Jet Questions 56

LM2500 annular combustor liner
In flight fluid leaks on airliner engines
Types of stators and their function
Centrifugal air-oil separator

[Jangle]

Alright...the tour through the LM 2500 combustor liner was splendid.  I have to admit that there is breathtaking objective beauty behind the design function.  The market value of the liner is astonishing to learn about.  Because the cost of the fuel nozzles are $15-20k each, times thirty nozzles, the cost of entire combustor liner and plumbing must be well north of $1M.

[classekaka]

Thanks! The whiteboard chart with arrows really gave me an epiphany. I've allays pictured the air to go more or less straight front to back without much of a "rotation".

[Daluke]

I've seen a few videos describing  the operation of annular combustors in fairly general terms; this one's more specific and definitely helped me fill in some blanks.

[kosta]

It took a while, but I've finally caught up with this awesome video series!

[dennypollard]

AgentJayZ, yes I would like to see the individual video clips on engine airflow as this subject it is so miss understood as is airflow pressure. The aviation school I test on behalf of the FAA used many of your videos for instructional purposes on turbine engines. Great stuff.

[scarecrow]

let's run a comb through that hair.... lmao... beautiful. the commentary is just as valuable as the visual content. thank you again Jay. u rock.

[compactc]

Interestingly there's something much like the air-oil separator in the world of vacuum cleaners. Some vacuum cleaners use water as a filter rather than a bag or paper filter or a cyclonic setup. They work by violently bubbling the air through the water, but then the water has to be separated from the air before it can leave the filtration chamber, most water filter vacuums will have a separator on the intake of the motor, its a cup with a bunch of slots in it basically, and its attached to the motor's shaft and spins at the same speed as the motor and fans, and uses the same exact principle that the air-oil separator uses here. I think its fascinating.

[lmelin]

amazing they can make those combusters so precisely that they don't distort like pretzels from all the temerature changes and differentials they encounter

[chaos]

OMG that new mic, thank you so so much huge improvement.

[slamdvw]

On my screen, in the list of videos, is "Compressors - Turbine Engines, A closer look"  When you were describing the purpose / design / shape of the blades and stators, you could see their shape in the snapshot of that video.

[ing.rodolfoastrada]

Hi Jay! thanks for the detailed walk around / inside the LM2500 annular combustor liner and rationalization about what otherwise may seem an outrageously expensive piece.
Certainly tight tolerances and lots of highly skilled man hours involved go a long way towards an explanation.
Checking an excelent book by Rolls Royce (tesla - ebook The Jet Engine Gas Turbine, Turbojet, Turbofan Rolls-Royce) I did not see as much detail as your presentation - like the critical issue (with regards to reliability) of achieving pheripheraly uniform liner outlet gas flow to minimize periodic thermal stress on first stage turbine blades and so forth.
As an engineer I can tell you do a great job honestly working around more theoretical issues yet pointing in the right direction.

[poppopscarvinshop]

There's a Fortune in Forming Dies for that thing! Not to mention how long it takes to manufacture....

[alancaraway]

Jay, received my book on Monday, thanks for the info about it. Proves to be very technical. I like technical!

[michaelmooney]

so the blades accelerate the air and the stators convert motion into pressure?
in my early days in the early 90's I miss-adjusted the stators on a UH1H engine and experienced the joy that is a compressor stall.

[KarriKoivusalo]

I would've thought the oil mist separator was just a fancy cyclonic separator, but damn..

[almfreak]

New mic sounds pretty good!  It tames the "echo chamber" quite nicely.

[nj]

Mr Z,
With the recent advances in 3D printing, the annular combustor liner looks like it would be a perfect candidate!!! I saw where NASA had used a 3D printer to print a scaled down rocket nozzle... Will wonders never cease ??? Thanks for the Vids :-)

[Jangle]

Just re-watched Q56  and the video "Compressors...A closer Look" to help solidify my understanding of the the stator's function is to form a divergent pathway so as to increase pressure within the compression stages, is it correct that the shape of each individual stator blade is wedge shaped along the camber line with the leading edge the thickest portion and the trailing edge the thinnest portion?  I can't imagine any other way to form a divergent pathway through the stators, although it is hard to see any wedge-shape in the stators in your videos.

[nixie]

"Turbine neds to experience the same amount temperature and force as it travels in a circle"
That brought to my mind and turbine design I saw long ago, made for a car, where the same turbine disk was used half to compress air, and half to drive itself. I can't find any schematics, but it seems to me that that would have been at the very least, an inefficient engine. Ever heard of it?

[youtubasoarus]

Getting fancy with the remote mic setup. That stuff ain't cheap. Kudos for the extra effort. :)