These actuating rings are almost as cool as the after burner actuators. Your videos have shown me the coolest mechanisms I've ever seen. Thanks for sharing your work with us.
You got lucky! I don't think the *Metallic Sea Monster* was dead at 7:00. I'm pretty sure it was just taking a nap. Again, thanks for sharing all these cool contraptions with us.
This isn't a job for anyone with NO PATIENCE. You make it look so simple. And thanks for no music and or drama like reality TV which SUCKS. I learn stuff this way much better.
This is really good viewing. I have worked in power generation for 24 years, both nuclear and gas turbine. Our turbines are designed for torque (from 176MW to upwards of 240MW). Really cool to see a small power turbine with the same types of tolerances. Good stuff. We also (obviously) have IGVs. However, we do not have the stages 1-3 variable stators. It would be really awesome to talk to you or one of your guys. I'm a Controls Specialist, so I have to tune our CTs regularly. Good stuff to see..
Man I'm over here in London England and started watching these videos randomly.. I guess I have an interest in aviation... anyhow I'm totally hooked on these videos now. Particularly the .... a closer look vids. Thanks for taking the time to make and post these videos. I've learned a lot.
Hey! Thanks... The Closer Look series are my most numerous, and they are a chance to look at things "hands on" in gas turbine engines. My Jet Tech series are less common, because they are harder to make. They are intended as real training videos, to demonstrate a procedure in detail that one might encounter as a gas turbine technician...
Thanks Jay! Nice to see everything on a smaller scale! Funny that you're rebuilding a heli turbine as we've got two Super Puma's at the local aerodrome for a few months working on a new 440 kv distribution network in the region. We normally only have light aircraft and microlights in the circuit above my house...! It's nice to have some 'insider' knowledge...! Thanks for all the hard work you put into showing us all what happens behind normally closed doors. Rich, France.
What a nice little engine! Very nice to work on indeed, I can imagine. I would love to get my hands on such an engine one day. Great videos btw! Keep it up! Very entertaining, but most of all very, very educational!
Thanks for the vids they are absolutely awesome! Also, thank you for answering that question about concentricity I was wondering the definition myself.
The white connector in front is for the starter leads. The VSV system is controlled using signals for engine rpm and mass air flow. The actual sensors are for engine rpm and inlet air temp.
They are attached to a spline on the end of a shaft that protrudes outward from each vane. The shaft passes through a bushing in a hole in the compressor case.
Servo is a word bandied about by many (including me) without really seeming to have a full understanding of its meaning. So I looked it up: "an electronic control system in which a hydraulic, pneumatic, or other type of controlling mechanism is actuated and controlled by a low-energy signal. " By this definition the VSV system does seem to be a servo system, except for the electronic part.
Seeing all that (steel?) stuff line up nicely and move so smoothly makes me feel fuzzy wuzzy tingle times. Such gentle precision for a roaring beast of a thing (even though I know it's a small one). Awesomeness!
AgentJayZ the test?! Is there really one? But i already have too many interests and hobbies AJZ - i don't need to find out i have yet another passion! On a more serious note: i had very little idea about how any of these systems worked previously. But after watching many of your vids i feel really well informed and have a really good grasp of stuff. I was even explaining it to my wife yesterday! Thanks so much for all your hours (hundreds?) of content. Amazing resource of detailed information. Hopefully preserved forever in digital space for all and anyone to absorb.
Ever consider doing a video on how the lube system works in a turbine? I know a large corp. here that insisted on installing their own backup powerplant. Evidently they filled some oil reservoir with nice turbine oil but did not know there was a plastic liner in the tank that should have been peeled off and I guess you know the rest when they fired it up the first time. hehhehheh
Ahh you mentioned a curvic coupling. An amazingly great system of aligning cylindrical components. Where else in aircraft applications do you see them? I've come across them in cnc lathes, where parts have to reposition within .0001" repeat ability.
great video, Jay, just want to know if you have a video to explain how does the servo/control section inside of main fuel control work to use fuel to control VSV on LM2500. thanks
yeah... I don't know what special magic is inside the fuel control, but it senses air temp, inlet pressure, and engine rpm. The VSVs are moved by a hydraulic actuator fed fuel pressure from the fuel control. There's no computer.. not even any electricity involved in the VSVs.
Are those the same heim joints/rod ends/spherical bearings that came out of the engine? Do you use the teflon-lined joints or are they metal/metal? Thanks for taking the time to make these videos.
I got out of this 20y ago. 90mph in a Class B was good. Now....it's a rich man's game. Next time the worlds are back in NZ I'll make an effort to go have a look. Yes Yes I know a 800+ hp V8 ain't cheap either.
Im a huge ratchetting wrench fan.. where they fit. I always wonderd why they had never made a weaker but narrower wratchetting wrench. Not necessarirly to put any real pressure like 10 ft pounds on them, but just to get the threads started and snug. Then switch to a wrench to tighten the bolt that half turn or so left over. Besides, probably need to do that with a torque wrench anyway.
Jay thanks for the vid. What would happen if this was an aircraft engine and the variable stator system failed or got stuck? Would it cause the engine to flame out or would it still run but with reduced power (maybe like a misfire on a car?)
Not sure you covered it earlier, but what is the purpose of the IGV and variable stators? Is it to lower the compression to unload the shaft to ease spinning it up to RPM or the opposite, to increase compression, so that the combusters get the needed amount of compression before it is at operation RPM....or is it something else entirely?
Is the control of the IGV and stators pre programmed acording the RPM by something like a table during the design of the engine ? or there is any sensor, like pressure, that is involved in the control ? What is that white 2 banana plug in the front? is the RPM sensor?
Hahaha i watched part 1. Race Boat Engine. That's answered that question nearly, but how do you turn that turbine from sucking in air to the boat pushing out water? and the jet ski's?
Hi Jay, I read 'way down' the comments list & saw several questions regarding the control of the VSVs. You mentions MAF & RPM as inputs to the system but since this is older technology, I am assuming there is no 'computer'. Is the system lube oil powered, using mechanical sensors & regulators to control/move the actuator? Thanks again!! Darren
I have a question, not really based on your video but the back ground of your workshop. You have a couple of jet ski's and a powerboat? Do they run on turbines? Like water turbines that run of normal turbines? Is that why you have them or are they a hobby of yours or??? Sorry to be nosey and sorry to sound dumb!
Jay, i have a curiosity, the actuator rings, do they ride on any sort of bearings? When you move them, the sound like metal/metal contact, a mild gritty sound. It would be surprising if they are how it appears, i would think dirt contamination would be a problem.
Neither. The system manages the effective angle of attack of the larger compresor blades. Like mini-wings, at lower speeds they can stall. When this happens they lose efficiency at moving air backward, and the air in the stages behind them is able surge forward. This causes a banging noise, loss of power, incorrect fuel-air ratio with resulting flames being visible, and vibration.
Jay, I have a question: most cars, after being driven very hard (say, for example, a circuit), need to be left idling for a few minutes for the oil to return to a safe temperature so when you turn it off it won't degrade, coke and block passages or lose it's properties. Does the same apply to gas turbines or ar they safe to shut down right after a full throttle run?
The oil is good for extremely high temps, but a couple minutes cooldown really helps reduce the possibility of cracks happening in the hot parts, like stg 1 turbine nozzles and blades. Jet oil is very low viscosity, so if you put it in your car, bad things will happen...
Kindly can some unswer me for the following question:In a turbine engine In order to create pressure in to the combustion chamber , the compressor has to introduce air in the combustion chamber more than can come out from the exhaust side to create stagnation pressure, since the eshaust side is always open to ambient pressure , not like ICE where there are valves ?
I think you need to obtain one of the many great introductory books about gas turbine engines.. and then read it. Also, you must not try to compare these engines to piston engines. They are very different.
A flight-worthy T-58 is easy to find. Minimum price: a couple hundred grand. The trick is to find a surplus, timed out engine of questionable history. Price? Who knows... Then you send it to me, and I make it work for you. If you are looking for one of the latter, you are competing with me. All I will tell you is it takes some work and some luck to find one.
seems very complicated compered to bleed valves, that would not work or is there some other reason to chose one over the other? as far as I can tell from an old paper on the engine they are fully open and don't move at normal operation speed
The purpose of either system is to prevent aerodynamic stall of a compressor with aggressive geometry that allows high performance, but which would stall without some sort of help at lower rotational speeds. Both bleed valves and variable stators perform this function well.
@@AgentJayZ I understand that, I have been paying attention in your class ;) Just seems strange to choose what looks like much more complicated system with lots of intricate moving parts over some valves if doesn't offer some advantage in normal operation
Thanks for the info. So it uses the fuel system as the fluid source... I reckon that the fuel control should know what the VSV's should be doing, given throttle setting, etc. I find this stuff fascinating! DD
All modern engines have vsvs.. almost. What you need to do is read up on what vsvs, or variable geometry are for in a turbine engine. I have covered this subject several times in my Your Questions Answered playlist. There is an index and search bar.
Sorry but what does the Variable Stator System do ?? i know the hydrolic moves those stator but then for what... pardon me for missing out some explanation.. thanks have a good day.
Can anyone help answering a question? Why vsv or vigv actuators use “high pressure fuel” for operation? Does it has to be high pressure fuel to do the job?
The actuators are hydraulic cylinders, which need pressure to work. 400 psi fuel is not exactly high pressure, but whatever. The VSVs are controlled by the fuel control directly, instead of having an intervening system being controlled by the fuel control and modulating oil or hydraulic fluid to move the actuators. It's in the interest of simplicity and more positive control.
Thanks, I thought that's related to some physical characteristic of fuel which allows a better control, but does it also introduces a risk of fuel leakage in the actuator with this design?
Once there is noticeable looseness or separation of movement, they should be replaced. There is a bit more leeway when inspecting an engine destined for powering a boat compared to one used in a helicopter.
What is the Stator do in a jet Engine..? I am a two stroker guy, and know wery little about jet Engines..But i am wery interested in dhoes Huge Hairdryers....!
Jet ski's, to hell with the jet ski's. I couldn't find much of anything on ebay, most of it is books and pictures, kid of useless, like jet ski's. Where would there be a good source to find these engines used and clean?
These actuating rings are almost as cool as the after burner actuators.
Your videos have shown me the coolest mechanisms I've ever seen. Thanks for sharing your work with us.
At 5:55 "I hope you are too". Yes, I'm very pleased and a bit surprised they went together so easily. It was fun to watch.
You got lucky! I don't think the *Metallic Sea Monster* was dead at 7:00. I'm pretty sure it was just taking a nap.
Again, thanks for sharing all these cool contraptions with us.
This isn't a job for anyone with NO PATIENCE. You make it look so simple. And thanks for no music and or drama like reality TV which SUCKS. I learn stuff this way much better.
Concentricity also defines the state of my brain when watching your videos. Thanks for showing us how you work on turbine engines.
How COOL is this!?! At 57 yrs old, I now know what concentricity means! :)
Extra point for spelling it correctly. Two, actually.
This is really good viewing. I have worked in power generation for 24 years, both nuclear and gas turbine. Our turbines are designed for torque (from 176MW to upwards of 240MW). Really cool to see a small power turbine with the same types of tolerances. Good stuff. We also (obviously) have IGVs. However, we do not have the stages 1-3 variable stators. It would be really awesome to talk to you or one of your guys. I'm a Controls Specialist, so I have to tune our CTs regularly. Good stuff to see..
Jay: this is real reality TV.
Man I'm over here in London England and started watching these videos randomly.. I guess I have an interest in aviation... anyhow I'm totally hooked on these videos now. Particularly the .... a closer look vids. Thanks for taking the time to make and post these videos. I've learned a lot.
Hey! Thanks...
The Closer Look series are my most numerous, and they are a chance to look at things "hands on" in gas turbine engines.
My Jet Tech series are less common, because they are harder to make. They are intended as real training videos, to demonstrate a procedure in detail that one might encounter as a gas turbine technician...
Thanks Jay! Nice to see everything on a smaller scale! Funny that you're rebuilding a heli turbine as we've got two Super Puma's at the local aerodrome for a few months working on a new 440 kv distribution network in the region. We normally only have light aircraft and microlights in the circuit above my house...! It's nice to have some 'insider' knowledge...! Thanks for all the hard work you put into showing us all what happens behind normally closed doors.
Rich, France.
This is by far the coolest, most informative video I have seen in a long time. Thank you Jay.
Never seen it, but I have heard about it. A very rare event.
What a nice little engine! Very nice to work on indeed, I can imagine. I would love to get my hands on such an engine one day.
Great videos btw! Keep it up! Very entertaining, but most of all very, very educational!
Thanks for the vids they are absolutely awesome! Also, thank you for answering that question about concentricity I was wondering the definition myself.
They ride on hidden rollers as you suggested. They are held in place by sliding in grooves that are highly tolerant to contamination by design.
Sea monster and a very cool set of needle nose pliers!
You are cool man..
The white connector in front is for the starter leads. The VSV system is controlled using signals for engine rpm and mass air flow. The actual sensors are for engine rpm and inlet air temp.
See AJZ gets near a boat and starts seeing engine parts turn into "metallic sea monsters" with tentacles. At least there are no gremlins. =D
Like reality TV.... except this is interesting to watch and actually very good!
I think those needle nose pliers you were using are cool. Also like how you make something that looks so complicated go together so easily.
They are attached to a spline on the end of a shaft that protrudes outward from each vane. The shaft passes through a bushing in a hole in the compressor case.
Once again awesome!
Thank you!! Great video!
Thank you very much for explanation!
You Sir are a legend!
The shop is the home of the boat, and I'm working on-site as a guest.
All I know about the other vehicles is that they are all modified to go faster.
Thank you sir..Your are cool.Love from India
Another Great Video, Thanks.
Awesome video ,cheers !
Yeah it's just like reality shows.. except it's not boring and stupid, but exciting and educating ;)
I'm always amazed this tiny thing makes 1200+ HP.
They are specific parts made for this engine. The spherical beaings do not contain anything that could melt.
very very intresting!!!!! thanks a lot!!!!
There's actually a line in the overhaul manual that reminds you about them.
Thanks !
Servo is a word bandied about by many (including me) without really seeming to have a full understanding of its meaning.
So I looked it up:
"an electronic control system in which a hydraulic, pneumatic, or other type of controlling mechanism is actuated and controlled by a low-energy signal. "
By this definition the VSV system does seem to be a servo system, except for the electronic part.
Seeing all that (steel?) stuff line up nicely and move so smoothly makes me feel fuzzy wuzzy tingle times. Such gentle precision for a roaring beast of a thing (even though I know it's a small one). Awesomeness!
Seems you have a precision mechanical fetish... might be a gearhead. You should take the test...
AgentJayZ the test?! Is there really one? But i already have too many interests and hobbies AJZ - i don't need to find out i have yet another passion! On a more serious note: i had very little idea about how any of these systems worked previously. But after watching many of your vids i feel really well informed and have a really good grasp of stuff. I was even explaining it to my wife yesterday! Thanks so much for all your hours (hundreds?) of content. Amazing resource of detailed information. Hopefully preserved forever in digital space for all and anyone to absorb.
+Andre Gulbis
I made a video called "are you a gearhead?"...
Oh! OK - will have a look-see.. thanks!
hurbs thanks for the details answer.
No flame out, but reduced power if they were stuck closed, and a horrendous amount of banging and popping when throttling down if stuck open.
"Almost like reality TV"... yeah, except that this is interesting :-)
Sehr interessantes Video.
Can't wait for the next one! Quick question, what kind of connection does the little arms have that allow them to move like that?
Basically I was trying to explain what that means.
Thanks you so much.
Ever consider doing a video on how the lube system works in a turbine? I know a large corp. here that insisted on installing their own backup powerplant. Evidently they filled some oil reservoir with nice turbine oil but did not know there was a plastic liner in the tank that should have been peeled off and I guess you know the rest when they fired it up the first time. hehhehheh
This was answered yesterday, so take look about six inches down the list...
Ahh you mentioned a curvic coupling. An amazingly great system of aligning cylindrical components. Where else in aircraft applications do you see them? I've come across them in cnc lathes, where parts have to reposition within .0001" repeat ability.
great video, Jay, just want to know if you have a video to explain how does the servo/control section inside of main fuel control work to use fuel to control VSV on LM2500. thanks
yeah... I don't know what special magic is inside the fuel control, but it senses air temp, inlet pressure, and engine rpm. The VSVs are moved by a hydraulic actuator fed fuel pressure from the fuel control. There's no computer.. not even any electricity involved in the VSVs.
Are those the same heim joints/rod ends/spherical bearings that came out of the engine? Do you use the teflon-lined joints or are they metal/metal? Thanks for taking the time to make these videos.
I got out of this 20y ago. 90mph in a Class B was good. Now....it's a rich man's game. Next time the worlds are back in NZ I'll make an effort to go have a look. Yes Yes I know a 800+ hp V8 ain't cheap either.
Thanks verry mush maann
Im a huge ratchetting wrench fan.. where they fit. I always wonderd why they had never made a weaker but narrower wratchetting wrench. Not necessarirly to put any real pressure like 10 ft pounds on them, but just to get the threads started and snug. Then switch to a wrench to tighten the bolt that half turn or so left over. Besides, probably need to do that with a torque wrench anyway.
I agree with you, and wish such a thing existed.
Jay thanks for the vid. What would happen if this was an aircraft engine and the variable stator system failed or got stuck? Would it cause the engine to flame out or would it still run but with reduced power (maybe like a misfire on a car?)
Thanks for the reply as always. Have you ever known them to fail?
What engages the Hydraulik - cylinders to move them ? Dependance it only by the thrust - Lever ?
Not sure you covered it earlier, but what is the purpose of the IGV and variable stators? Is it to lower the compression to unload the shaft to ease spinning it up to RPM or the opposite, to increase compression, so that the combusters get the needed amount of compression before it is at operation RPM....or is it something else entirely?
Do 3 spool engines have vsv? Like RB211? Because i heard they dont need them since they run at their optimum speeds.
The IGV Hydraulic actuator, is that a Servo or part of a Servo system rather???
Another Great Video!!!
Is the control of the IGV and stators pre programmed acording the RPM by something like a table during the design of the engine ? or there is any sensor, like pressure, that is involved in the control ?
What is that white 2 banana plug in the front? is the RPM sensor?
Give This Guy a Google Glass!!!
Hahaha i watched part 1. Race Boat Engine. That's answered that question nearly, but how do you turn that turbine from sucking in air to the boat pushing out water? and the jet ski's?
coooooooooooooooooool
Hi Jay,
I read 'way down' the comments list & saw several questions regarding the control of the VSVs. You mentions MAF & RPM as inputs to the system but since this is older technology, I am assuming there is no 'computer'. Is the system lube oil powered, using mechanical sensors & regulators to control/move the actuator? Thanks again!!
Darren
I have a question, not really based on your video but the back ground of your workshop. You have a couple of jet ski's and a powerboat? Do they run on turbines? Like water turbines that run of normal turbines? Is that why you have them or are they a hobby of yours or??? Sorry to be nosey and sorry to sound dumb!
I bet if you wrapped a spring below the IGV's it will help the start in the ring.
Jay, i have a curiosity, the actuator rings, do they ride on any sort of bearings? When you move them, the sound like metal/metal contact, a mild gritty sound. It would be surprising if they are how it appears, i would think dirt contamination would be a problem.
almost like reality tv...
this is nothing like reality tv. this is actually real.
Neither. The system manages the effective angle of attack of the larger compresor blades. Like mini-wings, at lower speeds they can stall. When this happens they lose efficiency at moving air backward, and the air in the stages behind them is able surge forward. This causes a banging noise, loss of power, incorrect fuel-air ratio with resulting flames being visible, and vibration.
I was thinking that on disassembly. So I left them in there with their nuts attached.
... Honest - there is no intentional joke there...
i wonder how many people forget those 2 bolts that hold the hydraulic actuator when they were putting the IGV actuating ring on lol... hate that
Jay, I have a question: most cars, after being driven very hard (say, for example, a circuit), need to be left idling for a few minutes for the oil to return to a safe temperature so when you turn it off it won't degrade, coke and block passages or lose it's properties. Does the same apply to gas turbines or ar they safe to shut down right after a full throttle run?
The oil is good for extremely high temps, but a couple minutes cooldown really helps reduce the possibility of cracks happening in the hot parts, like stg 1 turbine nozzles and blades.
Jet oil is very low viscosity, so if you put it in your car, bad things will happen...
AgentJayZ didn't even crossed my mind to put it in my car, don't worry :)
Lol, they're watching this video in the other class at my school right now
Tell your instructors if they send me school swag, I'll feature it in a video...
Kindly can some unswer me for the following question:In a turbine engine In order to create pressure in to the combustion chamber , the compressor has to introduce air in the combustion chamber more than can come out from the exhaust side to create stagnation pressure, since the eshaust side is always open to ambient pressure , not like ICE where there are valves ?
I think you need to obtain one of the many great introductory books about gas turbine engines.. and then read it.
Also, you must not try to compare these engines to piston engines. They are very different.
A flight-worthy T-58 is easy to find. Minimum price: a couple hundred grand. The trick is to find a surplus, timed out engine of questionable history. Price? Who knows... Then you send it to me, and I make it work for you.
If you are looking for one of the latter, you are competing with me.
All I will tell you is it takes some work and some luck to find one.
basically to prevent a compressor stall :)
seems very complicated compered to bleed valves, that would not work or is there some other reason to chose one over the other? as far as I can tell from an old paper on the engine they are fully open and don't move at normal operation speed
The purpose of either system is to prevent aerodynamic stall of a compressor with aggressive geometry that allows high performance, but which would stall without some sort of help at lower rotational speeds.
Both bleed valves and variable stators perform this function well.
@@AgentJayZ I understand that, I have been paying attention in your class ;) Just seems strange to choose what looks like much more complicated system with lots of intricate moving parts over some valves if doesn't offer some advantage in normal operation
Thanks for the info. So it uses the fuel system as the fluid source... I reckon that the fuel control should know what the VSV's should be doing, given throttle setting, etc. I find this stuff fascinating!
DD
I wouldlike to know Why the stator blades are variable and not fixed in this engine ?
All modern engines have vsvs.. almost. What you need to do is read up on what vsvs, or variable geometry are for in a turbine engine. I have covered this subject several times in my Your Questions Answered playlist. There is an index and search bar.
Sorry but what does the Variable Stator System do ?? i know the hydrolic moves those stator but then for what... pardon me for missing out some explanation.. thanks have a good day.
How that ring is made to rotate? hydaulic or electric motor?
The VSV rings are moved by a hydraulic actuator. The working fluid is fuel in this system.
Can anyone help answering a question? Why vsv or vigv actuators use “high pressure fuel” for operation? Does it has to be high pressure fuel to do the job?
The actuators are hydraulic cylinders, which need pressure to work. 400 psi fuel is not exactly high pressure, but whatever.
The VSVs are controlled by the fuel control directly, instead of having an intervening system being controlled by the fuel control and modulating oil or hydraulic fluid to move the actuators.
It's in the interest of simplicity and more positive control.
Thanks, I thought that's related to some physical characteristic of fuel which allows a better control, but does it also introduces a risk of fuel leakage in the actuator with this design?
what are the play tolerances in these linkages?
Once there is noticeable looseness or separation of movement, they should be replaced. There is a bit more leeway when inspecting an engine destined for powering a boat compared to one used in a helicopter.
It would kinda suck to have forgotten to put in the screws at 8:09
Don't u say black 🤣😂🤓 thanks love this channel.
What is the Stator do in a jet Engine..? I am a two stroker guy, and know wery little about jet Engines..But i am wery interested in dhoes Huge Hairdryers....!
Ever consider watching my video about turbine engine lube systems?
What about fuel line systems? The 50' raceboat MISS GEICO and the 50' pleasureboat Passion both burned up when their fuel lines failed.
:D
Um looks like an Alison 250 is more in line. And when American money is actually worth something, north of the boarder.
Hi
Jet ski's, to hell with the jet ski's. I couldn't find much of anything on ebay, most of it is books and pictures, kid of useless, like jet ski's. Where would there be a good source to find these engines used and clean?