The fuel/oil heat exchanger is such a genius device. Warms fuel that would otherwise be too cold coming from the wings, and cools the oil that would be too hot without it. There’s literally zero downside, and that’s my favourite thing about engineering.
AgentJayZ - i cant put in words how im soaking up your videos. I work in IT and nothing could be more far off than jet engines for me - but i cant get enough! i am grateful for every minute you put in these videos. thank you.
NOW DAYS... IT is a whole lot closer to aeronautics than ever! Not only do computers operate the engines and pretty much every other operation of the craft, they also communicate with tens, hundreds or thousands of other computers in a massive intelligence network. Battlefield intelligence is growing ever more complex, multi-layered and eyes-on dependent. This means that IT is not just web browsers and bank notes, its also flight and battle data.
Thanks for rekindling some old memories from the 50's for me. I had almost forgotten about the terms lean die out, and rich blowout, which occurred with the older engines due to rapid throttle movement. It's easy to overlook how many advances in Engine tech took place over a span of half a century. I'm nearing the end of my life and looking back at the many improvements in human comfort, and convenience due to technical improvement I can only say WOW! That was cool.
It's hard to imagine how those guys figured all this stuff out with pencil, paper, and slide rule. That engine is as old as I am. Utmost respect to those jet geeks!
Thanks for another video, sir. Old technology from the late 1950s, early 1960s is cool, man. I happen to like hifi audio equipment from that era with vacuum tubes and point to point wiring rather than printed circuit boards. Infinitely repairable instead of throw-away, and often fun to work on.
Back in the Late 67-68 I was on a combined systems (Check Out) crew for the AGM-28B Hound Dog MSL. it had a J52-P3 Turbo-Jet engine. On Engine shut down I had to be sure to place a bucket under the FUEL Control or I would have to wipe-up the floor of about a pint of JP4.
I believe you have answered a long time question of mine that with electronic fuel delivery could be by-passed as the jet could suck fuel themselves from the tanks will need to watch this turbojet fuel system video again tomorrow when not so tiered, thanks as always MIC
A massive thank You for still uploading those videos! Your channel is by far the best source of professional information on the entire platform i know about.
“Hope that aids in your understanding” Jus thought you’d appreciate that bit of friendly assistance on that last line you were having a fair bit of trouble spittin’ out....no problem, anytime, anytime! Lol
The reason the military uses apparently backwards nomenclature descriptors is because of inventory hierarchical classification. For example the fact that a cooler goes on an aircraft is less important that it be classified as a "cooler" first and its much less important that it goes on an "aircraft". It could go on a boat engine. But it's a "cooler" first as a nomenclature descriptor. Basically, the nomenclature arrangement is for the supply person who pulls the part off the shelf, not the pilot or the mechanic.
It's not just the military that uses this form of nomenclature. In my experience, it's been standard practice throughout the industry on both military and civil jet engines for decades.
I like the smiley! I wish I could go back in time by only 20 minutes, when I decided not to bother responding to hi you's comment. I was gonna say: "Some people have called it a fuel heater, but they are uninformed." Now I realize I shoulda!
It's surely 5-10 times smaller than an air cooled exchanger would have to be, and creates no air flow problems. Cooling requirements are probably closely matched to fuel consumption too.
@@fascistpedant758 Some engines do have ACOCs, in addition to FCOCs. Turboprops almost invariably have them, because of the need to deal with the heat rejection from the gearbox.
Years ago we had an RB211-22b on an L1011 that was drinking oil. It caused an air turnback on a ferry flight. it was on the ground for three days while we tried to figure out the problem. An engineer from Rolls Royce was sent to help us. I was talking with him and he was telling me how the FCOC was regulated by wax which would expand and contract to open and close the valve to the FCOC based on oil temp. I thought it was rather genius using wax. The problem ended up being a bolt that was somehow left in a scavenge line during overhaul.
these hydraulic/mechanical fuel controllers are really cool. If you have a schematic of the internals of the fuel control you should make a video about that so that people can appreciate how complex it is even though it was made in 1955.
In early 1963, on my first placement as an apprentice, straight out of the training school, I was put into the Viper and Double Mamba build shop. After an introductory spell on the strip section, I was let loose on Double Mamba build. I got a large union nut cross-threaded, realised what I'd done, and was in the process of correcting it, when I was spotted. I was ticked off, but given credit for doing so.
Great video, I’m supposed to start school to become an A&P in May and I’m very excited. It might be pushed back though because of all the uncertainty around coronavirus☹️
Interesting that inlet and high pressure section doesn't handle altitude compensation since inlet pressure tells you the effective altitude (air density).
Among the many other things I take away from your videos... I'm definitely more appreciative of some of the more "maintenance friendly" engine designs of the past 20 years.
Jay, I love, and hate this old technology. All of the plumbing has been replaced by wiring. Makes me wonder what is going to be the next big step to improve control of the power output. I work on cars at a dealership for a living, but I have always been interested in aviation. I don’t know if your job pays well, but it revolves around the highest tech of the time and that is almost like being there when they were built!
I've talked to a few retired military pilots, and they all have the same list of favorite planes to fly based on fun, feel, and thrills. In no particular order: Supermarine Spitfire North American Aviation P-51 Mustang North American Aviation F-86 Sabre (actually, they prefer the Canadair Sabre 6) McDonnell Douglas F-4 Phantom 2 All old, and all with analog engine controls. I think I would prefer an all manual carbureted v-12 rear wheel drive roadster to a drive by wire digital fuel injected KERS hybrid with launch control and gps integrated ABS with paddle shifters. Just me...
AgentJayZ those aircraft are some of my favorite, although I never got the chance to fly them personally. But I did get my private license. If you ever get a chance, go out to the Reno air races, they have a good mix of warbirds, Jets, and new light aircraft racing around pylons in the desert. Great sights and sounds. On a side note, is the Sabre 6 a higher powered version of the f-86?
I was at the Gold Cup in 2014, and had a pit pass. Amazing experience. The Sabre 6 was a Canadian license built version of the F-86F, and it used a Canadian designed and built engine, that produced 7200 lbs of thrust. (Last month, one that I built made 7700) In the F86-F, the GE J47 produced 5500 lbs of thrust. The J47 is a great engine, with more combat hours than any other jet engine ever. The two engines are different, and you can't say that one is a higher powered version of the other. The Sabre dominated the sky in its day with either engine. Check out my vids of J47 tests.
"Cooler, Oil, Tubular, Aircraft ... I don't know why we say it backwards." Military method of classifying things, go from the least specific to the most specific identifying parameter.
No. EPR is a pilot, feel good thing. It's meaningless, except to give a general indication of engine operation. I made a video called Jet Engine Thrust a few years ago. It's a bit of a rant, but it's about the fact that jet engines are not pressure devices, but acceleration devices. I still chuckle at the question I asked back then: how fast does a hydraulic jack fly? Here it is... it's OK if you don't like it. th-cam.com/video/BeuP2BAky74/w-d-xo.html
Thank you, I watched your link. You seemed a little pissed off. Can't say I blame you. I did say "if that applies" because I did not know. I was thinking that about approximately 3:55 when you were talking about the difference in pressure between the two lines and I thought it may be similar. I believe pilots set power based on the EPR. I remember their was a crash in 82 of a Air Florida Flight 90. I believe part of the problem was the EPR sensors were iced up and gave incorrect power settings.
From a previous comment: 100% is the nominal max recommended power, beyond which component life is shortened due to thermal stress. Takeoff power is 102% of that value, and is limited to 5 minutes duration. These are old military turbojets. I can't say if modern airliner engines follow the same rules. blancolirio might know. He flies the 777. Check out his channel.
@WanJae42 No, they stuck with it to not confuse numbers from earlier testing. Emergency power was 109% and they had been tested to 111%. Now with development of SLS they have tested to 113%.
Good evening sir, I believe anything from your, very respectful video and very smart theory. I always watching and share to son, God bless you sir, hoping God always given a good health. my family loves you.
Amazing video. One quick question, I heard somewhere that the fuel:air mixture of a jet engine is far more lean that pistons, but I have a hard time wrapping my head around it. So, what is the fuel:air mixture of a jet engine and why is it different to a piston engine? Thanks a lot, your videos are very helpful
@@AgentJayZThanks for the video, just watched it. You just made my day. Did not expect you to respond to my comment let alone make a video. Very insightful video, answered a long time question of mine. Now you got me interested in turbine blade materials and their limiting factors lol.
Agent Z...the naming convention of bendix was created for quick visual identification, stocking, ordering, ie. Your last shot of oil cooler: “Cooler, Oil, Tubular, Aircraft” correlates: “Function, System, Construction Type, Vehicle (or Final Assembly Unit)... I worked in automotive aftermarket parts in my teenage days, and believe it or not I ask that very question to a sales rep once...go figur
Awesome. Thanks. I still think the same amount of information is contained in the phrase a human being would use: vehicle, construction type, system, function... aircraft tubular oil cooler. Saves all those commas, too!
100% is the nominal max recommended power, beyond which component life is shortened due to thermal stress. Takeoff power is 102% of that value, and is limited to 5 minutes duration. These are old military turbojets. I can't say if modern airliner engines follow the same rules. blancolirio might know. He flies the 777. Check out his channel.
Is there an oil fill / air vent procedure for the fuel system? (Like on Diesel piston engines.) I.e. if the fuel system was completely apart for servicing, is there a special procedure to get fuel back into every part of the fuel system and any air out? Preventing any air pockets? Or is the fuel feed pressure from the boost pump in the tanks enough to get the fuel system started. I.e. Boost pump delivers fuel up to the main fuel pumps, they deliver fuel to the rest of the system and any residual air is simply (?) blown out of the fuel nozzles. p.s. Many thanks for these in depth explanations.
Yeah, there are bleed ports on the fuel pumps, because they are the highest point in the fuel system. I may make that part of an upcoming vid. You could just spin the engine up on the starter, and pump about a gallon of air through it until the fuel gets there, or use the fuel bleed ports. Engineers are pretty dang smart, I tell ya!
4:30 It's smoke limitation just like on a diesel engine. Fuel quantity is limited to certain amount according to either boost pressure or air mass flow or lambda measured in the exhaust. Adjusting the limitation maps closer to actual smoke limit you will get better response of the engine.
Not a piston engine, no lambda sensor, smoke's got nothing to do with it. The compensation is to ensure thrust stays consistent as the plane gains or loses altitude, so the pilot does not have to constantly adjust the throttle during combat.
Thank you for the videos ! btw... I do not understand how bypass air is different from a propeller? If most of the thrust in a jet engine comes from by pass why not just have a prop plane not a jet?
A turbofan puts a greater acceleration into the air than a prop does. A 3,000 Hp piston engine once swung a 13 foot prop. An 80 thousand Hp turbofan spins a 9.5 foot fan. Maybe it's the ducting, but also the difference in blade number. The discharge of the fan is moving much faster than the prop wash.
AgentJayZ Hey mate, just out of curiosity - do you get many turbofans in the shop (either low or high bypass), or is it mainly the old but gold engines? Also, please forgive a very stupid question, but do you see turbofans on ground/turboshaft installations? Or is it completely pointless and I’m not understanding right? Fairly sure all of the second question is part of the answer. Thanks in advance, and cheers from Australia. P.S. I *really* need to send you a bigger flag one day. You know, to... compensate for things.
In high bypass turbofans, most of the engine power is harvested by the LP turbine to drive the fan. It's a fairly simple modification of the design to increase the amount of energy harvested by the LPT, and the delete the fan itself, so the LPT drives the output shaft with almost all the power created by the burning fuel. That is exactly what GE did with the CF6 series of engines to create the LM 2500. It started out as a 25 thousand Hp engine, and has grown to almost twice that. Check out my LM 2500 videos!
Hey, I have just subscribed! I love your videos! Now I have a question that will sound very insane ! All issues aside, which I know I will encounter many! Do you think a very skilled person can build a 500Kg thrust low bypass jet engine!! I have no problem getting the fuel, I can do casting, CNC machining, computerised MIG welding etc... I want to make a dream come true.
Building a turbofan engine of your own design? Whoa, that is the project of all projects. A million times easier, but still requiring great skill and determination, would be to restore a small turbojet or helicopter turboshaft. I have several videos about designing and building your own engine. Search box on channel page.
@@AgentJayZ Thanks for coming back to me. Actually my only huge concern would be oil sealing, due to the temperatures involved. I have already gathered some precious information. I was thinking about a fearly simple twins pool turbofan. I already have designed most of the main parts and now learning about powder 3D printing and wax molding... My actual headache is about the injectors design. I think I'm going crazy but in a good way 😂🤣.
Oil cooler, so it's different from FOHE (Fuel Oil Heat Exchanger), that is mentioned to heat cold fuel and melt possible ice crystals. And hot engine oil is used to heat fuel?
Both things happen, because its a heat exchanger. But the manual calls it an oil cooler. If anybody wants to call it french toast, that's fine with me... just not in my shop.
If I am intepreting right the F-86 cutaways available, the manual (as quoted by Jay) calls it the right thing. In this ship the fuel tanks are inside the fuselage and so are not exposed to cold soaking as it happens in airliners fitted with integral fuel tanks built as part of the wings. In the Saber, the only fuel exposed to the external air temp. would be the one inside the drop tanks, but I doubt even this fuel would have the time to get too cold, as the drop tanks will be the first to get depleted. So, IMHO, the main function of the oil cooler is indeed to cool down the oil, the heating up of the fuel being a welcomed by-product, but not as critical as in an airliner. Great video, by the way!!
I don't know why there is such consternation, analysis, and unnecessary debate. Orenda built the engine, and they call it an oil cooler. All comments on the subject are useless, irrelevant, and a complete waste of effort. These are the facts, and the facts don't give a shit what anybody thinks. OK, then?
RB211s used to have FCOCs (fuel cooled oil coolers): it appears that Trents now have FOHEs (fuel/oil heat exchangers). There is essentially no difference: they perform exactly the same function.
Does the 1-to-6 fuel distribution block ensure the same fuel flow to each fuel nozzle or does it modulate the flow to each fuel nozzle based on how rich/lean that particular combustor can is burning?
I believe the fuel distribution blocks function is to flow the same amount of fuel to each nozzle regardless of differences in resistance. My instinct is that their is a fixed displacement mechanism (Probably similar in form to a gear or vain pump) for each burner. These "pumps" would not necessarily be driven mechanically but by the flow of fuel through them. If each fixed displacement device where attached to each other by a shaft, then each output would flow the same amount of fuel regardless of the resistance experienced at each output.
Thanks, i was kind of thinking this is the case.. But wanted to ask if there would have been some differences. Thanks for the great and fun answer AgentJayZ!
That lever, as well as the one on the emergency fuel control, is connected ( by the green rods) to a pivot which is connected to a cable that goes to the throttle handle in the cockpit. You can see the throttle handle in a video I made comparing the start sequence in the jet and in the test cell.
JetA is the design fuel. Kerosene, diesel, are interchangeable with minor adjustments. AvGas or any gasoline is a suitable alternate fuel with minor adjustments and shortened service life for fuel system components. In a pinch, if it burns, it turns.
Each part is made of the most suitable material. Not making a list. You need to be more specific. Also: I put the things together; I don't really need to know what they are made of.
Bonus pints for the correct spelling of phlegm... or is it flegm now? And remember to never dispose of the contents of the dephlegmator in the re-bigulator.
I presume there's an important reason why fuel reaching the dump valve -- and subsequently dumped or captured -- should never be poured back into a fuel tank?
The usual amount dumped out is about 500ml, or a pint. This engine uses between 2 and 20 gallons per minute in operation. Also, the system was designed in the 1950s for a military fighter. The amount wasted is an insignificantly small quantity.
Any removal from active service, for whatever reason, requires complete "reactivation" service of the entire aircraft. All systems checked, fluids topped up and bled.
@@AgentJayZ many thanks, Id be curious to see more details of a reactivation service if its something youre ever able to cover in a video, no worries if not though and thanks for the response
I like models copy's of the real thing like my M67, but like that oil cooler with words all back to front, this thing says grenade, hand, frag, delay, M67
The fuel/oil heat exchanger is such a genius device. Warms fuel that would otherwise be too cold coming from the wings, and cools the oil that would be too hot without it. There’s literally zero downside, and that’s my favourite thing about engineering.
AgentJayZ - i cant put in words how im soaking up your videos. I work in IT and nothing could be more far off than jet engines for me - but i cant get enough! i am grateful for every minute you put in these videos. thank you.
NOW DAYS... IT is a whole lot closer to aeronautics than ever!
Not only do computers operate the engines and pretty much every other operation of the craft, they also communicate with tens, hundreds or thousands of other computers in a massive intelligence network.
Battlefield intelligence is growing ever more complex, multi-layered and eyes-on dependent.
This means that IT is not just web browsers and bank notes, its also flight and battle data.
Thanks for rekindling some old memories from the 50's for me. I had almost forgotten about the terms lean die out, and rich blowout, which occurred with the older engines due to rapid throttle movement. It's easy to overlook how many advances in Engine tech took place over a span of half a century. I'm nearing the end of my life and looking back at the many improvements in human comfort, and convenience due to technical improvement I can only say WOW! That was cool.
Welcome to Jet City , Dave!
It's hard to imagine how those guys figured all this stuff out with pencil, paper, and slide rule. That engine is as old as I am. Utmost respect to those jet geeks!
I wish I had this in this manner when I was in college and university . Never too late to learn things the real way . Thanks again mate
What a great explanation, I'm Brasilian and I'm learning so many things and terms used in aviation by watching your videos, thanks a lot sr.
Thanks for another video, sir. Old technology from the late 1950s, early 1960s is cool, man. I happen to like hifi audio equipment from that era with vacuum tubes and point to point wiring rather than printed circuit boards. Infinitely repairable instead of throw-away, and often fun to work on.
I live near the SAC museum and they have a J79 and I can identify every system on it because of your vids. Keep it up, they are great!
Back in the Late 67-68 I was on a combined systems (Check Out) crew for the AGM-28B Hound Dog MSL. it had a J52-P3 Turbo-Jet engine. On Engine shut down I had to be sure to place a bucket under the FUEL Control or I would have to wipe-up the floor of about a pint of JP4.
I believe you have answered a long time question of mine that with electronic fuel delivery could be by-passed as the jet could suck fuel themselves from the tanks
will need to watch this turbojet fuel system video again tomorrow when not so tiered, thanks as always MIC
A massive thank You for still uploading those videos!
Your channel is by far the best source of professional information on the entire platform i know about.
What better way to start one´s Saturday than with a video from the shop. Wunderbar!
If I was Spock I would raise my eyebrow and say, "Fascinating."
“Hope that aids in your understanding”
Jus thought you’d appreciate that bit of friendly assistance on that last line you were having a fair bit of trouble spittin’ out....no problem, anytime, anytime!
Lol
The reason the military uses apparently backwards nomenclature descriptors is because of inventory hierarchical classification. For example the fact that a cooler goes on an aircraft is less important that it be classified as a "cooler" first and its much less important that it goes on an "aircraft". It could go on a boat engine. But it's a "cooler" first as a nomenclature descriptor. Basically, the nomenclature arrangement is for the supply person who pulls the part off the shelf, not the pilot or the mechanic.
interesting - thanks
It's not just the military that uses this form of nomenclature. In my experience, it's been standard practice throughout the industry on both military and civil jet engines for decades.
@@grahamj9101 You are correct, but I believe it was formulated by the military first as a standard practice.
Beautiful work . lots of thanks....you uploaded this unique information..... THANKS AGAIN
This is stunning for a 1950's design. Many would be happy with this even today.
Nobody I know of has converted their Sabre Jet to use a different, more modern engine.
thanks..for the flashback to 1965 and learning the fuel control for the J52-P3
Thanks Agent, very interesting to see how that was made in the past (it has change à lot since then)!
I love that they used the tubuler aircraft oil cooler using fuel to cool rather then passive air oil cooling.
Very interesting
I like the smiley! I wish I could go back in time by only 20 minutes, when I decided not to bother responding to hi you's comment. I was gonna say: "Some people have called it a fuel heater, but they are uninformed."
Now I realize I shoulda!
It's surely 5-10 times smaller than an air cooled exchanger would have to be, and creates no air flow problems. Cooling requirements are probably closely matched to fuel consumption too.
@@AgentJayZ I'm surprised a man like you can't go at least 20 minutes back in time. What with you jet engines and all.
@@fascistpedant758 Some engines do have ACOCs, in addition to FCOCs. Turboprops almost invariably have them, because of the need to deal with the heat rejection from the gearbox.
Very cool! So amazing!
Thank you from Greece. Amazing video!
Thanks Jay! Very interesting, as always! Be safe up there!! --gary
Years ago we had an RB211-22b on an L1011 that was drinking oil. It caused an air turnback on a ferry flight. it was on the ground for three days while we tried to figure out the problem. An engineer from Rolls Royce was sent to help us. I was talking with him and he was telling me how the FCOC was regulated by wax which would expand and contract to open and close the valve to the FCOC based on oil temp. I thought it was rather genius using wax. The problem ended up being a bolt that was somehow left in a scavenge line during overhaul.
Have you ever discussed what engine you dislike working on the most? Mine is the TF34.
Thanks for the explanation... I appreciate it
these hydraulic/mechanical fuel controllers are really cool. If you have a schematic of the internals of the fuel control you should make a video about that so that people can appreciate how complex it is even though it was made in 1955.
Absolutely stunning explanations
I’m sure it is not fun to start all of those fittings! So easy to cross thread and takes so much care!
With rigid lines, or even with the large, short hoses, getting the fittings started is the most difficult part of the job.
In early 1963, on my first placement as an apprentice, straight out of the training school, I was put into the Viper and Double Mamba build shop. After an introductory spell on the strip section, I was let loose on Double Mamba build. I got a large union nut cross-threaded, realised what I'd done, and was in the process of correcting it, when I was spotted. I was ticked off, but given credit for doing so.
Great video, I’m supposed to start school to become an A&P in May and I’m very excited. It might be pushed back though because of all the uncertainty around coronavirus☹️
Get a head start, and watch the 100 plus videos in my playlist called Your Questions Answered.
It will definitely not hurt your grades!
Thanks a lot that was awesome explanation .
Fantastic as usual. THANK YOU
thank you . your videos are awesome
Thanks very much....!
Interesting that inlet and high pressure section doesn't handle altitude compensation since inlet pressure tells you the effective altitude (air density).
Among the many other things I take away from your videos... I'm definitely more appreciative of some of the more "maintenance friendly" engine designs of the past 20 years.
Excellent video. I think temperatures controlled solenoid valve takes feedback from EGT.
Good guess.
I was wondering when we will get the test runs of the dutch starfighter foundation j-79 for the f-104
It's in the pipe. The schedule has been affected by world events...
AgentJayZ understandable thanks for the reply!
Jay, I love, and hate this old technology. All of the plumbing has been replaced by wiring. Makes me wonder what is going to be the next big step to improve control of the power output. I work on cars at a dealership for a living, but I have always been interested in aviation. I don’t know if your job pays well, but it revolves around the highest tech of the time and that is almost like being there when they were built!
I've talked to a few retired military pilots, and they all have the same list of favorite planes to fly based on fun, feel, and thrills.
In no particular order:
Supermarine Spitfire
North American Aviation P-51 Mustang
North American Aviation F-86 Sabre (actually, they prefer the Canadair Sabre 6)
McDonnell Douglas F-4 Phantom 2
All old, and all with analog engine controls.
I think I would prefer an all manual carbureted v-12 rear wheel drive roadster to a drive by wire digital fuel injected KERS hybrid with launch control and gps integrated ABS with paddle shifters.
Just me...
AgentJayZ those aircraft are some of my favorite, although I never got the chance to fly them personally. But I did get my private license. If you ever get a chance, go out to the Reno air races, they have a good mix of warbirds, Jets, and new light aircraft racing around pylons in the desert. Great sights and sounds. On a side note, is the Sabre 6 a higher powered version of the f-86?
I was at the Gold Cup in 2014, and had a pit pass. Amazing experience.
The Sabre 6 was a Canadian license built version of the F-86F, and it used a Canadian designed and built engine, that produced 7200 lbs of thrust. (Last month, one that I built made 7700)
In the F86-F, the GE J47 produced 5500 lbs of thrust.
The J47 is a great engine, with more combat hours than any other jet engine ever. The two engines are different, and you can't say that one is a higher powered version of the other.
The Sabre dominated the sky in its day with either engine.
Check out my vids of J47 tests.
"Cooler, Oil, Tubular, Aircraft ... I don't know why we say it backwards." Military method of classifying things, go from the least specific to the most specific identifying parameter.
Thanks again for your interesting videos.
Edit. Have you ever talked about EPR (Exhaust Pressure Ratio)? If that even applies.
No. EPR is a pilot, feel good thing. It's meaningless, except to give a general indication of engine operation.
I made a video called Jet Engine Thrust a few years ago. It's a bit of a rant, but it's about the fact that jet engines are not pressure devices, but acceleration devices.
I still chuckle at the question I asked back then: how fast does a hydraulic jack fly?
Here it is... it's OK if you don't like it. th-cam.com/video/BeuP2BAky74/w-d-xo.html
Thank you, I watched your link. You seemed a little pissed off. Can't say I blame you. I did say "if that applies" because I did not know.
I was thinking that about approximately 3:55 when you were talking about the difference in pressure between the two lines and I thought it may be similar.
I believe pilots set power based on the EPR. I remember their was a crash in 82 of a Air Florida Flight 90.
I believe part of the problem was the EPR sensors were iced up and gave incorrect power settings.
thanks your video is superb
Yes & thanks!
Maybe that oil cooler could be used in a laminar flow water fountain.
I might try that.
hello sir, could you please put some light (make video) on FADEC and Hydromechenical type fuel control
From California ,great vid . 102 % ? please explain how this is possible. Thank you
102% of rated rpm and power. Same thing as how cars have maximum torque at certain rpms in so called power bands.
From a previous comment:
100% is the nominal max recommended power, beyond which component life is shortened due to thermal stress.
Takeoff power is 102% of that value, and is limited to 5 minutes duration.
These are old military turbojets. I can't say if modern airliner engines follow the same rules.
blancolirio might know. He flies the 777. Check out his channel.
Hey! I agree. Our test cell tachometer reads in revolutions per minute.
Aircraft tachs read in percent... to which I say: percent of what?
You would often hear that the Space Shuttle had "throttled up to 104% rated power". Eventually they changed the rating, so that became the new 100%.
@WanJae42 No, they stuck with it to not confuse numbers from earlier testing. Emergency power was 109% and they had been tested to 111%. Now with development of SLS they have tested to 113%.
Good evening sir, I believe anything from your, very respectful video and very smart theory. I always watching and share to son, God bless you sir, hoping God always given a good health. my family loves you.
Amazing video. One quick question, I heard somewhere that the fuel:air mixture of a jet engine is far more lean that pistons, but I have a hard time wrapping my head around it. So, what is the fuel:air mixture of a jet engine and why is it different to a piston engine? Thanks a lot, your videos are very helpful
Good question, with a complicated variety of answers. I am very busy, but I want to make a video exploring the various factors.
@@AgentJayZThanks for the video, just watched it. You just made my day. Did not expect you to respond to my comment let alone make a video. Very insightful video, answered a long time question of mine. Now you got me interested in turbine blade materials and their limiting factors lol.
Agent Z...the naming convention of bendix was created for quick visual identification, stocking, ordering, ie. Your last shot of oil cooler: “Cooler, Oil, Tubular, Aircraft” correlates: “Function, System, Construction Type, Vehicle (or Final Assembly Unit)... I worked in automotive aftermarket parts in my teenage days, and believe it or not I ask that very question to a sales rep once...go figur
Awesome. Thanks. I still think the same amount of information is contained in the phrase a human being would use: vehicle, construction type, system, function... aircraft tubular oil cooler. Saves all those commas, too!
102%? That's possible? Would enjoy an explanation of that.
100% is the nominal max recommended power, beyond which component life is shortened due to thermal stress.
Takeoff power is 102% of that value, and is limited to 5 minutes duration.
These are old military turbojets. I can't say if modern airliner engines follow the same rules.
blancolirio might know. He flies the 777. Check out his channel.
Me too, how can that be ?
Is there an oil fill / air vent procedure for the fuel system? (Like on Diesel piston engines.)
I.e. if the fuel system was completely apart for servicing, is there a special procedure to get fuel back into every part of the fuel system and any air out? Preventing any air pockets?
Or is the fuel feed pressure from the boost pump in the tanks enough to get the fuel system started. I.e. Boost pump delivers fuel up to the main fuel pumps, they deliver fuel to the rest of the system and any residual air is simply (?) blown out of the fuel nozzles.
p.s. Many thanks for these in depth explanations.
Yeah, there are bleed ports on the fuel pumps, because they are the highest point in the fuel system.
I may make that part of an upcoming vid.
You could just spin the engine up on the starter, and pump about a gallon of air through it until the fuel gets there, or use the fuel bleed ports. Engineers are pretty dang smart, I tell ya!
4:30 It's smoke limitation just like on a diesel engine. Fuel quantity is limited to certain amount according to either boost pressure or air mass flow or lambda measured in the exhaust. Adjusting the limitation maps closer to actual smoke limit you will get better response of the engine.
Not a piston engine, no lambda sensor, smoke's got nothing to do with it. The compensation is to ensure thrust stays consistent as the plane gains or loses altitude, so the pilot does not have to constantly adjust the throttle during combat.
Can the burners become clogged up like a fuel injector on a car?
Possible. Most coking and deposits form at shutdown.
Thank you for the videos !
btw... I do not understand how bypass air is different from a propeller? If most of the thrust in a jet engine comes from by pass why not just have a prop plane not a jet?
A turbofan puts a greater acceleration into the air than a prop does. A 3,000 Hp piston engine once swung a 13 foot prop. An 80 thousand Hp turbofan spins a 9.5 foot fan.
Maybe it's the ducting, but also the difference in blade number.
The discharge of the fan is moving much faster than the prop wash.
AgentJayZ Hey mate, just out of curiosity - do you get many turbofans in the shop (either low or high bypass), or is it mainly the old but gold engines? Also, please forgive a very stupid question, but do you see turbofans on ground/turboshaft installations? Or is it completely pointless and I’m not understanding right? Fairly sure all of the second question is part of the answer.
Thanks in advance, and cheers from Australia.
P.S. I *really* need to send you a bigger flag one day. You know, to... compensate for things.
In high bypass turbofans, most of the engine power is harvested by the LP turbine to drive the fan. It's a fairly simple modification of the design to increase the amount of energy harvested by the LPT, and the delete the fan itself, so the LPT drives the output shaft with almost all the power created by the burning fuel.
That is exactly what GE did with the CF6 series of engines to create the LM 2500.
It started out as a 25 thousand Hp engine, and has grown to almost twice that.
Check out my LM 2500 videos!
@@AgentJayZ thank you !
thank You
Do you have any data on the temperature of the oil going into the cooler and the temperature of it when it comes out?
we measure oil into the cooler and in the reservoir (after the cooler), so yes. The oil lose about 100F.
I don't know what the flow rate or heat capacity of the oil is but that sounds like 100s of kW in heat transfer if it is 1 liter per second.
Hey, I have just subscribed! I love your videos! Now I have a question that will sound very insane ! All issues aside, which I know I will encounter many! Do you think a very skilled person can build a 500Kg thrust low bypass jet engine!!
I have no problem getting the fuel, I can do casting, CNC machining, computerised MIG welding etc...
I want to make a dream come true.
Building a turbofan engine of your own design? Whoa, that is the project of all projects.
A million times easier, but still requiring great skill and determination, would be to restore a small turbojet or helicopter turboshaft. I have several videos about designing and building your own engine.
Search box on channel page.
@@AgentJayZ Thanks for coming back to me. Actually my only huge concern would be oil sealing, due to the temperatures involved. I have already gathered some precious information. I was thinking about a fearly simple twins pool turbofan. I already have designed most of the main parts and now learning about powder 3D printing and wax molding... My actual headache is about the injectors design. I think I'm going crazy but in a good way 😂🤣.
02:30 Sir, what material is used for the fuel injection pipe? whether using copper? or steel?
Stainless steel.
@@AgentJayZ thank you sir 🤗
Oil cooler, so it's different from FOHE (Fuel Oil Heat Exchanger), that is mentioned to heat cold fuel and melt possible ice crystals. And hot engine oil is used to heat fuel?
Both things happen, because its a heat exchanger. But the manual calls it an oil cooler.
If anybody wants to call it french toast, that's fine with me... just not in my shop.
If I am intepreting right the F-86 cutaways available, the manual (as quoted by Jay) calls it the right thing. In this ship the fuel tanks are inside the fuselage and so are not exposed to cold soaking as it happens in airliners fitted with integral fuel tanks built as part of the wings. In the Saber, the only fuel exposed to the external air temp. would be the one inside the drop tanks, but I doubt even this fuel would have the time to get too cold, as the drop tanks will be the first to get depleted. So, IMHO, the main function of the oil cooler is indeed to cool down the oil, the heating up of the fuel being a welcomed by-product, but not as critical as in an airliner. Great video, by the way!!
I don't know why there is such consternation, analysis, and unnecessary debate.
Orenda built the engine, and they call it an oil cooler.
All comments on the subject are useless, irrelevant, and a complete waste of effort.
These are the facts, and the facts don't give a shit what anybody thinks.
OK, then?
RB211s used to have FCOCs (fuel cooled oil coolers): it appears that Trents now have FOHEs (fuel/oil heat exchangers). There is essentially no difference: they perform exactly the same function.
Does the 1-to-6 fuel distribution block ensure the same fuel flow to each fuel nozzle or does it modulate the flow to each fuel nozzle based on how rich/lean that particular combustor can is burning?
I believe the fuel distribution blocks function is to flow the same amount of fuel to each nozzle regardless of differences in resistance.
My instinct is that their is a fixed displacement mechanism (Probably similar in form to a gear or vain pump) for each burner. These "pumps" would not necessarily be driven mechanically but by the flow of fuel through them. If each fixed displacement device where attached to each other by a shaft, then each output would flow the same amount of fuel regardless of the resistance experienced at each output.
No such thing as rich or lean. It evenly divides the flow into six separate lines.
Maybe you could show how you receive and ship these Turbojets engines.
ratride1 One was shown recently being in a container on a mattress :)
There's a search bar on my channel page. Try "engine shipping containers"
Thanks, i was kind of thinking this is the case.. But wanted to ask if there would have been some differences. Thanks for the great and fun answer AgentJayZ!
AgentJayZ Thanks I’ll check that out.
Do you ever prepare engines for long term storage before shipping them back?
What kind presure does the fuel system run at.
This one? I think I said it was 600 to 1100 psi. Maybe that was in the previous video.
@@AgentJayZ thanks
Thanks
sir is that shaft 01:34 moving by throttle activating from cockpit?
so if we want to increase speed, we have to push the throttle on cockpit right?
That lever, as well as the one on the emergency fuel control, is connected ( by the green rods) to a pivot which is connected to a cable that goes to the throttle handle in the cockpit. You can see the throttle handle in a video I made comparing the start sequence in the jet and in the test cell.
How do designers determine what fuel a gas turbine engine will use and why? (kero vs jet a vs etc)
JetA is the design fuel. Kerosene, diesel, are interchangeable with minor adjustments. AvGas or any gasoline is a suitable alternate fuel with minor adjustments and shortened service life for fuel system components.
In a pinch, if it burns, it turns.
Please tell the material also from which parts are made from 🔰
Each part is made of the most suitable material. Not making a list. You need to be more specific.
Also: I put the things together; I don't really need to know what they are made of.
That oil cooler looks like it might make for a mighty fine dephlegmator
Bonus pints for the correct spelling of phlegm... or is it flegm now?
And remember to never dispose of the contents of the dephlegmator in the re-bigulator.
what kind of fuel injector engine use? pressure swirl?
I presume there's an important reason why fuel reaching the dump valve -- and subsequently dumped or captured -- should never be poured back into a fuel tank?
The usual amount dumped out is about 500ml, or a pint. This engine uses between 2 and 20 gallons per minute in operation.
Also, the system was designed in the 1950s for a military fighter.
The amount wasted is an insignificantly small quantity.
Was the Orenda 10, 11, or 14 ever fitted with an afterburner/reheat?
I've heard rumors of an afterburning Orenda 17, but never seen one, or seen any reference to one in a manual.
here is the video that AgentJayZ was refering to at 16:05
th-cam.com/video/5fRBOkXvAK0/w-d-xo.html
Did you get that drip to stop after filming the video?
Did
Does the fuel system require bleeding after maintenance? thanks in advance!
Any removal from active service, for whatever reason, requires complete "reactivation" service of the entire aircraft. All systems checked, fluids topped up and bled.
@@AgentJayZ many thanks, Id be curious to see more details of a reactivation service if its something youre ever able to cover in a video, no worries if not though and thanks for the response
Whatever day it is, it's the _next day._
❤️
I like models copy's of the real thing like my M67, but like that oil cooler with words all back to front, this thing says grenade, hand, frag, delay, M67
👍🏼
you got a fuel leak there fella! oh nvm u know
Leak at 55 seconds! Drip Drip from it's tip!
Yes. All those little details get taken care of while the pre run testing is done in the test cell.
20th viewer
I hate your videos Jay. I can't simply play them as background noise as they always draw my attention away from whatever it is I'm doing at the time.
I try to make them more of a source of information, and I try not to compete with the more entertainment-oriented channels.
Sorry.
Yepp, can't watch them casually, have to pay attention :-)
That's a fuel heater eh.
The FCOC ? Nope, it's main purpose is to cool the oil (sure the fuel gets heated in the process, but it's not the main goal)
I love you and your videos, but please stop wearing that hat.
Different hat every day. Only option: old bald head.
AgentJayZ From a fellow bald guy, that’s a badass hat, Jay. Wear that thing proudly. greetings from Iowa, USA.
@@AgentJayZ I wouldn't mind. Whatever keeps you happy enough to keep sharing info is fine with me, I suppose.