney Turbofan Engine say to Matt Damon when was boarding the plane?......................I'm a huge fan!
NickBottini 1 year ago 40
@NickBottini LOL this has nothing to do with turbofan technology.
paduajoseph 11 months ago
@NickBottini What a Colonel you are Snottini :D
efzt 6 months ago
Gr8 video..... luv the expaination!!!!
karandarvesh 1 year ago
very informative video... thanku very much... :)
assimhussain 1 year ago
Thumbs up for simultaneous Suck-Squeeze-Bang-Blow Action!
ThatKidKnows 1 year ago
@ThatKidKnows
"suck-squeeze-bang-blow action"
That sounds a lot like how I spent last weekend.
RCHairbrush 11 months ago 32
@RCHairbrush Giggity Giggity Goo!
ThatKidKnows 11 months ago
@RCHairbrush Your comment is awesome! haha...respect man ;o)
dntist 10 months ago
@RCHairbrush lol u fag :D
Sylvanas17 9 months ago
@RCHairbrush I guess you produced a lot of thrust!! =D
twistedyogert 5 months ago
very good!!!!
cleuberaraujo 1 year ago
Hey I understand now! Oh well back to school to study plasma and ion jets.
shardsofsteel 1 year ago
very nice discussion!! :))
tunggoy7 1 year ago
I like it
frank55944 1 year ago
this video answered so many questions i had that other videos couldn't
rey619yomama 1 year ago
BTW - this was a very fascinating video.
SlamDuncDrummer 1 year ago