Air-Cooled Blades - Turbine Engines: A Closer Look
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- เผยแพร่เมื่อ 1 ม.ค. 2012
- A look at the hardest-working parts in a large industrial gas turbine engine, and how they compare to their counterparts in the large aircraft jet engine from which they are derived.
- ยานยนต์และพาหนะ
Thank you for showing us the real stuff which they don't teach us even in schools.
@poppopscarvinshop Some of the larger holes in the leading edge and tip are made with a laser, and the trailing edge holes by EDM. Manufacturing processes vary, and I would expect some blades have all their holes done with EDM. I don't make blades, so there are definitely other people who know more about it.
@memadmax69 The air leaves the HP compressor at over 600 degrees F, but it is still used as cooling air for the turbines, which need to be cooled to below about 1100F.
The actual flame temp is probably between 2500 and 3000F.
@Blackmoonempire There is no filtration for inlet air on aircraft engines, but the industrial units usually run with very large inlet filter/silencers.
Canada switched from imperial to metric officialy in 1978, and the process continues.
Many of us freely interchange with both systems.
I use 2.54 cm per inch, and 2.2046 lbs per kg. ( well, that's if I have a calculator handy)
@saxonlight Each unit of each pair of airfoils that make up a twin-shank element is worth a couple thousand dollars.
I believe the hole are either EDM machined. or drilled with a laser.
every time i watch one of your new uploads i am blown away by the intricacy and thought going into every little piece of the engines
dude the engineers are so incredibly smart and resourceful..
More awesomeness! Thanks for taking the time to do this!
Sweet mother of acceleration! Thanks for posting I'm enjoying learning from your videos.
Thank you man! thanks for taking a time to do an post this amazing video.
Wow, I never knew the blades for turbine engines are such highly engineered. You are truly an expert.
Thanks a lot, Bareth from Tanzania, this is the only place on earth where I can get full of information about jet engine and how they work detail by detail...Nice Job, I wish I could be there working with you..
Your content and delivery is as brilliant as the engineering itself. Enjoying every second of it.
Great video! Keep making these!
Thanks
@Bouregard3 Yes, but the turbine wheels are too large and heavy to get into our glass-bead machine. And the blades have passages which can become blocked with blasting media. The technique can be used, but then each blade reeds to be carefully cleaned and inspected to ensure all of the cooling air hole are clear.
awesome pieces of engineering,awesome video as always Jay and happy new year!
@Xandr128 Excellent to hear from someone who is running these in service ! Thanks for the info.
So awesome! Thanks for sharing, I've been waiting to see one of these cruise through the shop! Finally! Hope you had a great holiday, happy 2012.
Dear AgentJayZ:
I have watched many of your videos.
You deliver a good combination of information, overview, experience, patience, and occasional prickly responses to viewers.
This video gives me an exceptionally strong feeling that I am present in the lab with you, and that I have hands on the blades, and that I understand what you understand.
These are wonderful educational videos for geeks.
Without doubt you will draw people into your profession.
Many more will relish your sharing, and feel richer for your efforts.
Have you considered cutting a DVD and selling it?
I would pitch some to support the publishing effort.
Great thanks....
A DVD? YGBFKM! I have about a Terabyte of video posted. I could send you a hard copy of all of it to you.. in a truck, with a small deposit.....10 Gs oughtta get you started...
TH-cam made a video about just such an idea a year or two ago...
AgentJayZ Every jet engine makes a grumble sound when starting up, just right after fuel ignition. It only makes that sound for a second or 2. What is that sound exactly and why doesnt that last longer since the spooling time is much longer
I just got a pair on cf6 first stage blades off eBay for £5.50!
Can't wait to have a closer look!
Many thanks for the video
Very nice. Thanks for sharing!
Hello Jay, thank you very much for this video and I wish you a happy new year!
Thank you so much for this piece of information .
How they manufacture those blades is incredible in super tough metals. I'm impressed!
Love your videos. It's hard to sit there and talk to yourself when making them. :-)
@aftp8765 Because of the extreme heat in which they work, and the huge loads imposed on them, turbine blades are always built from high-nickel alloys.
They are very heavy, but that's the way it goes... no other material would survive.
Titanium alloys would melt and catch fire, and ceramics don't yet have the resistance to cracking and fracture.
Ingenious stuff !
Amazing, thx for the vid!
GREAT videos!
SUBSCRIBED! LOVE your videos! I work with aircraft parts and this helps sooo much!
@sharrynuk The brush is stainless steel, which is softer than the parts. If we were to use something harder than the part, like a file, we could scratch the surface. These scratches would become points of stress concentration, and points of potential crack formation in these highly stressed parts.
Nice video!
Dear Agent Jay Z, I am Santosh Gajurel from Nepal. I am doing Master in mechanical engineering from Kathmandu university, Nepal. It is my final year and I am doing my thesis on Design and thermal analysis of gas turbine blades. I found this video very helpful. I am looking forward more video regarding gas turbine.
@MoowChair Yes, that sounds about right. I did it with a simpler equation and I got 23.7 metric tons... per slot in the turbine wheel... while it's glowing red hot.
Please ensure your seatbelt is firmly fastened...
You make me get back to the mid 90´s! Remembered my good times at the Mechanical Engineering degree course. Your vids show in the real life what we used to see in the books and labs. I'm recomending your videos to a friend who teaches thermal systems at the UNiversity, are you ok this ? Thanks for sharing this interesting and unknown "behind the scenes" part of our lives, after all from times to times all of us are transported by at least two of these machines.
You are right. Bleed air sometimes piped outside the engine, and reintroduced into the turbine entry guide vanes, sometimes transmitted inside the hollow main shaft and introduced into bearing sumps.
The hole in the blades are sometimes cast in, sometimes EDM machined, sometimes drilled by laser, and newer techniques are emerging.
Takes a long time, which is one reason the blades are so expensive.
thank you very much. this is very useful information for me.
Very informative as usual. I'm fortunate to have one of these air-cooled turbine blades somewhere at home. It has cooling holes and is from an RB199. I think it's a first stage turbine. Mind-blowing to hold it in your hand and think it alone generates/ handles something like 200 horsepower.
Those blades a pieces of art.
Another video reviewed! Cool.
Darren
@zero00tolerance You may have been looking at a turbofan engine in which the fan rotates in the opposite direction to the core. I don't know off-hand of any engines that employ this, but I know some models have been designed this way.
that is some amazing engineering when you consider what goes into each little part
Happy new year, and thanks for another great "A Closer Look" - Video!
Does the air that passes the cooling holes in the turbine blades get filtered in any kind? The holes look pretty small, so that sand particles or something can block them...
And another question... Which unit system do you use in canada? I was surprised to hear the unit "meter" and "gram". Here in germany, we know nothing about inches, as rule of thumb i always divide or multiply by 2.5 :)
Hehe, I'm studying jet engines right now and I must say that watching your videos are a great aid in understanding what is explained in the book! :D How about a video about the fuel control and lubrication system? :D
Fabulous videos about fabulous engineering. I would bet schools might kill to have you teaching their students.
@sharrynuk When you attempt to prevent air from leaking through the interface between a stationary surface and a moving one, there is never a complete seal, but a controlled restriction to flow. The greater the pressure difference accross the interface, the more resistance to flow or leakage is required to minimize that leakage.
You mentioned in a previous video about turbine blade cooling that surpentine cooling was an evolution on the single pass cooling blades. But I don't understand. Passing air in a longer path would just get the air heated up more thereby reducing it's ability to cool. Seems like single pass would be better in my mind. What am i missing?
The modern engines have ceramic coated blades, but the older stuff we work with use uncoated blades. Ceramic coatings can be applied to the older engines, though.
I just found your channel. You are a great host and great at explaining the inner workings of these wonderful engines. I noticed that the compressor blades are all pitched in the same direction, but the turbine blades alternate. Why is that? Maybe you covered that previously, but I haven't seen it yet.
@lazystart We really don't have the volume to justify that sort of equipment. We do our cleaning the old fashioned way.
thnks for sharing....
Great channel, cant wait next videos... After christmas break were starting with erection of 160MW gas turbine in combined cycle power plant, its slightly bigger than these featured in yours videos :) Keep the good work ;)
9:29 The seal you are talking about looks like a face groove, after all the blades and baffles are installed. Is there a corresponding male part of the seal on the part that fits close to this? With clearances of course, because the turbine is rotating but the corresponding part (a stator?) is stationary. Just more guessing by an ordinary grunt. Thanks for these videos AgentJayZ.
Yes, preserving! That is what I was thinking of. As a repair shop do you keep a significant amount of parts preserved/warehoused or does it work better to order as needed for each job?
Detailed & conceptual ...
Exellent vid! Just what we chatted about! So that split blade is repairable? The cooling air holes make the costs involved very aparent! Dose the LM2500 have VIGV's/stators?
@mobius1aic that's an excellent documentary. recommended.
@AgentJayZ Curious as to how the "two piece" turbine blades are held together? Are they bonded some how?
This is one of your best videos yet. Keep it up in 2012!
I calculate the centripetal force on each turbine blade root to be about 231 kN or 50,000 lb. That's incredible. I mean, mind-blowing.
What is your wire brush made of? Do the bristles have to be softer than the metal parts you're cleaning?
Would it be possible to blast nutshells or small glass-balls to clean the surface? They couldn't damage the material but clean and polish it good and fast.
Amazing construction detail on the blades with those tiny air holes. Just out of curiosity, how are they constructed and what is the cost of each pair?
This is a great video!
It's 30 premixers and 75 cups combustor?
What is the fuel it uses?
Cool video! :) thanks... Those forces are unbelievable!! I'm guess that material it's make of is something special?
always wanted to build my own, what accessible materials would you consider being useable for compressor/turbine blades. I'm assuming I can use 316 stainless for compressor blades, but what about turbine, and combustion cans?
@aftp8765 No engines of any kind use titanium turbine blades. The most common mistake I see is people calling the compressor of a turbine engine a "turbine". This is where the confusion about so-called "titanium alloy turbine blades" gets started, I think.
Even the last stages of the compressor in modern engines use steel compressor blades, because the titanium alloy used in the forward stages couldn't survive the heat created by the compression of the air.
Why are there no film cooling holes on the suction side of the nozzles?
Oh and do you have any specific grades of alloy used in the combustion stage in aero engines.
We mainly deal with Haynes Nickel Chromium...
Also for cleaning, do you have something like a Better Engineering Mfg (example) turntable parts washer or does the volume of work not justify the cost of the equipment?
We can change the shape of the holes, for example the cylindrical holes will replaced bye a consoles (converging slot holes) which will increase the cooling effectiveness. I just published a reaserch paper about that. Thank you for your interesting videos.
hamada, i am trying to research who invented the cooling holes, when were they first used, anything you can help with ???
@AgentJayZ You have already corrected some pretty fundamental misunderstandings on my part. So Im ready to be wrong. I just re ran my numbers. So I'll go on record as saying my physics and calcs are correct. My main question is the tip speed of the compressor. Do they run supersonic? If not, that would imply a diameter less than a meter or slower RPM. Or did I convert RPM to time/rev incorrectly.
I really like the shape of the aerofoils on those blades
My aviation experience was limited to radials so your videos have been most interesting. Must be an incredible casting process to make those air-cooled blades.
I am wondering the something. How did they cast that air cooled blades with such small air passages.
y2han Ceramic Cores are used then essentially "melted" out with a chemical process.
bosspackfan4 That's a very tiny hole so the core melted and flow out from that tiny hole?
y2han I visited the GE plant in Evendale, OH where they made the engine. they used finger drills that created the holes, even with the rounding of the blades. It was amazing to watch. My company provided a coating technology that lengthen the life of the LM2500 blade to protect it from the corrosive properties of the high temperatures with the stage1 and stage 2 blades
Did you take a video of the creating holes process?
Amazing how air can heat up and cool down that much just a few inches away
What material are the turbine blade made of?
Do you store any parts with a coat of machine oil/shrink wrap or does that just complicate the cleaning before use?
Awesome
What are the materials that the first state turbine blades are made out of?
Jet turbine engine principles in laymen’s terms. Excellent videos. What keeps the baffle pieces secured between the turbine blades?
They are trapped in place. No where to go.
Ok... I yield to your expertise... I sincerely hope everybody understands that I don't know everything, or even a measurable percentage.... That's one of the things I know for sure!
You are amazing. I wished you if you could make an animated video on this 😔😔
We have two LM2500+G4, on the summer time, on full load, we had compressor discharge air temperature 519 oC (966 F), and pressure 2124 kPa (308.1 psi). On winter time pressure could be about 2600 kPa (377.1 psi).
Is there a how it's made video for these turbine parts.
Happy New Year
I haven't seen a video that describes the path of air to the cooled turbine blades, you have shown the bleed air that cools bearings. Are turbine disks hollow? Or is there a video with the description?
@AgentJayZ i would love to get my hands on this lil beauty... it did make me chuckle when you say the turbine wheels are to large! where i work we are building 3 9fa rotors at the mo.. a turbine wheel off 1 of them is around 4 ton and 6ft OD! we ice blast all the inconel parts and glass bead blast the rest of it! buckets with very small cooling holes like ones you have ther, would go for an xray after we repair them. to make sure ther is no glass bead of shot peen media inside!
greeting joe
i understood High pressure compressor routing to nozzle guide vane through combuster outer ducting....but how does turbine blade get compressor bleed air...whats the routing of air to turbine blade root
Do you know how the cooling holes in the blades are created? Metal casting? Or machined? I'm guessing casting since they aren't straight tubes. Am I right?
Why does running at higher pressure require more seals?
Great to see where those blades go
My job is to grind them dovetail, tips, etc
I bet your nickname is "Mr. Precision" !
Turbine blade roots are the most perfectly finished metal I've ever seen.
@memadmax69 Compressor discharge air in an lm2500 can be over 600F ; we have measured in an LM1500 at 500F
@mobius1aic
yeah i also saw this, it was a really nice docu! Did you see when they made the fan blades with this honeycomb structure in the inside? They kind of blew it up, just amazing technology...
@lazystart We of the parts with oil, but don't wrap them. Everything is kept in a dry but unheated warehouse.
What is the point of lockwire at 2:42?
It goes on the inner side of the tube so couldn't it come off easily?
What size has a first stage turbine blade and what is the weight?
@AgentJayZ dry ice blast with CO2 snow?
Thank you, this video gave me lots of ideas for a compression unit for my plasma turbine engine.
Great videos! One question: Where does the air come from to feed the cooling of the blades?
thanks.
The air is bled into the turbine discs from the thin layer of cooling air between the bypass duct and the core. So once that goes down, the air further exhausts into the jet stream, further lowering the temperature of the very jet stream.
If I'm not mistaken.
Thanks!
3:58 What’s the trick that those tiny holes don’t get clogged over the time?
inlet air filters...?
@AgentJayZ ... preserve some ...
@Scorpion85629 Look up "Rolls-Royce, How To Build A Jumbo Jet Engine", and they have a bit about how THEY build the turbine blades. They are mainly formed via wax molds and the cooling holes are machined afterwards.