The hot parts of an Orenda 14 turbojet engine for a Sabre jet fighter from the Korean war era. Inspecting the turbine inlet guide vanes for heat damage, including acceptance standards for cracks.
"I know that's not exciting." Wait ... watching an expert ... seeing an actual rebuild manual ... close-ups of real components from a classic engine. You're right it's not exciting it's FASCINATING! THANK YOU!
The funny thing Is, even from department to department here at Pratt, they call the turbine stator something different. I call them" the turbine stator " engineering calls them "the turbine guide vane " management will just call them " vanes " inspectors call them by their part number. It gets confusing super quickly
I was a crewman on a US Abrams tank back in my army days and the turbine engine had something called a recuperator. I have no idea what it does or where it is. I wasn’t a mechanic, I just rode them.
The recuperator is a heat exchanger that scavenges waste heat from the exhaust (after the power turbine) and puts that recovered heat back into the compressed intake air, that is the air going from the compressor to the combustor. Its purpose is to improve the fuel efficiency.
The F-86 Sabre really was one of the best planes ever, according to no less a pilot than Capt Eric "Winkle" Brown RN, and he really did know what he was talking about.
A truly great man. Nobody will ever beat his record. He flew the BV-141, which I built a model of as a teenager. Everybody thought I built it wrong, but they were wrong. Oh, to take one of those to Oshkosh!
@@AgentJayZ Agreed! I had the privilege of meeting him a couple of years before he died, when a gave a lecture at the Fleet Air Arm Museum at Yeovilton. He was introduced to the audience with the news that he'd just bought himself a new sports car. I am convinced that, as a small boy, I saw a BV-141 being test flown a couple of years after the war. It was a warm sunny summer's day and I heard an unusual engine noise above me. I looked up and saw this odd-shaped aeroplane, which I would now describe as asymmetric. Years later, looking through a book on German WWII aircraft, I came upon a photo of the plane that I had seen.
"Boeing is not cause for rejection", did a spit take with my coffee there :-) Ah, bowing... I wonder how many 1000s of hours of test running are behind those instructions. For every sentence in that manual someone has to have inspected a part, seen some damage and then ran it for another 400 hours without it causing a problem. For how many years had the engine been operational when that manual was last updated? Have you compared different manuals to find out what has changed over a few years of service? Some criteria tightened? Some criteria loosened?
Your videos are the best ways to attract potential customers - the best advertisements I have ever seen. BTW, is that possible welding the crack (under argon) before ceramic coating?
No cracks are acceptable on turbine blades, so no repairs. On the turbine inlet stators, or guide vanes, also known as nozzles, there are allowances for cracks, but there is no acceptable repair scheme. The cracks get to the point where they exceed the allowable limit, making the part unusable, and then it is garbage.
NICE SHIRT!!!! Hope all is well Jay. At P&W, we worry about erosion more than anything, one thing modern turbofan engines cannot do without is rhodium (element) in its hot section ceramic coatings. It is very expensive so we have tried but the vanes erode, fast. Another thing that helps acceptance is if you have a LPT or not.
The CF6-6 and early Lm2500 used Stg1 and 2 turbine blades that were mated together to make a single blade. The shop in Evendale where I worked was called the bucket shop
Upon further poking around the HP and LP seal leakage air that has already been pressurized once is harvested and reintroduced as cooling air for maximum efficiency. That way you don't have to steal more bleed air if you already have a source of (relatively) cooler air that has already been compressed. Hence the name 'recoup'
I would had really liked to had seen the Iroquois developed into a production engine. It and the Avro Arrow interceptor for which it was designed were the first use of titanium as a major component in aerospace construction.
Laymen here. What causes the cracks on the nozzles? It looks like the crack has significant width, but I assume the material isn’t missing. Are the nozzles under extreme tension, or is the metal “bunched up” on either side from some metal grain change?
Every start, taxi, takeoff, cruise, landing, taxi, and shutdown comprises what is called a heat cycle. The nozzles experience temperatures ranging from ambient to 1400F or more, a sustained period of operation at around 1200F, and then a rapid cooldown from about 800F. Thermal expansion and contraction eventually causes metal under such conditions to crack.
Jay, since the books and manufacturing of these engines are 50 odd years old, do the manufacturer's ever update the old books and procedures? As time and technology progress do they ever find something in the books maybe unsafe by today's standards or maybe hazardous so a change needs to happen? Just wondering
Apologies if this has been asked in ANY prior video comment section, Do you ever have to x-ray parts to judge hidden/metallurgical robustness in a donated part? Or can be done using available external inspection or testing with shop tools (say like judging hardness of a heat-treated part, things like that).
@@AgentJayZ Looking forward to it! Blancolirio introduced me to your site. Very interesting stuff! I am a recreational flight instructor at uFly Simulator in Mississauga. Sometimes the news stations call us to explain and demonstrate in the simulator what happened and why. Tough couple of years for the 737.
I noticed the small bottles of tire sealant on the shelf. Some aircraft have self sealing tanks. Are there any applications for self sealing /healing features inside a gas turbine engine? I know you've mentioned an edge seal to prevent gas escape that actually wears into place, carbon of some sort I think.
Those are bottles of tire sealant for my mountain bike. There are no self-healing features inside turbine engines. Not the ones I've worked on anyway. The turbine tip seals sometimes come into slight contact with shrouds that are built up of an abradable material, allowing the tips of the turbine blades to "wear in" their own pathway, and this makes a fairly good seal against gases leaking around the tip. Design features like this are being incorporated more and more into modern engines, in an effort to increase overall efficiency.
CTX 1300 is an intercity comfort missile. I employ it as a long distance tourer. I does a pretty good job, but no cruise control. Massive torque though!
Do you also weigh all those parts when putting them together to make sure the ensamble is balanced down to the microgram, or are they already so?! OR, since they do not spin anyway, it doesn't really matter?
How many hours on average does it take to fully service an engine that large, or is it something which varies too much to say based on what’s needed service-wise, and which engine it is?
Can you please explain me about the requirement of Bleed Valves in axial flow Compressors to avoid rotating stall? Probably, it's an old design. If possible, you can suggest me some literature to refer, online! Have been trying to find it out for last few months but couldn't get proper literature!
Sir i like your videos. U make videos of the old engines. I am an AME student. Can u suggest me a RU-vid channel who makes videos on the modern engines.
What I really meant was, the basic principles of how jet engines work has not changed since the very first ones. Any actual specific procedure needed for any specific engine will be in the engine overhaul manual for that engine. Any reasonable AME student should and would know that. So, completely missing the point of my videos... all of them.
I have a playlist called Your Questions. Somewhere in that playlist is a video called "Books!" Also, if you search the internet for "jet engine" you will find something really good published by RR.
1. how do stator vanes turn fast air into slow higher pressure air? Is it analogous to a water hammer? 2. what's the typical angle of inlet guide vanes?
1 Its a process called aerodynamic diffusion. 2 every engine is different. Modern engines have variable inlet guide vanes. The angle varies with air speed, density, and engine speed.
Yes. The rotating blades on the spinning rotor increase the velocity of the air. The divergent pathway between the stator vanes causes the air to slow down and increase in pressure.
