Thanks for the great videos! I found these a couple of days ago and I'm attempting to go through the entire playlist. You said that the shaft to drive the gear box and accessories was located at the third stage of the HPC. But it looks like the shaft to the accessory gear box on the diagram that I have (CFM 56-7B) passes between where the LPC and HPC are located. Then again, it is kind of hard to show on a 2D diagram a shaft which comes out of the page to a gear box on the side of the engine.
@tvirus457 ... If I said it that way, it's wrong. The radial drive shaft would be driven by the HPC, and the most sensible place to do that would be from one end of it, and the cold end would be better than the hot end.
Jay, why does the thrust bearing for the LM1500 come vacuum packed? Isn't it just another piece of metal like the rest of the engine which is always exposed to air? I was thinking maybe corrosion prevention?
@343jonny It's not really vacuum packed, but it's packed in oil to prevent corrosion. The packaging is sealed to prevent leakage, and looks vacuum packed to use as little oil as possible.
@viperdriver82 You're right! I couldn't reshoot the video, and I forgot to fix that mistake with annotations. I was wondering when I would be caught.
The reason I messed up : because the 330 is one of my favorite airliners. It looks like it giant bird that sticks its neck out far forward because it is so happy to fly.
@AgentJayZ I am a Jordanian Mechanical Engineer, I thank you very much for the very useful videos you produce, I searched a lot for a specialized information about gas turbine and jet engines for long time, and I didn't find any valuable thing, but discovering your channel was for me like discovering a treasure. THANK YOU and KEEP IT UP, I wish you best luck.
@lazystart I think you are referring to the active clearance control system, which controls the clearance between the turbine blade tips and the turbine casing/liners. What is actually altered here is not the length of the blades, but the diameter of the casing, resulting in an optimal clearance and minimal loss of power. This is generally achieved by cooling the turbine casing outer face by means of air pipes with little holes in them, thus controlling the expansion of the turbine casing.
If I remember correctly from advanced troubleshooting class, another factor contributing to the CFM56's efficiency is a system that thermally expands/lengthen the compressor blades to minimize the gap between the blade tip and the casing, thus reducing the amount of wasted flow-by air. I'll go find my stack o' books to verify this.
Wow I love your channel and is a really informative set of videos to help me with my growing love of jet engines. Could you help me with this question? How does the engine regulate the two systems (HP and LP) to run at different RPMs?
Jay, i think i need help. I cant stop watching your videos dude! Awesome, very informative and interesting and your excellent at getting the information across without over complicating things. Thankyou for taking the time to make them, John.
A larger fanned variant of this engine (the TF41) was used in the A-7 Corsair II. The exposed first stage is one of the reasons it was referred to as a "maneater." Careful out there.
Hey that rolls royce engine is similar to the Pratt and Whitney JT8D we have on school!! it is also a twin shaft turbine the only difference is that regardless it is also from stone age, the JT8D its a turbofan engine :P like the CFM 56 :)..
Just wanted to say that your videos are great and very helpful!!
@MonoBawuino Dude... have some respect for the old school...
The JT8-D is the most-produced large turbine engine in history. The CFM56 is a fantastic, beautiful, efficient and wonderful machine, but it dreams in its wet dreams of ever being as successful as P&W's transitional masterpiece.
@AgentJayZ hahaha i know!! there are hundreds still flying some large MROs like ITR opened large facilities just specialized in that engine ... just was trying to point that the design that CFM 56 has is polished from engines like the JT8D who was a revolutionary engine at its time in terms of design and efficiency of the civilian jet industry :) i just pointed its age because thats amazing
@MonoBawuino The CFM56 is getting on 35 years old or so, and still a fully modern engine. It will be very interesting to see what the next step will be.
One thing I was wondering (please forgive my lack of engineering knowledge), in a turbofan engine (like CFM56), does the gearbox take power from the high pressure or low pressure system?
Watching your video's has made me wish I did aeronautical engineering at university...... I ended up doing Business instead.
@daniel2001 You could think of the HP system as the essential engine, or the "core" engine... and that's what it is sometimes called. The LP system is mainly a way of harnessing the power of the HP system and using it more efficiently to propel the aircraft, and it also acts like a supercharger for the HP "core".
All of the accessories and power take-off devices take there power from the HP system.
The only thing running off the LP system is the LP speed sensor.
So now that all these parts come together, is there a real-world simulation to see how each compressor stage acts on the air? e.g. by using different coloured air pass through the engine or something along those lines?
And since you pointed out that this is the place for nice and interesting details ;-) here is a minor correction:The CFM56 has never been installed on the A330, however it is a very common powerplant on the A320 series.
Furthermore these are missing numbers for blades/vanes installed on LPC/Booster
Stage1--> 24 blades/108 vanes (on older versions i.e. CFM56-3 also 38 up to 44 blades)
Heya AgentJayZ, I've been following your channel for a while now, I really wish this stuff would've been around when I started studying Aero.Eng., would have saved me a lot LOT of looong nights sitting in front of crazy diagrams trying to figure out how Gas Turbines actually work in detail.... but I still enjoy watching this channel a lot, so THANK YOU!
Very well illustrated. And thanks for the recommendation of that book "The Jet Engine". I go nuts when i see something that interests me and I don't know exactly how it works. Your videos answer many questions.
20k for a bearing hu? Thats starting to sound like my job, everything overpriced. I discovered one of our foot long liquid oxygen hoses costs $500, and it was not even insulated! BTW, like the shirt, marines love epic meal time, insane amounts of food....and JACK DANIEL'S, im a sigle barrel select drinker myself. Gotta go for the EXTRA good stuff. :)
Hi AgentJayZ, great video, thanks! Just one question, are there any thrust bearing near the nozzle of the engine? I understand that the compressors try to move forward by blowing air backwards, but the burning gas also try to push the turbines out of the nozzle. If there is no thrust bearing near the nozzle, does it mean that the engine is designed such that the force pushing the turbines backwards is definitely large than the force pushing the compressors forward?
@crazyrum The turbines are connected to the compressors. Typically for each shaft there needs to be three bearings: supporting radial loads at the front and rear, and one supporting the axial loads somewhere else.
The thrust bearing can be anywhere along the length of the shaft, as shown here by both of them being at the front of their shaft.
@AgentJayZ Ah, I see, the ball bearing can provide force that prevent the shaft from moving either forward or backward. Since at first it has the word "thrust" on only one side of the race, I thought it is only designed to withstand force from one direction along the axle
@crazyrum Ball bearings by their basic shape can handle axial loads in either direction. Thrust bearings are slightly modified, as shown in the video, to optimize their load carrying in one axial direction, but they still can handle both.
The load on the thrust bearing in a gas turbine engine changes in magnitude with power output, but it is always in the same direction.
The axial motion on the roller bearing is less than I would have thought. The external parts, like fuel tubing, seem to leave a lot of bends and U-turns for thermal expansion, so I was surprised that the bearings only have about a centimeter of axial movement.
A lot of echo in the test cell, but a fantastic video as usual!
The blade count differs in the CFM-56s. The -2B, as used in the 135 fleet, have 44 fan blades. The more modern versions of the 56s usually have the nifty wide-chord blades that lead to a larger dia. fan with less blades that turn slower to meet the required standards for noise regs to allow carriers to fly into more airports.
I was curious if you could at some point do a video about airflow regulation in engines? VSVs/VBVs vs RCVVs, CIVVs and a bleed strap, etc. Thanks! Love the videos!
Another excelent vid Jay. Since ive been watching your vids, i see engine parts as props in sci-fi movies all the time now. e.g. STAR WARS a new hope: Centrifugal engine type intake screen in background of Luke's Tatooine house, ? a combuster can on shelf, stator section on the ground outside Mos Eisley cantina, double sided centrifugal compressor disk and and compressor manifold atttached to one of the manned cannons on the death star during the end battle scene. Keep up the good work.
@matube73 Also in Star Trek 2009, at about 1:25:00 there, in the engine room of the Enterprise, is a J79 afterburner fuel manifold ring, an LM2500 compressor case, and a stack of J47 combustor cans.
Cool that we work on all of those engines !
And in the pilot episode of Battlestar Galactica (2003 ?) in the maintenance bay there are several RR/Allison 250 turboshafts on rolling stands... That was shot in the old BCIT building where I trained on those exact engines.
But how do you assemble the turbine without smashing the stator blades into the rotor? I guess one half of the stator is about (hard to guess ^^) 25kg, thats some nice weight for precision placement without dangling around.
Thanks for the great videos! I found these a couple of days ago and I'm attempting to go through the entire playlist. You said that the shaft to drive the gear box and accessories was located at the third stage of the HPC. But it looks like the shaft to the accessory gear box on the diagram that I have (CFM 56-7B) passes between where the LPC and HPC are located. Then again, it is kind of hard to show on a 2D diagram a shaft which comes out of the page to a gear box on the side of the engine.
tvirus457 2 days ago in playlist Uploaded videos
@tvirus457 ... If I said it that way, it's wrong. The radial drive shaft would be driven by the HPC, and the most sensible place to do that would be from one end of it, and the cold end would be better than the hot end.
Your location is the right one.
AgentJayZ 2 days ago
Jay, why does the thrust bearing for the LM1500 come vacuum packed? Isn't it just another piece of metal like the rest of the engine which is always exposed to air? I was thinking maybe corrosion prevention?
343jonny 5 days ago
@343jonny It's not really vacuum packed, but it's packed in oil to prevent corrosion. The packaging is sealed to prevent leakage, and looks vacuum packed to use as little oil as possible.
AgentJayZ 5 days ago
the CFM56 is not on the A330........its on the A320 series and the early A340s
viperdriver82 3 weeks ago in playlist More videos from AgentJayZ
@viperdriver82 You're right! I couldn't reshoot the video, and I forgot to fix that mistake with annotations. I was wondering when I would be caught.
The reason I messed up : because the 330 is one of my favorite airliners. It looks like it giant bird that sticks its neck out far forward because it is so happy to fly.
AgentJayZ 3 weeks ago
I love these videos, but I cannot truly believe that that Lm 1500 bearing cost $20,000 with four zeros. I can buy a used Allison 250 for that.
highvoltagefeathers 3 weeks ago
@AgentJayZ I am a Jordanian Mechanical Engineer, I thank you very much for the very useful videos you produce, I searched a lot for a specialized information about gas turbine and jet engines for long time, and I didn't find any valuable thing, but discovering your channel was for me like discovering a treasure. THANK YOU and KEEP IT UP, I wish you best luck.
suhaybpro 1 month ago 2
@AgentJayZ thank you for your great videos!
theturbofantastic 1 month ago
@lazystart I think you are referring to the active clearance control system, which controls the clearance between the turbine blade tips and the turbine casing/liners. What is actually altered here is not the length of the blades, but the diameter of the casing, resulting in an optimal clearance and minimal loss of power. This is generally achieved by cooling the turbine casing outer face by means of air pipes with little holes in them, thus controlling the expansion of the turbine casing.
theturbofantastic 1 month ago
If I remember correctly from advanced troubleshooting class, another factor contributing to the CFM56's efficiency is a system that thermally expands/lengthen the compressor blades to minimize the gap between the blade tip and the casing, thus reducing the amount of wasted flow-by air. I'll go find my stack o' books to verify this.
lazystart 1 month ago
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
BACON STRIPS &
TheEPITROCHOID 2 months ago
@TheEPITROCHOID
... They didn't have an epitrochoid bacon strips one...
Bacon weave = win !
AgentJayZ 1 month ago
Thank you so much for taking the time to explain all this. This is amazing stuff
mparipari 2 months ago
Your stuff is fantastic! Thanks so much, I am impressed with your detail and well edited videos. All I can say is thank you.
thedulcimer 3 months ago
Wow I love your channel and is a really informative set of videos to help me with my growing love of jet engines. Could you help me with this question? How does the engine regulate the two systems (HP and LP) to run at different RPMs?
dklearjet 3 months ago in playlist More videos from AgentJayZ
Jay, i think i need help. I cant stop watching your videos dude! Awesome, very informative and interesting and your excellent at getting the information across without over complicating things. Thankyou for taking the time to make them, John.
xxJohn1977xx 3 months ago
A larger fanned variant of this engine (the TF41) was used in the A-7 Corsair II. The exposed first stage is one of the reasons it was referred to as a "maneater." Careful out there.
corrodesthefilm 3 months ago
This is one of the best videos you have posted.
ASSEMblerEX 4 months ago
Hey that rolls royce engine is similar to the Pratt and Whitney JT8D we have on school!! it is also a twin shaft turbine the only difference is that regardless it is also from stone age, the JT8D its a turbofan engine :P like the CFM 56 :)..
Just wanted to say that your videos are great and very helpful!!
greetings from mexico :D!!!
MonoBawuino 4 months ago
@MonoBawuino Dude... have some respect for the old school...
The JT8-D is the most-produced large turbine engine in history. The CFM56 is a fantastic, beautiful, efficient and wonderful machine, but it dreams in its wet dreams of ever being as successful as P&W's transitional masterpiece.
AgentJayZ 4 months ago
@AgentJayZ hahaha i know!! there are hundreds still flying some large MROs like ITR opened large facilities just specialized in that engine ... just was trying to point that the design that CFM 56 has is polished from engines like the JT8D who was a revolutionary engine at its time in terms of design and efficiency of the civilian jet industry :) i just pointed its age because thats amazing
MonoBawuino 4 months ago
@MonoBawuino The CFM56 is getting on 35 years old or so, and still a fully modern engine. It will be very interesting to see what the next step will be.
AgentJayZ 4 months ago
Is that a EpicMealTime shirt I see???
Bergstaller01 4 months ago
There's an industrial Trent test cell just down the street from me.
Bergstaller01 4 months ago
As interesting as ever....
One thing I was wondering (please forgive my lack of engineering knowledge), in a turbofan engine (like CFM56), does the gearbox take power from the high pressure or low pressure system?
Watching your video's has made me wish I did aeronautical engineering at university...... I ended up doing Business instead.
daniel2001 4 months ago
@daniel2001 You could think of the HP system as the essential engine, or the "core" engine... and that's what it is sometimes called. The LP system is mainly a way of harnessing the power of the HP system and using it more efficiently to propel the aircraft, and it also acts like a supercharger for the HP "core".
All of the accessories and power take-off devices take there power from the HP system.
The only thing running off the LP system is the LP speed sensor.
AgentJayZ 4 months ago
@AgentJayZ Ah cool. Thanks for taking the time to respond, and for taking the time to make your video's in the first place.
daniel2001 4 months ago
Mate your videos are awesome. Thankyou for taking the time to make them with such great depth.
xxJohn1977xx 4 months ago
Excellent video, I enjoy seeing the mechanical details that you do not see anywhere else!
kneecaps2000 4 months ago
You are a great teacher...I was shocked about that price, but it worth it though, thats ultra precision engineering!
prandtl002 4 months ago
So now that all these parts come together, is there a real-world simulation to see how each compressor stage acts on the air? e.g. by using different coloured air pass through the engine or something along those lines?
abhinav87 4 months ago
And since you pointed out that this is the place for nice and interesting details ;-) here is a minor correction:The CFM56 has never been installed on the A330, however it is a very common powerplant on the A320 series.
Furthermore these are missing numbers for blades/vanes installed on LPC/Booster
Stage1--> 24 blades/108 vanes (on older versions i.e. CFM56-3 also 38 up to 44 blades)
Stage2--> 74 blades / 136 vanes
Stage3--> 78 blades / ""
Stage4--> 74 blades / ""
Greetings from Germany
Jigme85 4 months ago
Heya AgentJayZ, I've been following your channel for a while now, I really wish this stuff would've been around when I started studying Aero.Eng., would have saved me a lot LOT of looong nights sitting in front of crazy diagrams trying to figure out how Gas Turbines actually work in detail.... but I still enjoy watching this channel a lot, so THANK YOU!
Jigme85 4 months ago
you no you have one of the cool job man it may take month's to Rebuild one but I still like you job and your a good teacher as well man
ISUZU1987 4 months ago
Great video as always and great shirt too. :)
mwiz100 4 months ago
@mwiz100 Hey, I'm a Canadian, and proud of what my fellow Canadians have done...
AgentJayZ 4 months ago
Excellent one, thanks!
pjvenda 4 months ago
Another great video mate. You would make a great teacher Jay.
topdoorslammer666 4 months ago
Great video as usual. I would like to see how those bearings are lubricated, i.e. the oil system.
hopper1 4 months ago
Very well illustrated. And thanks for the recommendation of that book "The Jet Engine". I go nuts when i see something that interests me and I don't know exactly how it works. Your videos answer many questions.
BigBoy4005 4 months ago
Another amazing video, really appreciate the detail, Thanks
DavoCitizen 4 months ago
Another great video. Thank you very much sir.
mobius1aic 4 months ago
9:34 $20,000!??! HOLY FUCKING CHRIST
Well it's worth it.......
mobius1aic 4 months ago
20k for a bearing hu? Thats starting to sound like my job, everything overpriced. I discovered one of our foot long liquid oxygen hoses costs $500, and it was not even insulated! BTW, like the shirt, marines love epic meal time, insane amounts of food....and JACK DANIEL'S, im a sigle barrel select drinker myself. Gotta go for the EXTRA good stuff. :)
JetAce08 4 months ago
Hi AgentJayZ, great video, thanks! Just one question, are there any thrust bearing near the nozzle of the engine? I understand that the compressors try to move forward by blowing air backwards, but the burning gas also try to push the turbines out of the nozzle. If there is no thrust bearing near the nozzle, does it mean that the engine is designed such that the force pushing the turbines backwards is definitely large than the force pushing the compressors forward?
crazyrum 4 months ago
@crazyrum The turbines are connected to the compressors. Typically for each shaft there needs to be three bearings: supporting radial loads at the front and rear, and one supporting the axial loads somewhere else.
The thrust bearing can be anywhere along the length of the shaft, as shown here by both of them being at the front of their shaft.
AgentJayZ 4 months ago
@AgentJayZ Ah, I see, the ball bearing can provide force that prevent the shaft from moving either forward or backward. Since at first it has the word "thrust" on only one side of the race, I thought it is only designed to withstand force from one direction along the axle
crazyrum 4 months ago
@crazyrum Ball bearings by their basic shape can handle axial loads in either direction. Thrust bearings are slightly modified, as shown in the video, to optimize their load carrying in one axial direction, but they still can handle both.
The load on the thrust bearing in a gas turbine engine changes in magnitude with power output, but it is always in the same direction.
AgentJayZ 4 months ago
Holy crap!!! A $20,000 bearing????? Are you serious?
oisiaa 4 months ago
The axial motion on the roller bearing is less than I would have thought. The external parts, like fuel tubing, seem to leave a lot of bends and U-turns for thermal expansion, so I was surprised that the bearings only have about a centimeter of axial movement.
A lot of echo in the test cell, but a fantastic video as usual!
sharrynuk 4 months ago
The blade count differs in the CFM-56s. The -2B, as used in the 135 fleet, have 44 fan blades. The more modern versions of the 56s usually have the nifty wide-chord blades that lead to a larger dia. fan with less blades that turn slower to meet the required standards for noise regs to allow carriers to fly into more airports.
I was curious if you could at some point do a video about airflow regulation in engines? VSVs/VBVs vs RCVVs, CIVVs and a bleed strap, etc. Thanks! Love the videos!
SmokedTails 4 months ago
Another excelent vid Jay. Since ive been watching your vids, i see engine parts as props in sci-fi movies all the time now. e.g. STAR WARS a new hope: Centrifugal engine type intake screen in background of Luke's Tatooine house, ? a combuster can on shelf, stator section on the ground outside Mos Eisley cantina, double sided centrifugal compressor disk and and compressor manifold atttached to one of the manned cannons on the death star during the end battle scene. Keep up the good work.
matube73 4 months ago
@matube73 Also in Star Trek 2009, at about 1:25:00 there, in the engine room of the Enterprise, is a J79 afterburner fuel manifold ring, an LM2500 compressor case, and a stack of J47 combustor cans.
Cool that we work on all of those engines !
And in the pilot episode of Battlestar Galactica (2003 ?) in the maintenance bay there are several RR/Allison 250 turboshafts on rolling stands... That was shot in the old BCIT building where I trained on those exact engines.
AgentJayZ 4 months ago
you have the coolest job ever!!! wish i could work there
xXSup399Xx 4 months ago
hi are u gonna run that engine?
carlosmax50 4 months ago
@carlosmax50 Soon...
AgentJayZ 4 months ago
I giggled at the thrust here label. Awesome video and nice diagrams.
nodariel 4 months ago
1170 blades * 15 minutes = 17550 minutes / 60 = 292.5 hours
saxonlight 4 months ago
@saxonlight
and that's not counting all the stators and EVERYTHING ELSE...
very impressive engineering
rchelimania 4 months ago
As always Jay,thank you so much for sharing! Great video! Can't wait to see more ;-)
WolfenGeist 4 months ago
Great video!
Very interesting to see how it really works and all the details.
Nice camera work...I love it.
This is better than going to school! :-)
Thanks
MusicMan20061210 4 months ago
I'd say that anything sucked in to that spey would completely destroy the blades of the compressor stages and atleast damage the turbine blades.
TheElectricnoob 4 months ago
Bacon Strips
Keskivertomies 4 months ago 2
Nice video again :D
But how do you assemble the turbine without smashing the stator blades into the rotor? I guess one half of the stator is about (hard to guess ^^) 25kg, thats some nice weight for precision placement without dangling around.
XTwina 4 months ago
Wow, $20k bearing.
sabamacx 4 months ago
Nicely explained. Bet a triple shaft engine would be far more complex.
FrontSideBus 4 months ago
nice video as usual.
nice because it is hard to find someone that takes the time to explain such interesting things!!!
thanks!
damio 4 months ago