I am a diesel engine mechanic by trade and vintage Canadian aircraft buff, with specific interest in the CF-100. .I love your non technical way of explaining how things work so that anyone can understand . You have certainly helped me understand the workings of a gas turbine engine better then any text book could. I'm so happy to have found your channel. Please keep up the great work!
@@AgentJayZ I think there is a Mark5 sitting in the Heritage Museum in Hamilton Ontario that could use a pair if 11's should they every choose to take it to flight status. It really is a shame that there is not at least one of these beautiful birds preserved in flying condition.
"36.000 rpm ... yeah ... the starter motor is not gonna like that" XD had me rolling. Thanks for showing us the real parts moving. Diagrams are nice but seeing it "in action" is so much more explanatory.
Agent Jay Z, I spent 12 years as a mill/turn machinist at an aerospace MRO facility, and the “ratchet wheels”, and the pawl carrier housings were a common job that I routinely ran. Thanks for the assembly breakdown… nice to see how these components are actually assembled and function!
@ No sir. These were OEM spec parts that we manufactured, via licensing agreement. All parts we made in house, except for the actual pawls, which were procured from a forging plant, then final machined to meet the requirements for application.
"We're gonna see debris rapidly exiting the scene..." That's a beautiful description LOL 🤣🤣🤣 Excellent explanation on this connector!! I do love it when true mechanics go in-depth on seemingly (to a layman) incomprehensible machinery... My dad was a lifelong mechanic, or an 'oily rag', since he was 17 until he passed away at 61 in 1999, and he so would've loved these videos... His passion for engines sort of affected me obviously 😎👍
Thanks for posting! very interesting. Fun fact: in smaller helicopter turboshaft engines like the Safran Arriel or PWC PW207 the starter is also the electrical generator and it is permanently coupled to the gas generator main shaft (through a gear reduction).
That is what I assumed of to be the case in most engines - that you would use the starter motor as a generator. But then I saw some APU diagrams where starter and generator were to seperate units with very different configurations.
When I was a crew chief on B-52s and ran engines for ground tests, were taught to keep our finger on the starter switch (8 starter switches on a B-52) for the engine we were starting so we would not forget to turn the switch off at 40% to avoid ovetspeeding the starter.
my favorite part about gt mechanics is that we all understand the engine from a perspective that doesn't require complex nomenclature. we KNOW it, we just don't need it to explain how this works. "gear type thing" is perfectly sufficient
I love it. I thought the clacking on spin-down was due to the lose blades shifting when there wasn't any centripetal force holding them in fixed locations at their roots. Thanks.
The starter ratchet reminds me of a recoil type rope starter on a lawn mower engine. How it engages and disengages are similar. Only it’s the inverse. The recoil starter engages the teeth in the gear attached to the engine crank shaft. And it releases when the rope is pulled no longer being pulled.
In the automotive transmission world, we call them Sprag clutches Look up the one for a chevy turbo 400 reverse sprag. Granted, the planetary is not integral to the unit but the sprag is a pretty cool little one way clutch.
I 'd like to share with you a bit of jet engine history. I've just been watching a TV documentary about the winter of 1947 in the UK, when we had snow on the ground for over seven weeks, which I think I can just remember. So what has this got to do with jet engine history, you may ask? Well, there was a brief clip of two Whittle-style jet engines with reverse-flow combustion chambers (they were probably R-R Wellands) mounted on a railway truck, being used as snow blowers to clear the track.
G'day Jay, Every Heligoflopter has a similar setup, between Powerplant and Main Reduction Gearbox, so that if the Fire blows out - then the Main Rotor, by Autorotating..., is able to drive the Tail-Rotor's Driveshaft via the Main Re-Drive Gearox. Also, pretty much every Small Engine featuring a "Spring Recoil" Starter Pulley, has a simplificated low-budget Plasticised version of what is "Officially" termed a, "Spring-assisted Centrifugal-Sprag type Clutch", otherwise colliquially termed a "Borg-Warner Clutch"...; presumably named after the Inventor, or they who first took it to market...(?). Maybe the Writers of the Jet Engine Textbooks assumed that anybody aspiring to tweak Spanners on a Turbine Engine..., would have, previously at some point, pulled apart A Pullstart From a Lawnmower, or a Weedwhacker or a Chainsaw (If not a Heligoflopter Main Gearbox's Drive-Clutch...?), so therefore the Authors Assumed that not much Explainification would be neccessary ? Just(ifiably ?) a thought. Keep on keepin' on. Stay safe. :-p Ciao !
Helicopters use a sprag clutch, which is similar but not the same. Either would work, but a sprag might be smoother and less wearing. Also, there is no need for the centrifugal disengagement in a helicopter. But a ratchet could be used for choppers.
The explanation for the starter mechanism in the Jeppesen manual continues on the next page (10-4). The "ratchet gear" is the engine drive gear and not driven by the starter motor. The pawls are only affected by the springs, the inertia of the overrunning clutch housing, and the force on them once engaged with the engine ratchet drive gear. Centrifical forces are irrelevant.
As I have explained before, there are many ways to get it done. The book version confused me, because it did not match the parts I have, which are for a different system. Centrifugal forces cause the pawls to retract after a certain rpm is reached, at which time they no longer contact the ratchet housing. I do my best here. you need to realize that each engine has it's own way. This is one way. The book describes another.
A pull starter for a Briggs and Stratton, just supersized and beefy. Easy stuff. Would be curious as to the HP rating of the starter motor itself. Toyota Tacomas came with 2 different starter options for the 4 cyl and the V6. One was a mild climate starter(less hp) and one was the cold climate stater(more hp). My Tacoma 4cyl came with the cold climate starter and I think it was 4hp?, but don't quote. Thanks Jay.
I don't know the rating of the starter on this old Avon, but the air turbine starters we have tested for similar sized engines are rated at 650 ft-lbs of torque. Others are rated at 90 Hp.
@AgentJayZ Neat!. Thank you. Most Ingersoll Rand commercial truck wheel guns are 650 foot pounds on +/-150psi. 1" thick splined shaft, for splined sockets. Now, you can get 750 foot pounds in a 20v hand held impact gun. IR also made commercial truck onboard air starters, with about the same foot lbs, give or take, depending on the app. Starters live a hard life, taken for granted in some aspects.
Great episode thanks 🙂 A question...at the start (kind of a pun 🙂) to your left is what looks like a front bearing support. Why are the "arms" from the outer ring to the centre "angled " when they meet the centre? Why don't they just meet at 90deg? Thanks
RR did that with the Avon and some models of the Spey. I think it was an attempt to reduce noise created by the first stage blades as they passed the struts.
@@AgentJayZ The Olympus 593 engines in Concorde also had a similar feature in their 'five strut' (or 'spoke') intakes. They were known as semi-tangential struts and the intention was not primarily to reduce noise (though it might have had some slight effect), but to give the first-stage blades an easier 'ride' through the aerodynamic wake produced by the struts. Instead of the blade experiencing the wake as a single pulse along the full length of the blade, it would have a more gradual effect, thus reducing the level of excitation to which the blades was being subjected. The direction of inclination of the struts was such that the blade root experienced the wake first, which then moved up the length of the blade.
Have you done any videos on the mass flow type fuel flow meter? I'm trying to wrap my head around how this works. Couldn't find anything on your channel.
What would be really super cool, added to this already cool video, would be a video of a starter turning an engine (like maybe a J52, if we’re lucky, or anything) up to maybe 5-10% or so and then stop the starter so we can hear the ratcheting sound as the engine coasts to a stop. 🙂. Does anything else in the engine make clanky sounds as it gets near a stop? Do any of the compressor blades clank, or are they not loose? I’ve gotten the impression they were loose by feeling them in a cutaway engine (I think it was a J47) in a museum (SAC Museum in Nebraska, I think). But a cutaway engine is obviously not an operational one, so maybe I got the wrong impression.
Compressor blades do move, but it's quite a different sound. In a few of my videos of engine tests, I'm right in the inlet, and the starter ratchet is a very clear sound as everything winds down.
@ So, the total sound might be a combination of the ratchet sound and compressor blade sounds? …depending on the model of engine. By this video and your comment, I’m guessing the ratchet is the loudest, from whatever point the pawls are no longer held in until it stops turning. I’m guessing the compressor blades are a more quiet, chattering sound, due to many small blades moving just a little bit and probably only the last 200 rpm or so? I think I now remember one of those cutaway museum engines had an electric motor that turned the engine. It was a long time ago. A quarter of the casing and stator blades were cut away showing the rotating compressor blades. You pushed a button and the motor rotated the engine at probably 30 rpm or so. I think it was covered in clear acrylic so no one could get fingers in there, of course. I seem to recall it made a lot of chattering noise. I don’t recall if it had the ratchet sound. Maybe not, if the pawls were engaged for the “demo” motor to turn the engine. I may have heard the ratchet sound “kick in” on a video of a MiG-17 at Ellington Field in Houston, by RUclipsr, Diesel Thunder. As the VK-1F engine was spooling down, still making some whining sounds, I think I could hear a sort of buzz sound start. Maybe that’s where the springs overcame the centrifugal force and pushed the pawls out. The video cut a few seconds later and I didn’t get to hear it spin down. BTW, they’re looking for a flight worthy J33 engine (I think) for their T-33 down there. Do you think they’ll find one?
Here's a vid of a LM 1500 test where you can hear turbine tip seals slightly rubbing, the very disti9nctive starter ratchet, and a little bit of turbine blade clatter when the engine is rolling down: ruclips.net/video/aJDnWcLuoNg/видео.html starting around 7:45 on.
@ From about 8:19 to 8:33, I can hear what kind of sounds like a card in the spokes of a bicycle wheel. Is that the ratchet sound? Seems similar to what I thought I heard from that VK-1F…centrifugal compressor, which has a solid, 2-sided impeller…so no lose compressor blades like on an axial flow, I assume. Or, I could have been hearing something else, I suppose. Difficult to be sure from a YT video.
Hello Agent Jay Z! I'm into turbojet engines and enjoy watching your videos. But there is another trouble. You don't have subtitles, and unfortunately I don't know English. Therefore, please enable subtitles on your channel. And I'm from Ukraine. And that's how I understood that you are from Canada. And the most important thing. You have two crossed flags on your baseball cap. The flag of Canada and Ukraine! Therefore, thank you very much for supporting Ukraine on your channel. Canada and Canadians have always been among the first to support Ukraine. Especially in this very difficult time for our country. Ukraine is also far from behind in the field of turbojet engines. Our compatriot Arkhip Lyulka is the creator of the world's first two-circuit turbojet engine. And he was born in the Kyiv region - the very heart of Ukraine.
Stay strong, the (sane) USA citizens are with you! If you can do some extra steps, a search for "RUclips audio translation utility" may get you started in ways to take untranslated audio and turn it into Ukrainian. I can't guarantee it works, but it's worth a try.
Hi agent Jay z, I wanted to know how much heat(joules) is actually added and used in combustion chamber of a jet engine. If possible can you explain how tempreture and actual heat(joules) work or effect in jet engines. Thank you
That all depends on so many things. I explain heat rate by how much fuel is burned. Past that, it's not something a tech ever needs to know. It's not listed in the overhaul manual. Many books on combustor engineering are out there. In particular Mattingly's Elements of Gas Turbine Propulsion. Loads and loads of large equations. I handle the parts that are already designed. Designing engines is way above my level of activity.
If the manufacturer quotes a thermal efficiency at the rated power of, say, a gas turbine genset, then you can work it out. If a 20MW set has a thermal efficiency of, say, 25 percent, then the machine is converting only 25 percent of the energy available in the fuel into electrical energy. So, it would need 80MW heat release in the combustion system to 20MW of useful power. Can you convert MW to KJ/sec for yourself?
It's a ratchet clutch. Similar. A sprag clutch uses smooth, oval elements arranged almost like a bearing, slanted in a carrier, and working against a smooth rotating element. A sprag allows movement only in one direction, and has no clicking like a ratchet, because it isn't one. If you've ever seen a silent "ratchet" wrench, those use a sprag. A true ratchet wrench uses a ratchet.
This makes me wonder: couldn't you reduce the wear and tear on those ratchets if you would let the starter motor closely match the speed of the slowing down engine? I mean there would still be clicks but ... not as many.
Ok.... Just watched this. Good video and explanation but .... What about starter/generator type systems? I believe the Saber used this system with the J-47, not sure with the Orendia
Check out my video called Many ways to start a turbine engine. there are many ways to do it. The Orenda starter is direct drive, and becomes a generator spinning at 7800 rpm, so it's designed to handle that.
@@AgentJayZ I'd watched that video back when it came out originally. I just thought the direct drive system might deserve a mention. I believe it was the way the J-34 worked as well, but's it's been a lot of years since I touched one.
You said the aviation Rolls Royce Avon that the outer gear that surrounded the sun gear and planetary gears came out, was out of a 50s airliner. I’m gonna guess you were talking about the de-Haviland Comet?
As AgentJayZ has already told us, there are many ways of starting a jet engine. Electric motors are common, and so are air turbine starters, with the air supplied by a start cart with its own little gas turbine. The Pegasus engine in the Harrier 'jump jet' had its own gas turbine starter. However, most needed to be disconnected from the engine, otherwise they would be driven to overspeed and burst if they were taken up to full engine speed. Having said this, a starter motor can 'double' as an electrical generator, and will not need a disconnect mechanism. The Armstrong Siddeley Viper engine, with which I was familiar, had a starter-generator arrangement, and the engines in the B.787 Dreamliner, with its 'more electric' features, have large generators that 'double' as starter motors.
I am a diesel engine mechanic by trade and vintage Canadian aircraft buff, with specific interest in the CF-100. .I love your non technical way of explaining how things work so that anyone can understand . You have certainly helped me understand the workings of a gas turbine engine better then any text book could. I'm so happy to have found your channel. Please keep up the great work!
The Orenda 14, which I have a few vids on, and is used in the Canadair Sabre 6, is internally identical to the 11, which was used in the CF-100.
@@AgentJayZ I think there is a Mark5 sitting in the Heritage Museum in Hamilton Ontario that could use a pair if 11's should they every choose to take it to flight status. It really is a shame that there is not at least one of these beautiful birds preserved in flying condition.
We've got a few 11s in good restorable condition, but museums don't have any money. We can not afford to donate the work needed to get them running.
@@AgentJayZ Yes Sir! I totally get it. This would not be a cheap project, and only a select few with any interest in it.
"36.000 rpm ... yeah ... the starter motor is not gonna like that" XD had me rolling.
Thanks for showing us the real parts moving. Diagrams are nice but seeing it "in action" is so much more explanatory.
"Debris rapidly exiting the scene . . ." hahahhahahhahhahahha
Agent Jay Z, I spent 12 years as a mill/turn machinist at an aerospace MRO facility, and the “ratchet wheels”, and the pawl carrier housings were a common job that I routinely ran. Thanks for the assembly breakdown… nice to see how these components are actually assembled and function!
Were you repairing them? What were some of the most common problems you saw?
@ No sir. These were OEM spec parts that we manufactured, via licensing agreement. All parts we made in house, except for the actual pawls, which were procured from a forging plant, then final machined to meet the requirements for application.
Thank you so much for taking the time to explain these components down to the level of non-specialists. 🙂
"We're gonna see debris rapidly exiting the scene..."
That's a beautiful description LOL 🤣🤣🤣
Excellent explanation on this connector!!
I do love it when true mechanics go in-depth on seemingly (to a layman) incomprehensible machinery...
My dad was a lifelong mechanic, or an 'oily rag', since he was 17 until he passed away at 61 in 1999, and he so would've loved these videos... His passion for engines sort of affected me obviously 😎👍
Thanks for posting! very interesting.
Fun fact: in smaller helicopter turboshaft engines like the Safran Arriel or PWC PW207 the starter is also the electrical generator and it is permanently coupled to the gas generator main shaft (through a gear reduction).
That is what I assumed of to be the case in most engines - that you would use the starter motor as a generator. But then I saw some APU diagrams where starter and generator were to seperate units with very different configurations.
Thanks for the deep-dive on a turbine starter clutch, it's nice to get the bits and bobs explained.
When I was a crew chief on B-52s and ran engines for ground tests, were taught to keep our finger on the starter switch (8 starter switches on a B-52) for the engine we were starting so we would not forget to turn the switch off at 40% to avoid ovetspeeding the starter.
The machining in these engines is just crazy good
Great question, and the answer explains many things. Genius design, fantastic explanation.
Thanks for enlightening us on this! Interesting design, centrifugal force released one way clutch.😊
my favorite part about gt mechanics is that we all understand the engine from a perspective that doesn't require complex nomenclature. we KNOW it, we just don't need it to explain how this works. "gear type thing" is perfectly sufficient
I love it.
I thought the clacking on spin-down was due to the lose blades shifting when there wasn't any centripetal force holding them in fixed locations at their roots.
Thanks.
There are several noises all happening. Blades make a clicking sound, not as loud as the starter ratchet.
This is Ahmed Elrawy from Egypt
Thanks a lot for these beautiful details hope you are good
Thanks Jay. golden video material right here
The starter ratchet reminds me of a recoil type rope starter on a lawn mower engine. How it engages and disengages are similar. Only it’s the inverse. The recoil starter engages the teeth in the gear attached to the engine crank shaft. And it releases when the rope is pulled no longer being pulled.
I'm not a jet guy & i enjoyed it .
Fascinating part of the engine
Auto rotation requires these bits of magic
Collective down
Good video
Great explanation. The piece parts make it clear.
That's a big one! If you get to pull the starter on your start cart someday, you'll see the baby version in there.
I enjoyed this chaotic explanation very much. This was my Jay z agent!
Nice demonstration 👍👍🇩🇰🇩🇰🇩🇰
In the automotive transmission world, we call them Sprag clutches Look up the one for a chevy turbo 400 reverse sprag. Granted, the planetary is not integral to the unit but the sprag is a pretty cool little one way clutch.
I see so the Sprag engages with RPM the opposite of the one shown here.
Thanks for the nice explanation!
Oh wow, the bots are miserable again today. The clutch looked interesting from the thumbnail, but as it's 1 am I'll check it out tomorrow Jay. 😊
I am ready these days. Every new upload there are usually a half dozen bikini bots to first comment. They are escorted out.
Thank you! It's eloquent!! It still seems overly complicated but beautiful!!
I 'd like to share with you a bit of jet engine history.
I've just been watching a TV documentary about the winter of 1947 in the UK, when we had snow on the ground for over seven weeks, which I think I can just remember. So what has this got to do with jet engine history, you may ask?
Well, there was a brief clip of two Whittle-style jet engines with reverse-flow combustion chambers (they were probably R-R Wellands) mounted on a railway truck, being used as snow blowers to clear the track.
Thanks for sharing amazing mechanism
Thanks, always wondered about that, so simple. Some lawn mowers had the same principle.
"...You spin me round round baby right round, like a ratchet clutch right round round round..."
G'day Jay,
Every Heligoflopter has a similar setup, between Powerplant and Main Reduction Gearbox, so that if the Fire blows out - then the Main Rotor, by Autorotating..., is able to drive the Tail-Rotor's Driveshaft via the Main Re-Drive Gearox.
Also, pretty much every Small Engine featuring a
"Spring Recoil" Starter Pulley, has a simplificated low-budget Plasticised version of what is
"Officially" termed a,
"Spring-assisted Centrifugal-Sprag type Clutch", otherwise colliquially termed a
"Borg-Warner Clutch"...; presumably named after the Inventor, or they who first took it to market...(?).
Maybe the Writers of the Jet Engine Textbooks assumed that anybody aspiring to tweak Spanners on a Turbine Engine..., would have, previously at some point, pulled apart
A Pullstart
From a Lawnmower, or a Weedwhacker or a Chainsaw
(If not a Heligoflopter Main Gearbox's Drive-Clutch...?), so therefore the Authors
Assumed that not much
Explainification would be neccessary ?
Just(ifiably ?) a thought.
Keep on keepin' on.
Stay safe.
:-p
Ciao !
Helicopters use a sprag clutch, which is similar but not the same. Either would work, but a sprag might be smoother and less wearing. Also, there is no need for the centrifugal disengagement in a helicopter.
But a ratchet could be used for choppers.
The explanation for the starter mechanism in the Jeppesen manual continues on the next page (10-4). The "ratchet gear" is the engine drive gear and not driven by the starter motor. The pawls are only affected by the springs, the inertia of the overrunning clutch housing, and the force on them once engaged with the engine ratchet drive gear. Centrifical forces are irrelevant.
As I have explained before, there are many ways to get it done. The book version confused me, because it did not match the parts I have, which are for a different system. Centrifugal forces cause the pawls to retract after a certain rpm is reached, at which time they no longer contact the ratchet housing.
I do my best here. you need to realize that each engine has it's own way. This is one way. The book describes another.
@@AgentJayZ I'm not criticizing anything. I just wanted to clear up the confusion. I thought it was a good thing.
Holy shit this is so cool
A pull starter for a Briggs and Stratton, just supersized and beefy. Easy stuff.
Would be curious as to the HP rating of the starter motor itself.
Toyota Tacomas came with 2 different starter options for the 4 cyl and the V6. One was a mild climate starter(less hp) and one was the cold climate stater(more hp). My Tacoma 4cyl came with the cold climate starter and I think it was 4hp?, but don't quote.
Thanks Jay.
I don't know the rating of the starter on this old Avon, but the air turbine starters we have tested for similar sized engines are rated at 650 ft-lbs of torque. Others are rated at 90 Hp.
@AgentJayZ Neat!. Thank you. Most Ingersoll Rand commercial truck wheel guns are 650 foot pounds on +/-150psi. 1" thick splined shaft, for splined sockets.
Now, you can get 750 foot pounds in a 20v hand held impact gun.
IR also made commercial truck onboard air starters, with about the same foot lbs, give or take, depending on the app.
Starters live a hard life, taken for granted in some aspects.
Ahh, giant freehub. Wish my bike would spin up and hold back the pawls at speed like these starters.
Yes. My X-drive hub has failed twice. Broken pawls.
Thanks.
Great video, as usual. Is this type if starter universal?
Nothing is really universal. Have a look at my recent video: Many ways to start a turbine engine.
Great episode thanks 🙂 A question...at the start (kind of a pun 🙂) to your left is what looks like a front bearing support. Why are the "arms" from the outer ring to the centre "angled " when they meet the centre? Why don't they just meet at 90deg? Thanks
RR did that with the Avon and some models of the Spey. I think it was an attempt to reduce noise created by the first stage blades as they passed the struts.
@@AgentJayZ The Olympus 593 engines in Concorde also had a similar feature in their 'five strut' (or 'spoke') intakes.
They were known as semi-tangential struts and the intention was not primarily to reduce noise (though it might have had some slight effect), but to give the first-stage blades an easier 'ride' through the aerodynamic wake produced by the struts.
Instead of the blade experiencing the wake as a single pulse along the full length of the blade, it would have a more gradual effect, thus reducing the level of excitation to which the blades was being subjected.
The direction of inclination of the struts was such that the blade root experienced the wake first, which then moved up the length of the blade.
That was great!
Have you done any videos on the mass flow type fuel flow meter? I'm trying to wrap my head around how this works. Couldn't find anything on your channel.
We don't use them, so I can't help there.
What would be really super cool, added to this already cool video, would be a video of a starter turning an engine (like maybe a J52, if we’re lucky, or anything) up to maybe 5-10% or so and then stop the starter so we can hear the ratcheting sound as the engine coasts to a stop. 🙂. Does anything else in the engine make clanky sounds as it gets near a stop? Do any of the compressor blades clank, or are they not loose? I’ve gotten the impression they were loose by feeling them in a cutaway engine (I think it was a J47) in a museum (SAC Museum in Nebraska, I think). But a cutaway engine is obviously not an operational one, so maybe I got the wrong impression.
Compressor blades do move, but it's quite a different sound. In a few of my videos of engine tests, I'm right in the inlet, and the starter ratchet is a very clear sound as everything winds down.
@ So, the total sound might be a combination of the ratchet sound and compressor blade sounds? …depending on the model of engine. By this video and your comment, I’m guessing the ratchet is the loudest, from whatever point the pawls are no longer held in until it stops turning. I’m guessing the compressor blades are a more quiet, chattering sound, due to many small blades moving just a little bit and probably only the last 200 rpm or so?
I think I now remember one of those cutaway museum engines had an electric motor that turned the engine. It was a long time ago. A quarter of the casing and stator blades were cut away showing the rotating compressor blades. You pushed a button and the motor rotated the engine at probably 30 rpm or so. I think it was covered in clear acrylic so no one could get fingers in there, of course. I seem to recall it made a lot of chattering noise. I don’t recall if it had the ratchet sound. Maybe not, if the pawls were engaged for the “demo” motor to turn the engine.
I may have heard the ratchet sound “kick in” on a video of a MiG-17 at Ellington Field in Houston, by RUclipsr, Diesel Thunder. As the VK-1F engine was spooling down, still making some whining sounds, I think I could hear a sort of buzz sound start. Maybe that’s where the springs overcame the centrifugal force and pushed the pawls out. The video cut a few seconds later and I didn’t get to hear it spin down.
BTW, they’re looking for a flight worthy J33 engine (I think) for their T-33 down there. Do you think they’ll find one?
Here's a vid of a LM 1500 test where you can hear turbine tip seals slightly rubbing, the very disti9nctive starter ratchet, and a little bit of turbine blade clatter when the engine is rolling down:
ruclips.net/video/aJDnWcLuoNg/видео.html
starting around 7:45 on.
@ From about 8:19 to 8:33, I can hear what kind of sounds like a card in the spokes of a bicycle wheel. Is that the ratchet sound? Seems similar to what I thought I heard from that VK-1F…centrifugal compressor, which has a solid, 2-sided impeller…so no lose compressor blades like on an axial flow, I assume. Or, I could have been hearing something else, I suppose. Difficult to be sure from a YT video.
That is the starter ratchet. I don't know, bud... it just could not be more obvious. Especially when I explained to you exactly what you are hearing.
Hello Agent Jay Z! I'm into turbojet engines and enjoy watching your videos. But there is another trouble. You don't have subtitles, and unfortunately I don't know English. Therefore, please enable subtitles on your channel. And I'm from Ukraine. And that's how I understood that you are from Canada. And the most important thing. You have two crossed flags on your baseball cap. The flag of Canada and Ukraine! Therefore, thank you very much for supporting Ukraine on your channel. Canada and Canadians have always been among the first to support Ukraine. Especially in this very difficult time for our country. Ukraine is also far from behind in the field of turbojet engines. Our compatriot Arkhip Lyulka is the creator of the world's first two-circuit turbojet engine. And he was born in the Kyiv region - the very heart of Ukraine.
Stay strong, the (sane) USA citizens are with you! If you can do some extra steps, a search for "RUclips audio translation utility" may get you started in ways to take untranslated audio and turn it into Ukrainian. I can't guarantee it works, but it's worth a try.
Hi agent Jay z, I wanted to know how much heat(joules) is actually added and used in combustion chamber of a jet engine.
If possible can you explain how tempreture and actual heat(joules) work or effect in jet engines.
Thank you
That all depends on so many things. I explain heat rate by how much fuel is burned. Past that, it's not something a tech ever needs to know. It's not listed in the overhaul manual.
Many books on combustor engineering are out there. In particular Mattingly's Elements of Gas Turbine Propulsion.
Loads and loads of large equations.
I handle the parts that are already designed. Designing engines is way above my level of activity.
If the manufacturer quotes a thermal efficiency at the rated power of, say, a gas turbine genset, then you can work it out.
If a 20MW set has a thermal efficiency of, say, 25 percent, then the machine is converting only 25 percent of the energy available in the fuel into electrical energy. So, it would need 80MW heat release in the combustion system to 20MW of useful power. Can you convert MW to KJ/sec for yourself?
Ahhh, its just like a planetary gear set with a sprag clutch in an automatic trans but with big teefs
Simple, but effective
if i said that to anyone they would think im crazy
A1 content. Thank you.
Would the starter ratchet classify as a sprag clutch? A really, really overbuilt sprag clutch?
It's a ratchet clutch. Similar. A sprag clutch uses smooth, oval elements arranged almost like a bearing, slanted in a carrier, and working against a smooth rotating element. A sprag allows movement only in one direction, and has no clicking like a ratchet, because it isn't one.
If you've ever seen a silent "ratchet" wrench, those use a sprag. A true ratchet wrench uses a ratchet.
This makes me wonder: couldn't you reduce the wear and tear on those ratchets if you would let the starter motor closely match the speed of the slowing down engine? I mean there would still be clicks but ... not as many.
The ratchet is there to do what it does. The wear is minimal, and everything is restored to serviceable at overhaul. It's a system that works.
Interesting
Starter ratchet that if I am not mistaken is sprag clutch ? Yes ?
no
Ok.... Just watched this. Good video and explanation but .... What about starter/generator type systems? I believe the Saber used this system with the J-47, not sure with the Orendia
Check out my video called Many ways to start a turbine engine. there are many ways to do it.
The Orenda starter is direct drive, and becomes a generator spinning at 7800 rpm, so it's designed to handle that.
@@AgentJayZ I'd watched that video back when it came out originally. I just thought the direct drive system might deserve a mention. I believe it was the way the J-34 worked as well, but's it's been a lot of years since I touched one.
You said the aviation Rolls Royce Avon that the outer gear that surrounded the sun gear and planetary gears came out, was out of a 50s airliner. I’m gonna guess you were talking about the de-Haviland Comet?
Maybe that or a Caravelle.
@ had to look up what a Caravelle was. Fascinating jets
That's an overly complicated way to do it. All you need is someone to shout "Contact" to the pilot. Then they spin the propellor by hand
16:12 OMG!!!
So confused, and that’s an easy thing to do. I thought pneumatics/air was used to get the engine up to speed before introducing the fuel?
Very rarely. That's known as air impingement starting. Check out my video called "Many ways to start a turbine engine"
As AgentJayZ has already told us, there are many ways of starting a jet engine. Electric motors are common, and so are air turbine starters, with the air supplied by a start cart with its own little gas turbine. The Pegasus engine in the Harrier 'jump jet' had its own gas turbine starter.
However, most needed to be disconnected from the engine, otherwise they would be driven to overspeed and burst if they were taken up to full engine speed. Having said this, a starter motor can 'double' as an electrical generator, and will not need a disconnect mechanism.
The Armstrong Siddeley Viper engine, with which I was familiar, had a starter-generator arrangement, and the engines in the B.787 Dreamliner, with its 'more electric' features, have large generators that 'double' as starter motors.
IIRC, the speed ratio between the planet carrier and the sun gear is ((the number of teeth on the crown/the number on the sun) +1) :1.
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