I have retired from the military and am in the beginning stages of improving my knowledge, videos like this is exactly the type and style of information I have been hungering for. thank you very much
Hello Mr.Gey man, congrats on your retirement and thank you for your service. Thank you for your kind words. I appreciate it. Let me know of any other question or curiosity you have and if I'm able to shed some light, I'll try my best. Welcome to Plane Simple.
@@planesimple8514 Actually, there is something you might be able to help me with. I have been studying Henry Coanda's theory of thrust. With this in mind, could and axial centrifugal compressor be fitted to a small engine, say a rotary, to create enough air pressure to be able to create lift for a small VTOL craft? Think big or go home as my old R.S.M use to say.
Thanks for the video! I was recently looking at some display engines at our local air museum and couldn’t figure out why there was no direct air path on the older engines. Now I know that centrifugal flow engines exist, it not only answers that question, but also explains why early jet fighters didn’t always have direct intakes straight into the engines.
Awesome Flyboy207! I'm happy to hear that you got these answers from my video. That's very satisfying. It's also good to see people like you that are curious enough to expand on what they see at a museum. A lot of people's curiosity ends the moment they step out of the museum. To build a bit more on the "indirect" path of the intakes, yes, having air come in through the side's into a centrifugal compressor lends itself to side air intakes on the airframe, but there's more to consider. The number of engines is also a determining factor. If you have two engines like an F-15, F-18 or F-22, you can have the cockpit in the center of the airframe when viewed from the front and still have intakes that are mostly directly in front of the engines . However, if you have only one engine like a F-16 or a F-35, then you Have the cockpit more or less in front of the engine so you are obligated to offset the intake around the cockpit. In the case of the F-16 into one single large duct underneath, or in the case of the F-35 into two smaller inlets on either side of the cockpit.
I am learning about this in school right now. I have been in turbines for a month and I could not get my head around this. I watched this video and everything just clicked. Thank you so much for posting this, it really helped. Especially the PT6 that one has been throwing me.
Ah, ok. Thank you for the clarification. It should be obvious that although I am a bit knowledgeable, I am by no means an expert. I like to learn and share knowledge with other who are interested. Having said that, I am always open to corrections and lessons from any source so we can all get better at what we like. Thanks again.
My pleasure Mir Aqueel Ali, that's 9ne 9f the reasons I started this channel, to show a hands on view of aviation that most people don't get to see. Thank you for the nice comment.
Thank you so very much man! It really means a lot to see your positive encouragement. Send me any suggestions or questions you may have and I'll try my best to give you an answer.
Good at least got to see the compressors in actual I love it and these types of videos are very rare and actually people are not at all interested in working they are interested in songs and I get amused by that. Don't worry Mr engineer u would get a good number of reviews and views.
Thank you very much. I really appreciate it. I am lucky to work in a field that I love. I realize that I am exposed to a lot of cool things that a lot of people are interested in and have questions about. I know that there's a lot of other sources for this kind of information, but I wanted to add my a piece from my perspective. Thanks you for the positive words.
G day hey ah thank you very much sharing your videos with us the viewers very enjoyable eh ,understandable , educational and interested , you always learn something from time to time , you described in plain English with camera and your hand pointing around to a specific spot , amazing , its make it more easy to understand so , good on you , thank you very much for this great sharing , beautiful , cheers
Amazing buddy. We never get to see real jet stuffs with our own eyes. All I saw was animation till now. You did an awesome job bro. Would be eagerly waiting for full scale teardown and rebuild of both centrifugal and axial compressor jet engine. Keep them coming 🤟
Thank you very much man. I really appreciate it. Sadly I don't do engine teardowns. All those on my video are training aids at school. And although we did do partial removals and assembly of certain sections, it was never very extensive, and during class so I could not film it.
@@planesimple8514 No worries brother. Just make sure to share even a bit of hands on stuff kinda things. I'm sure you will gain a lot of respect and viewers too. Enjoy your day🤟
Are compressors connected to a single shaft when axial and centrifugal are used in an engine or they rotate independent of one another?? How does the rpm look like in this combination? Is it N1 and N2 or just a tachometer? Thank you very much for your video and for your response in advance.
The compressors on small engines are typically on a single shaft [single spool]. Twin spool designs typically provide for a separate low pressure compressor and a high pressure compressor are more costly but offer higher performance. The HP comp operates at higher speed. We have a superior, low cost, higher performance architecture.
Thank you so much for the visualization and the explanation. I am preparing for my technical interview for the airline about Free turbines and etc. It helped a lot.
Thank you very much Leston. That means a lot. That's the reason I started this channel, to have a place for simple to understand bits of information for those who want it. Thanks again for the encouraging comment.
It seems that centrifugal compressor engines continue to be favoured for stationary or relatively slow moving applications such as helicopters, so in early jet powered aircraft (before the advent of turbofan engines) they were favoured. The larger diameter of these engines might present an obstruction to airflow 6:35 & thus a disadvantage within the duct of a turbofan? It is a pity that there is background buzzing noise in this interesting & informative video.
The 'backward' PT-6 jet turboprop engine is probably the most reliable engine on earth! I'd rather fly in any airplane with one of those than two of any other kind of engine. It's an excellent reliable efficient engine! AWESOME VIDEO! ❤❤❤
Hello D, sorry for the slow response. Yes, that type of engine has been used in turbojet applications. Look up the Lockheed T33 jet trainer with the Allison J33. That's one example.
Looking at the single stage centrifugal compressor on the first engine you showed us, what would you estimate the diameter of the compressor wheel is? What is the motor and who made it?
Hello earlyhemibill, that's a display cutaway modelI at Broward College. I couldn't find a data tag on the engine but I think it's an Allison J33. As far as the diameter of the rotor, I haven't been back there again to measure it exactly, but it should be just over two(2) feet.
@@planesimple8514 I'm building a motor now that I hope will propel a model airplane. It will use a 3200kv brushless motor with a 22.2 volt battery turning a 3.38" diameter turbo compressor wheel. It will turn at 71,000 rpm and feed a combustion chamber with methanol and exiting out a 1.25" tailpipe. My curiosity about the jet engine was to figure out how much velocity a real centrifugal compressor turns.
@@planesimple8514 No problem. I’m studying ATPL engines and like I said before you did a good job with this video. I found it simple, useful and very clearly. I will check for other your video on the channel! 👍🏼
very good presentation ...... it is still confusing the propeller engine air movement is opposite direction !!! whether this type of engines are using in C130 aircraft. we need more videos.....
Hello sajiktm, thank you for the comment. I'm not sure I understand your confusion or what you mean by "propeller engine air movement is opposite direction". As far as needing more videos, I should be releasing another video later today where we take an in depth look into a jet engine. I hope you like it.
Just seen your like mate. It’s ok it was just a mis understanding. I thought it was something more complex. They were just referring to the fact that nearer to the intake of the engine, the pressure is of course lower, and as it progresses further , increases
Hello Harry, thank you so much for the positive feedback and sorry I took so long to reply to your question. The low pressure vs. high pressure compressors refer to dual or triple spool turbine engines. That means that there are two or three concentric shafts running one inside the other. In the case of a triple spool engine, the inner most shaft connects the last stages of the turbines at the back of the engine to -usually- the big bypass fan in the front of the engine. This shaft runs right through the very center of the engine from end to end. Around that inner most shaft is an intermediate (hollow) shaft that now connects the "low" pressure turbine to the "low" pressure compressor. This secondary assembly spins or spools independently from the first shaft and therefore can spin at different speeds. This "low" pressure assembly compresses the intake air up to a point, after which the compressor would have to be spinning much faster in order to compress it any higher, but if you spun this entire assembly faster, then the air speed of the incoming air would not be enough for proper flow. That's where the "high"pressure compressor comes in. It is yet one more shaft/compressor/turbine assembly free to spin at its own speed independent from everybody else. This time, the "high" pressure turbines power the "high" pressure compressor at a much faster speed in order to achieve the high pressures of modern engines, but yet allow the "low" pressure assembly to rotate at its optimum RPMs, as well as spinning the bypass fan up front at yet an even slower speed. It is all in the name of efficiency and having the ability to spin different parts of the engine at the optimum RPMs for their functions, at the cost of adding mechanical complexity of course. I know this was a long answer but I hope it makes sense. Cheers.
This sounds complicated but at least in principle, the concept of it is not as hard. It's just hard to explain in a short text. May I recommend videos by "AgentJZ", he has a few videos explaining this very concept and are an excellent source of knowledge.
@@planesimple8514 awesome thanks for that mate, see maybe I missed it in the video but I didn’t realize there were multiple turbines in the aft end of the engine and multiple spools turning at different speeds (low and high). I thought it was all one shaft, but (instead of multiple spools at different rpm) the angle of the compressor rotors changed. But now I think about it, if it were like that, they would clash and restrict each other to to an extent. (in terms of them wanting to operate at different speeds) Let me know if I’m talking rubbish mate haha Also so when people say ‘three stage compressor’ (for example) they are referring to the number of spools
Hello Harry, I have made a new video trying to answer your question in a more complete way. I hope it adds a little more clarity on the subject. And if you do see it, I recommend you take a minute to read a comment from "Laertes L" about the video. He added a couple of corrections that are helpful too. Cheers.
I'm not sure exactly, but for the axial compressors, I think the discs that support the blades are steel and the blades themselves are titanium(when you grind them the sparks are white). And I think on the axial compressors the impeller might be aluminium, because it's so massive that it can be a softer metal. That would be my guess.
Hey bro, thanks for the walk through. Check out SpaceX rocket engines. They are starting to look like turbines with centrifugal compressor on an axial design.
HOLLY CR@P..!!! I DID...!!! I TOTALLY DID...!!! 😂😂 I never noticed that!!! And neither had anyone else. You are the first to point that out!! My apologies for the unprofessionalism of that burb, but it went TOTALLY unnoticed. Good job picking up on it. That means you were really paying attention. Thank you and welcome to Plane Simple, where you can hang out in the shop ...and burp 😜
No problem. If you want to see an example of how that HOT air is used for in the aircraft (other than producing thrust) you can see a video I did a while back that looks at wing Anti-Ice system. There you can see the piping taking that "bleed air" away from the engine compressor and uses it to warm up the wing's leading edge.
The first engine with the blue blades is a centifugal 'flow' engine. Think of airflow. The air compression and movement is caused by centrifugal force. Like a washing machine spinning to get the water out of clothing. The air is flung outward by the blue turbine, that compressed air moves around and into the yellow 'burner' cans (combusters) where the fuel is injected inside the cans. The burn creates hot expanding gas that moves thru and against the 'tubine' (exhaust) wheel blades. They are fixed to the shaft which turns the centrifugal compressor at the front. Centrifugal flow engines didn't last very long. They were quickly outdated by the invention of the Axial Flow Jet Engine. Axial Air Flow is accomplished with multiple sets of compressor blades lined up on the center axis (the long shaft) of the engine. The air moves along the center axis. Axial Flow ! It moves to the burner section aligned with the center axis, keeps moving straight back to the (exhaust) turbine blade(s) which turns the center (axial oriented) shaft which turns the compressor blades. The whole system aligns front to rear aligned with the Center Axis of the engine. Axial airFlow Jet Engine !
Hello FlipFliop, no, the axial part of the compressor is not to avoid compressor stall, it is to compress the air before being compressed further in the centrifugal section. You could either have a single stage centrifugal compressor, like the big, double sided, one stage compressor in the video. You could have a two stage centrifugal compressor where one stage feeds the other. You could have an axial compressor alone, with more stages for higher compression like the one in the turbojet from this video, or you could have a combination of both, and that's what you have in the P&W PT6 which is the turboprop you refer to in this video. Therefore, the axial section of the compressor is not to avoid compressor stall, it's function is like it's name implies, to compress the air. I hope that was easy to understand and clarifies any questions.
@@planesimple8514 Thank's for your explanation sir. But, I mean the axial parts is like giving constant air feed and pressure to the single stage centrifugal side to compensate rapid ambient air/ pressure, air direction change while flying. I hope you get what i mean bcoz it's difficult for me to express it in english :-).
No worries, english is also my second language so I understand. Actually, a centrifugal impeller is less likely to stall if it stalls at all because it does not depend on an air foil shape to move the air and therefore does not a critical angle of attack. It is more like paddles mechanically pushing the air. An axial compressor on the other hand, is nothing more than a collection of tiny little wings with air foil profiles that much like a wing pushes air down to create lift, the blades(little wings) on an axial compressor push air back into the compressor where it is compressed further at each stage. Now, just like an aircraft wing stalls when the angle of attack is too great, so do the axial compressor blades. If the air speed is too little for the compressor speed, then you could get a compressor stall. I know this has been a long answer, but going back to what I said in the beginning, an axial compressor is more likely to stall than the centrifugal one, and the function on the axial compressor, is just to compress the air, and the centrifugal stage is a final kick to further compress that air. I hope this makes sense and it helped you.
@@planesimple8514 I appreciate your effort explaining those stuff to me and it helped me a lot. Thank You Look forward how many miles this channel would go from your 53rd Subscriber
There is a continuous high tone in the vid so I stopped watching. But my question is: It is an air compression system right? Takes air from outside and that is the 'fuel'?
Hello hongry life, there's nothing I can do about the background noise and I don't have the tools or skills to remove it in post edit, since I mostly do not edit the videos. To answer your question, NO, the air is not the fuel. The fuel is the fuel, the Jet Fuel is the source of energy that needs air to burn with, to heat up and expand so it can do work. The air is the source of oxygen to burn the fuel with. Recap: The fuel is the fuel(source of energy) Air is the oxidizer(source of oxygen to burn the fuel with) I hope this helps.
@@planesimple8514 Thanks for answering :) Do you know why the air has to be compressed immensely with the many circling/spiraling blades and the oxygen cannot be taken out of the air without that compression?
The point of burning the fuel is to produce heat. Compressing the air allows you to produce a lot more heat. As an example, a wax candle will burn and produce a little bit of heat. What determines the rate at which the candle will burn is the oxygen available around it to burn the wax(fuel) with. That candle will burn at whatever rate the oxygen in the surrounding air will allow. Now take that candle and feed it more oxygen, (air under pressure or compressed), now the candle is not limited by the available oxygen in the atmosphere, and now the same candle will turn into a raging fire that will consume the wax in a lot less time and it will produce A LOT more heat. The same goes for any fuel. Take a cup of jet fuel, light it, and you will get the equivalent of a candle, a slow flame that will waft a bit of heat. Take that same jet fuel, and feed into a jet engine that is supplying highly compressed air and that fuel now has a hell of a lot more oxygen to burn with and it will burn like a raging fire that produces a lot more heat to do more work. In short, the fuel will burn in regular uncompressed air but at a much slower rate and won't have the ability to do a lot of work like make planes fly.
We'll, I believe those care lights in the background. There's nothing I can do about them. Welcome to the world of aviation maintenance. It's a noisy one! Thank you for watching though.
I have retired from the military and am in the beginning stages of improving my knowledge, videos like this is exactly the type and style of information I have been hungering for. thank you very much
Hello Mr.Gey man, congrats on your retirement and thank you for your service.
Thank you for your kind words. I appreciate it.
Let me know of any other question or curiosity you have and if I'm able to shed some light, I'll try my best.
Welcome to Plane Simple.
@@planesimple8514 Actually, there is something you might be able to help me with. I have been studying Henry Coanda's theory of thrust.
With this in mind, could and axial centrifugal compressor be fitted to a small engine, say a rotary, to create enough air pressure to be able to create lift for a small VTOL craft?
Think big or go home as my old R.S.M use to say.
Thanks for the video! I was recently looking at some display engines at our local air museum and couldn’t figure out why there was no direct air path on the older engines. Now I know that centrifugal flow engines exist, it not only answers that question, but also explains why early jet fighters didn’t always have direct intakes straight into the engines.
Awesome Flyboy207! I'm happy to hear that you got these answers from my video. That's very satisfying.
It's also good to see people like you that are curious enough to expand on what they see at a museum. A lot of people's curiosity ends the moment they step out of the museum.
To build a bit more on the "indirect" path of the intakes, yes, having air come in through the side's into a centrifugal compressor lends itself to side air intakes on the airframe, but there's more to consider.
The number of engines is also a determining factor. If you have two engines like an F-15, F-18 or F-22, you can have the cockpit in the center of the airframe when viewed from the front and still have intakes that are mostly directly in front of the engines . However, if you have only one engine like a F-16 or a F-35, then you
Have the cockpit more or less in front of the engine so you are obligated to offset the intake around the cockpit. In the case of the F-16 into one single large duct underneath, or in the case of the F-35 into two smaller inlets on either side of the cockpit.
Very cool
Thanks for sharing this
My pleasure. I'm glad you liked it.
Dude, very informative, quick and easy to digest information and with model diagrams, great job!
Thank you Mike Burrello. I appreciate it.
Great video. Cheers from a Once-pioneer, Argentina.
@sebastiandc, hola Argentina 🇦🇷...!!!
Gracias.
Saludos desde el hemisferio norte.
I am learning about this in school right now. I have been in turbines for a month and I could not get my head around this. I watched this video and everything just clicked. Thank you so much for posting this, it really helped. Especially the PT6 that one has been throwing me.
That's awesome to hear! Thank you very much Travis Bratton and good luck in school.
Great Video, PT-6 is a reverse flow because it reverse flow in the Combustion chamber not because its mounted backwards
Ah, ok. Thank you for the clarification.
It should be obvious that although I am a bit knowledgeable, I am by no means an expert. I like to learn and share knowledge with other who are interested.
Having said that, I am always open to corrections and lessons from any source so we can all get better at what we like.
Thanks again.
Thanks a lot for showing actual models
My pleasure Mir Aqueel Ali, that's 9ne 9f the reasons I started this channel, to show a hands on view of aviation that most people don't get to see.
Thank you for the nice comment.
Sir, this is an amazing video, thank you. Good bless u. The universities , text books and the professor's have made a mess of this concept
Wow! Thank you very much! Comments like yours are what inspire me to make these videos. Thank you again.
Man at Last a good teacher thank you so much plz make these kind of videos 😭❤️
Thank you so very much man! It really means a lot to see your positive encouragement. Send me any suggestions or questions you may have and I'll try my best to give you an answer.
Good at least got to see the compressors in actual I love it and these types of videos are very rare and actually people are not at all interested in working they are interested in songs and I get amused by that. Don't worry Mr engineer u would get a good number of reviews and views.
Thank you very much. I really appreciate it. I am lucky to work in a field that I love. I realize that I am exposed to a lot of cool things that a lot of people are interested in and have questions about. I know that there's a lot of other sources for this kind of information, but I wanted to add my a piece from my perspective. Thanks you for the positive words.
G day hey ah thank you very much sharing your videos with us the viewers very enjoyable eh ,understandable , educational and interested , you always learn something from time to time , you described in plain English with camera and your hand pointing around to a specific spot , amazing , its make it more easy to understand so , good on you , thank you very much for this great sharing , beautiful , cheers
Hello Sione Kulu. Thank you very much for the kind words, they mean a lot.
Probably the best explanations. THANK YOU very much :)
Thank you!
astonished by such clear explanation! didn't think understanding this concept will be this easy....thank you so much sir!
Wow! Thank you very much for such a positive comment. I'm glad my video helped you and was easy to understand.
Amazing buddy. We never get to see real jet stuffs with our own eyes. All I saw was animation till now. You did an awesome job bro. Would be eagerly waiting for full scale teardown and rebuild of both centrifugal and axial compressor jet engine. Keep them coming 🤟
Thank you very much man. I really appreciate it. Sadly I don't do engine teardowns. All those on my video are training aids at school. And although we did do partial removals and assembly of certain sections, it was never very extensive, and during class so I could not film it.
@@planesimple8514
No worries brother. Just make sure to share even a bit of hands on stuff kinda things. I'm sure you will gain a lot of respect and viewers too. Enjoy your day🤟
Thank you very much. You too.
@@planesimple8514
10-4
That’s how some turbo props have weird yet simply placed exhaust! How have I never looked into this
Yes, it's counter intuitive to see those exhausts seemingly placed in random places, but it makes sense once you know why that is.
Gas turbine electrician. Great information and most importantly accurate
Thank you very much William Blankenship, that really means a lot!
Are compressors connected to a single shaft when axial and centrifugal are used in an engine or they rotate independent of one another??
How does the rpm look like in this combination?
Is it N1 and N2 or just a tachometer?
Thank you very much for your video and for your response in advance.
The compressors on small engines are typically on a single shaft [single spool]. Twin spool designs typically provide for a separate low pressure compressor and a high pressure compressor are more costly but offer higher performance. The HP comp operates at higher speed.
We have a superior, low cost, higher performance architecture.
Excellent video and explanation. Thanks
Thank you very much Rodrigo, I appreciate it.
appreciate you Mr. engineer
Thank you
Thank you so much for the visualization and the explanation. I am preparing for my technical interview for the airline about Free turbines and etc. It helped a lot.
My pleasure. Good luck in the interview.
Great video
Glad you enjoyed it
Nice explanation. Concise and very helpful
Thank you very much Leston. That means a lot. That's the reason I started this channel, to have a place for simple to understand bits of information for those who want it. Thanks again for the encouraging comment.
Wonderful explanation. Thank you!
Thank you Victoria Victoria, glad you liked it.
It seems that centrifugal compressor engines continue to be favoured for stationary or relatively slow moving applications such as helicopters, so in early jet powered aircraft (before the advent of turbofan engines) they were favoured. The larger diameter of these engines might present an obstruction to airflow 6:35 & thus a disadvantage within the duct of a turbofan?
It is a pity that there is background buzzing noise in this interesting & informative video.
The 'backward' PT-6 jet turboprop engine is probably the most reliable engine on earth! I'd rather fly in any airplane with one of those than two of any other kind of engine. It's an excellent reliable efficient engine! AWESOME VIDEO! ❤❤❤
Great info ℹ️
New mechanic here, amazingggggg break down (: Thanks for this
My pleasure. Thank you for such nice feedback! I appreciate it.
has the first example - the centrifugal-compressor jet engine - been used on aircraft as a turbojet, or is it more used as a turboshaft engine?
Hello D, sorry for the slow response.
Yes, that type of engine has been used in turbojet applications. Look up the Lockheed T33 jet trainer with the Allison J33. That's one example.
Also, Grumman F9F Panther. An early Navy Jet Fighter.
Looking at the single stage centrifugal compressor on the first engine you showed us, what would you estimate the diameter of the compressor wheel is? What is the motor and who made it?
Hello earlyhemibill, that's a display cutaway modelI at Broward College. I couldn't find a data tag on the engine but I think it's an Allison J33. As far as the diameter of the rotor, I haven't been back there again to measure it exactly, but it should be just over two(2) feet.
By the way, "earlyhemibill" is a great name!
@@planesimple8514 They are one of my hobbies.
That's awesome! Enjoy it and happy new year.
@@planesimple8514 I'm building a motor now that I hope will propel a model airplane. It will use a 3200kv brushless motor with a 22.2 volt battery turning a 3.38" diameter turbo compressor wheel. It will turn at 71,000 rpm and feed a combustion chamber with methanol and exiting out a 1.25" tailpipe. My curiosity about the jet engine was to figure out how much velocity a real centrifugal compressor turns.
Very good explanation! Good job!
Hello Federico, thanks for taking the time to leave a comment and for the positive feedback. I appreciate it.
@@planesimple8514 No problem. I’m studying ATPL engines and like I said before you did a good job with this video. I found it simple, useful and very clearly. I will check for other your video on the channel! 👍🏼
Thanks 😊 I love jet engines pretty cool
Thank you, I'm glad you liked it. I think they are fascinating too!
very good !
Thank you
very good presentation ...... it is still confusing the propeller engine air movement is opposite direction !!! whether this type of engines are using in C130 aircraft. we need more videos.....
Hello sajiktm, thank you for the comment.
I'm not sure I understand your confusion or what you mean by "propeller engine air movement is opposite direction".
As far as needing more videos, I should be releasing another video later today where we take an in depth look into a jet engine. I hope you like it.
Thanks a lot for the video,,,,
Thank you Cosmic Detective.
I like your name.
Very good mate I like how you explain👍 would you be able to explain about what people call the ‘high’ and ‘low’ pressure compressors ?! Thanks a lot
Just seen your like mate. It’s ok it was just a mis understanding. I thought it was something more complex. They were just referring to the fact that nearer to the intake of the engine, the pressure is of course lower, and as it progresses further , increases
Hello Harry, thank you so much for the positive feedback and sorry I took so long to reply to your question.
The low pressure vs. high pressure compressors refer to dual or triple spool turbine engines. That means that there are two or three concentric shafts running one inside the other. In the case of a triple spool engine, the inner most shaft connects the last stages of the turbines at the back of the engine to -usually- the big bypass fan in the front of the engine. This shaft runs right through the very center of the engine from end to end. Around that inner most shaft is an intermediate (hollow) shaft that now connects the "low" pressure turbine to the "low" pressure compressor. This secondary assembly spins or spools independently from the first shaft and therefore can spin at different speeds. This "low" pressure assembly compresses the intake air up to a point, after which the compressor would have to be spinning much faster in order to compress it any higher, but if you spun this entire assembly faster, then the air speed of the incoming air would not be enough for proper flow. That's where the "high"pressure compressor comes in. It is yet one more shaft/compressor/turbine assembly free to spin at its own speed independent from everybody else. This time, the "high" pressure turbines power the "high" pressure compressor at a much faster speed in order to achieve the high pressures of modern engines, but yet allow the "low" pressure assembly to rotate at its optimum RPMs, as well as spinning the bypass fan up front at yet an even slower speed. It is all in the name of efficiency and having the ability to spin different parts of the engine at the optimum RPMs for their functions, at the cost of adding mechanical complexity of course.
I know this was a long answer but I hope it makes sense.
Cheers.
This sounds complicated but at least in principle, the concept of it is not as hard. It's just hard to explain in a short text. May I recommend videos by "AgentJZ", he has a few videos explaining this very concept and are an excellent source of knowledge.
@@planesimple8514 awesome thanks for that mate, see maybe I missed it in the video but I didn’t realize there were multiple turbines in the aft end of the engine and multiple spools turning at different speeds (low and high).
I thought it was all one shaft, but (instead of multiple spools at different rpm) the angle of the compressor rotors changed.
But now I think about it, if it were like that, they would clash and restrict each other to to an extent. (in terms of them wanting to operate at different speeds)
Let me know if I’m talking rubbish mate haha
Also so when people say ‘three stage compressor’ (for example) they are referring to the number of spools
Hello Harry, I have made a new video trying to answer your question in a more complete way. I hope it adds a little more clarity on the subject. And if you do see it, I recommend you take a minute to read a comment from "Laertes L" about the video. He added a couple of corrections that are helpful too.
Cheers.
Thank you
My question is :what is the material of these compressors ??
Titanium ,steel ..????
I'm not sure exactly, but for the axial compressors, I think the discs that support the blades are steel and the blades themselves are titanium(when you grind them the sparks are white). And I think on the axial compressors the impeller might be aluminium, because it's so massive that it can be a softer metal. That would be my guess.
Hey bro, thanks for the walk through.
Check out SpaceX rocket engines. They are starting to look like turbines with centrifugal compressor on an axial design.
جميل جدا
Thank you Mustafa Abbas
never seen a dual sided centrifugal. that's like frank whittle's original patent design?
Did you pause and burp at 4m42s? I hope that's what I heard because it made me laugh. A lot. P.S. Thanks for the video; very educational.
HOLLY CR@P..!!! I DID...!!! I TOTALLY DID...!!! 😂😂
I never noticed that!!! And neither had anyone else.
You are the first to point that out!!
My apologies for the unprofessionalism of that burb, but it went TOTALLY unnoticed.
Good job picking up on it. That means you were really paying attention.
Thank you and welcome to Plane Simple, where you can hang out in the shop ...and burp 😜
@@planesimple8514 Try farting in one of your future videos. See if you get away with that too.
I got a real buzz from that.
Thank you. I'm glad you liked it.
10/10 video
Thanks Charlie Smith, much appreciated.
Does the compressor heating the air?
Yes it does, a lot!
@@planesimple8514 thank You
No problem. If you want to see an example of how that HOT air is used for in the aircraft (other than producing thrust) you can see a video I did a while back that looks at wing Anti-Ice system. There you can see the piping taking that "bleed air" away from the engine compressor and uses it to warm up the wing's leading edge.
Is it axial or centrifugal compressor the first one
The first compressor in the video is an axial one.
The first engine with the blue blades is a centifugal 'flow' engine. Think of airflow. The air compression and movement is caused by centrifugal force. Like a washing machine spinning to get the water out of clothing. The air is flung outward by the blue turbine, that compressed air moves around and into the yellow 'burner' cans (combusters) where the fuel is injected inside the cans. The burn creates hot expanding gas that moves thru and against the 'tubine' (exhaust) wheel blades. They are fixed to the shaft which turns the centrifugal compressor at the front.
Centrifugal flow engines didn't last very long. They were quickly outdated by the invention of the Axial Flow Jet Engine.
Axial Air Flow is accomplished with multiple sets of compressor blades lined up on the center axis (the long shaft) of the engine. The air moves along the center axis. Axial Flow ! It moves to the burner section aligned with the center axis, keeps moving straight back to the (exhaust) turbine blade(s) which turns the center (axial oriented) shaft which turns the compressor blades. The whole system aligns front to rear aligned with the Center Axis of the engine. Axial airFlow Jet Engine !
Thanks I love it
Thank you jsi jsi.
On the last turboprop turbine, from your explanation I conclude that the function of axial part is to prevent the compressor from stalling. CMIIW
Hello FlipFliop, no, the axial part of the compressor is not to avoid compressor stall, it is to compress the air before being compressed further in the centrifugal section. You could either have a single stage centrifugal compressor, like the big, double sided, one stage compressor in the video. You could have a two stage centrifugal compressor where one stage feeds the other. You could have an axial compressor alone, with more stages for higher compression like the one in the turbojet from this video, or you could have a combination of both, and that's what you have in the P&W PT6 which is the turboprop you refer to in this video. Therefore, the axial section of the compressor is not to avoid compressor stall, it's function is like it's name implies, to compress the air.
I hope that was easy to understand and clarifies any questions.
@@planesimple8514 Thank's for your explanation sir. But, I mean the axial parts is like giving constant air feed and pressure to the single stage centrifugal side to compensate rapid ambient air/ pressure, air direction change while flying. I hope you get what i mean bcoz it's difficult for me to express it in english :-).
No worries, english is also my second language so I understand.
Actually, a centrifugal impeller is less likely to stall if it stalls at all because it does not depend on an air foil shape to move the air and therefore does not a critical angle of attack. It is more like paddles mechanically pushing the air. An axial compressor on the other hand, is nothing more than a collection of tiny little wings with air foil profiles that much like a wing pushes air down to create lift, the blades(little wings) on an axial compressor push air back into the compressor where it is compressed further at each stage. Now, just like an aircraft wing stalls when the angle of attack is too great, so do the axial compressor blades. If the air speed is too little for the compressor speed, then you could get a compressor stall. I know this has been a long answer, but going back to what I said in the beginning, an axial compressor is more likely to stall than the centrifugal one, and the function on the axial compressor, is just to compress the air, and the centrifugal stage is a final kick to further compress that air.
I hope this makes sense and it helped you.
@@planesimple8514 I appreciate your effort explaining those stuff to me and it helped me a lot. Thank You
Look forward how many miles this channel would go from your 53rd Subscriber
Thank you very much! Any time.
1:15 😁👌 = 🔒
I got a real Buzz out of this video.
Yeah... Sorry for the background noise. The lights in the shop are very noisy.
There is a continuous high tone in the vid so I stopped watching.
But my question is: It is an air compression system right? Takes air from outside and that is the 'fuel'?
Hello hongry life, there's nothing I can do about the background noise and I don't have the tools or skills to remove it in post edit, since I mostly do not edit the videos.
To answer your question, NO, the air is not the fuel. The fuel is the fuel, the Jet Fuel is the source of energy that needs air to burn with, to heat up and expand so it can do work.
The air is the source of oxygen to burn the fuel with.
Recap:
The fuel is the fuel(source of energy)
Air is the oxidizer(source of oxygen to burn the fuel with)
I hope this helps.
@@planesimple8514 Thanks for answering :)
Do you know why the air has to be compressed immensely with the many circling/spiraling blades and the oxygen cannot be taken out of the air without that compression?
The point of burning the fuel is to produce heat. Compressing the air allows you to produce a lot more heat.
As an example, a wax candle will burn and produce a little bit of heat. What determines the rate at which the candle will burn is the oxygen available around it to burn the wax(fuel) with. That candle will burn at whatever rate the oxygen in the surrounding air will allow.
Now take that candle and feed it more oxygen, (air under pressure or compressed), now the candle is not limited by the available oxygen in the atmosphere, and now the same candle will turn into a raging fire that will consume the wax in a lot less time and it will produce A LOT more heat.
The same goes for any fuel. Take a cup of jet fuel, light it, and you will get the equivalent of a candle, a slow flame that will waft a bit of heat. Take that same jet fuel, and feed into a jet engine that is supplying highly compressed air and that fuel now has a hell of a lot more oxygen to burn with and it will burn like a raging fire that produces a lot more heat to do more work.
In short, the fuel will burn in regular uncompressed air but at a much slower rate and won't have the ability to do a lot of work like make planes fly.
Change the light balast!
I learnt in just 7 minutes ...but my sir taken to teach 2 hours
Hello SHREESHAIL, welcome to PLANE SIMPLE. I'm glad you understood my video. Thank you for taking the time to leave a comment.
ممكن ترجمه عربي
Yes, thanks to the magic of Google Lens, I can translate Arabic.
I'll reply in English though.
@@planesimple8514 Very well
❤️. 🇮🇳
Hello jos. Greetings to India!
Хорошо порезано
That buzzing is unbearable
We'll, I believe those care lights in the background. There's nothing I can do about them. Welcome to the world of aviation maintenance. It's a noisy one! Thank you for watching though.