A good overview of how a jet engine works. This specific example is the General Electric GEnx that is used on the Boeing 787. This animation was produced by General Electric.
I have never been able to afford the cars they show in commercials on T.V... But I'll take two of these engines. I have a shopping cart they might fit on.
Haven't work on one in years, but having worked on GE, Pratts, and Rolls Royce/ Allison. Ge was by far made the best. I was impressed that GE made their engineers actually work in rebuild factories before they were allowed to design. They learned to make things easy, murphy proof, and modular. It appears they're finally taking advantage of material innovations and modularity design v. high time components, excellent applications. The next innovation will be extending material life of expensive components like high speed turbines and combustion chambers from breakdown by thermal cycles. Right now they keep the engines running almost constantly, but that can be changed. GE, call me.
This is an overview of the General Electric "GEnx" engine, or the "Next Generation" turbofan; the title is misleading. For people with a basic understanding of turbine engines, this video shows how GE is making improvements. For those that are not familiar with turbine engines, here are the basics: *On the ground, an electric or air powered starter is used to get the engine to start spinning. The engine (front to back) consists of a fan, a compressor, a combustor, a high pressure turbine, and a low pressure turbine. It is called a turbofan because the second turbine spins the fan to generate thrust (move lots of air). *When spinning the compressor pressurizes air and moves it toward the back of the engine. Note that the pressurized air is hot. *Fuel is added and mixed with the hot air in the combustor, where there is also an igniter. The combustion gases expand and accelerate out the combustor and through the turbines. *The high pressure turbine (HPT) is connected to the compressor by a shaft, so spinning the HPT is also spinning the compressor. Note that the compressor, combustor, and first turbine are the engine 'core' - the components responsible for keeping the engine running. *The low pressure turbine (LPT) is connected to the fan by another shaft (here they are counter rotating). So spinning the second turbine is also spinning the fan at the front of the engine. The fan provides most of the thrust. The turbines are on different shafts because the HPT and compressor spin really fast, and the LPT and fan spin slower. The engine powers itself once it is running as long as fuel is being added. The parts are spinning, not reciprocating like a piston in a car engine. The forces in a spinning engine are more constant or 'steady state' and the parts are moving in basically one direction (circle) which is part of what makes turbine engines so reliable. 'Things in motion stay in motion...'
Big thanks to JM on this overview. Cleared some of my previous misunderstanding of the jet engine concept. I think the big fan in front, turns by shafts from HPT and LPT, moves the air towards the back to generate thrust. Might be slow on start but once regulated fuel/explosion comes in, the airflow becomes vastly exponential from repetitive/powerful turbine actions. Correct me if I am wrong.
@@vidjdwhite You have just hit the nail on the head there, sir !! This is NEVER explained but I will now try to explain (but it's only my version that may not be totally correct). Any fan / compressor has what's called a `fan curve' (also pumps have pump curves) to illustrate how it will perform when the flow rate is varied i.e. how the pressure across it will vary as you vary the flow. Invariably as the flow is decreased the pressure across the compressor INCREASES; therefore during start up of the jet engine when the burner is switched on the pressure after the compressor stage increases which will tend to reduce the air flow into the compressor but this reduction in air flow will increase the pressure gain over the compressor so a new BALANCE is achieved with the burner on. Google `fan curve'. With the burner on this vastly increases the volumetric flowrate with the pressure reasonably stable. The same can be said for a locomotive steam engine - with the boiler sitting at e.g. 10 barg (145 psig) and zero steam take off the fire only has to supply boiler heat losses. Once you start to draw steam off the fire has to provide a lot of heat to maintain the steam flow rate at the same pressure.
If a person had no idea how a jet engine worked they would only be a notch better off for watching this video. Its an infomercial for those who are in the industry.
Basically an encased turboprop using light weight alloys, composites, and sensors. Put some automatic directional and output controls on those burners if you want more efficiency.
jet engines are similar to a human eating an xl burrito with lots of chopped up habanero peppers in it. air goes in, its compressed, heat is added for more oomf, propulsion occurs. BOOM
I suspect they are talking about the analysis and optimization performed. In the past computers were not powerful enough to perform a full 3D simulations for these, but now they can get much closer to simulating the entire engine in detail, including air flow. This allows engineers to optimize everything from the shape of the blade to the shape of the cavities around each blade to the way the air flows from blade to blade as well as optimize for strength and weight.
OK, this video convinced me. I'm going to buy GE engines for my entire fleet of passenger jets. At last count, I had... um...35 planes. So.. that's 70 engines, better throw in 20 or 30 more for hot swap spares. Can you send me an invoice?
Mr. PilotTroll: You are right 100%. All light bulb manufactures, more than 80 years ago AGREED to limit the life span of each incandescent bulb to NOT MORE THAN 6 MONTHS. The only incandescent bulbs that last (almost) forever are the ones used by the subways (MTA) in new York City (as far as I know) and those bulbs have the thread counterclockwise, so nobody can use them, unless the socket is available. with counterclockwise thread too. 02/17/18.
Yeah, it's misnamed. It doesn't really explain how jet engines work. A better title would be "How a certain company's new turbofan engines are better than anything that came before." (The name of the company of course, is very hard to detect from the video -- you have to look and listen very closely.)
The air has lesser space each paddle, and because of the high speed it cant go back but gets pushed forward. Than the paddle hits it and twist it -> than that mixes and burns, and all that tries to go out, in an even narrower hole, which pushes the plane forward.
PixelCortex AFAIK, schematically: compressor, combustion chambers, turbine. A jet engine takes a certain amount of incoming air in the unit of time (the flow rate is a volume in the unit of time, like m3/sec ...) and then accelerates it to the exhaust. The greater is the accelerated flow into the engine, the greater will be the thrust. The combustion chambers accelerate the airflow like an explosion (air and fuel). For amplify all this, the output flow of the combustion chambers hits the blades of a turbine. This turbine spins a compressor put in the front of the engine. The compressor further compresses the incoming airflow for the combustion chambers, further amplifying the incoming flow rate, so amplifying the thrust. Modern turbofans have also a fan keyed on the shaft of the turbine, like a propeller. This fan is run by the turbine. The fan works in the lower atmosphere (take off and climb), where the air is more dense, like a very efficient propeller; while the jet works better in the higher atmosphere. This combination increases the efficiency of the engine and decreases fuel consumption.
Normally the exhaust air is straightened by the turbine exit vanes which have an angle (see the the engine from behind in the video). The oppsite rotating compressors are made to counteract the gyroscopic effect and therefore also give a better fuel economy.
LOL!! Really? Assuming this wasn't just a joke....OK, look at the video again. at 0:55. See that the Fan ('N1') and the LPC (Low Pressure compressor) are attached to the same shaft? Then, farther back in the engine (at 1:55) is the LPT (Low pressure Turbine). These components are connected together front to back, and rotate together. The center components (HPC and HPT), where the higher compression takes place, and the hottest and most pressure of combustion, these are turning together, on concentric shafts. BTW, the engine is started by turning the "center" part (the 'N2'), and this has been done traditionally by compressed air (although the Boeing 787 uses an electric starter). As the N2 section begins to turn, the airflow it produces then causes N1 to turn...and the Fan of course.
767Captain I still don't understand, are you saying the starter spins the main? shaft which spins the fans to pressurize the air and then that pressure keeps it going?
RCcrAzY1234 To start the process, an electric motor (starter) spins the blades, so the compressor starts to compress the air into the combustion chamber (compressed air is hot) where you add fuel. The mix ignites and the propulsion spins the turbine blades while exiting. Because turbine blades are conected to the compressor blades by a shaft, the propulsion turning the turbine is now turing the compressor as well. At that stage the electric motor is turned of and the jet engine is turning on its own. note: the compressore blades are in the front, turbine is in the back. But all are on the same shaft. The propulsion that spins the blades is pushing the engine forward when it exits in the back so it has two jobs, turning the engine and pushing the plane forward. Hope it helped.
The spin is to inhale anyone who ignore's the danger. I was in an Intruder squadron with the P&W J-52-P8A/B. There is a fascinating video here that shows a Navy crewman getting too close. He was very lucky.
TheDustysix A reciprocating engine uses mechanical energy that goes up and down and converts it to a rotating shaft. A turbine is already spinning, therefore no silly up and down. The whole jet engine theory, in the US, was when one looked at the schematics for the Lockheed P-38 and the Republic P-47, with there superchargers, turbochargers and intercoolers. The reciprocating engine merely got in the way. It is not necessary. In aviation, it gets tossed.
Maxime Guillaume. filed his patent for the turbojet aircraft engine (no. 534,801) on 3 May 1921 and was granted 13 January 1922 The first turbojet engine was built by Hans von Ohain in 1934 and the first sucessful test flight of a jet propelled aircraft was August 27, 1939 by the HeS 3 engine designed by von Ohain
Correction. General Electric is the leading manufacturer of aircraft engines ( Rolls-Royce is second ) and dwarfs RR in every other way. GE also holds the record for world's most powerful commercial engine ( GE90-115B ), and the B747 utilizes engines not only from RR, but also Pratt & Whitney and GE, including the latest GEnx.
The reasons you give make sense to me. I think there is one more key factor, the initial input of energy from the starter engine gets the air-flow going in the right direction which creates the steep pressure difference between the air coming from the compressor & the air escaping via the turbine. What do you think?
Excellent promotional video. However, it would be much better if the narrator spoke in normal conversational English rather than with the breathless tone s of awe and excitation that are frankly ridiculous.
very good explanation. its easy to understand. I would like to know does it required any external power to rotate the fans in the initial stage. how it starts spin in the initial stage.
Excellent presentation. But, what really gets me is despite the impressive academic view of things, I am totally amazed at how air is compressed to the degree at which it is and how it operates by the time this squeezed gas reaches the ignition chamber. Would love to see this happen in real time in order to better appreciate the engineering genius behind such devices and how these engines push so many tons through the air for, as I experienced twice in my life, 14 hours of confident flight.
Yup, you got that right. A guy in airplane equipped with Rolls Royce engine pulls up to another airplane that is also equipped with Rolls Royce engine and said to him, " Excuse me, wouldn't you have a grey poupon?"
Older model jet engines relied heavily on exhaust propulsion system (waste of fuel energy) instead an ergonomic design of higher bypass fan blade ratio, smooth lines, exhaust gasses elliptic motion and preferably cryogenic air cooling system. Definitely the lesser in number slower moving wider 3D S shaped fan blades is the ultimate in efficiency. Added with a silence system necessary to the majority of large jet engines. Excellent achievement enhanced by the new age materials and manufacturing techniques. Definitely a safer, eco friendly, reliable, economic, and quieter way to fly.
@@vasiliostheodorou4849 Yep I agree. I even left my humble opinion "upstairs" before I read yours. It's the design of composite materials combined with large fan blades that simulate a propeller that has a special "three gear gizmo" that allows the energy to be safely transferred from the jet portion to the fanjet portion. The guy who designed the "transmission" should receive a Nobel prize, IMHO
Yes, but it's a sales pitch that is intended to be shown to Engineers who will be using this engine in their product. Engineers are all about how does it work and how it is better than other methods. Thus if you read the description it states what this is. Yes it's a sales pitch, but it is a very good overview of the design and inner workings of a jet engine.
This advertiser is simply using advanced graphics and stilted language to distract you from the primary take away message: The environmental extremists comprising the all powerful EPA have overhauled the global emission regulations and standards to the extent that all power plant manufacturers have to design entirely new engines to comply with regulations created with the intent of punishing the participants of internal combustion technology. The advertised product is simply what GE had to do in order to survive as a player in manufacturers of gas turbines in the EPA's "brave new green/clean world." The alternative would have been to spin off that segment of it's operations. Accordingly, this well-pitched turbine powerplant will cost many orders of magnitude more to acquire and maintain than any of it's predecessors just five years ago. Wouldn't it be nice if this were the end of the story, but it's only the beginning. The EPA took special care to ensure that internally-combusted power come at a much steeper price, and that's only step one. Just a fashion of similar fanaticism, our friends at EPA made sure that not only would new petro-chemical powerplants be uber expensive, but that they would also lag far behind the performance parameters we have become accustomed to as a society for sixty years running. Put a tad more succinctly, the EPA has launched a full-frontal assault on everything that used to be "sexy" about gas-burning engines. If fast, loud, and powerful are adjectives that hold positive connote with you, then you're in for a big disappointment. The elite intellectuals of the EPA are going to see to it that you, me, and we are all going to "enjoy" jet powered aviation at a much higher cost, with a performance suite that is the rock bottom minimum necessary thrust component to keep us in the air. Sexy IS ain't what sexy WAS. Forty years ago, a typical non-stop 600 mile fliJht was comprised of a 727 which was really fast, really loud, and kicked out a little black exhaust trail behind her. If you went wheels up out of GSP, you'd be touching down in PHL in only slightly more than an hour. Today, hat same non-stop flight takes nearly two hours. Progress? I think not. Flying today is akin to animal husbandry. No longer considered to be urbane, or adventurous, it's torturous. We don't make out way to the gate, but rather, we are hearded there. We don't check in anymore, we're "processed," like so many head of cattle. And that big 'ole jet airplane....that Steve Miller sang of in 1974 has been supplanted by fleets of puny, new, slow (barely) jet airplanes. Here's a tip for you frequent flyers spending hundreds of hours vacuum packed in regional jets: there are more than a few single-engine turbo prop air craft in the general aviation/civil aviation world that regularly cruise at speeds considerably higher than the 350 knots cruising speed you'll max out at during your 1-3 hour flight in your CRJ. That's not to say that your CRJ can't outrun the GA turbo-prop, it's just not ALLOWED to, thanks to ATC and the FAA. It's all about traffic management and keeping them separated up there. The only chance you'll get to experience airspeeds of 500+ knots in a regional jet these days is if you're on a non-stopper with a 400+ mile distance spread b/t departure and destination (and if your flight plan takes you over lesser-congested air routes (vis a vis: out west). We are unwilling converts into the cult of man-caused climate change. It was fun while it lasted.
This engine,due to its modular structure is very easy to upgrade, modify and tune to its specific requirements like speed,range,power and most probably,the arrival of new upgraded parts with new features to enhance its capabilities with less time taken to upgrade it.
lol. rolls royce. Their engines are terrible. GE or pratt and whitney arw far superior. Besides rolls royce are predicted to go out of business ince chinese perfect manufacturing as their engines are of such poor comparitive quality
suck squeeze bang blow. what makes you think Rolls Royce is better ? can you give us some time on wing or cycles between overhaul . what are you basing it on ? we have some pretty smart people HERE in US. and it is how one works(simplified for the public)
You have just hit the nail on the head there, sir !! This is NEVER explained but I will now try to explain (but it's only my version that may not be totally correct). Any fan / compressor has what's called a `fan curve' (also pumps have pump curves) to illustrate how it will perform when the flow rate is varied i.e. how the pressure across it will vary as you vary the flow. Invariably as the flow is decreased the pressure across the compressor INCREASES; therefore during start up of the jet engine when the burner is switched on the pressure after the compressor stage increases which will tend to reduce the air flow into the compressor but this reduction in air flow will increase the pressure gain over the compressor so a new BALANCE is achieved with the burner on. Google `fan curve'. With the burner on this vastly increases the volumetric flowrate with the pressure reasonably stable. The same can be said for a locomotive steam engine - with the boiler sitting at e.g. 10 barg (145 psig) and zero steam take off the fire only has to supply boiler heat losses. Once you start to draw steam off the fire has to provide a lot of heat to maintain the steam flow rate at the same pressure.
Ill explain: the combustion chamber (the part where they talked about the swirlers in this video) consists of a combustion chamber (the housing) and a flametube that has a series of holes in it Ill explain a simple version: There are three main types of holes: Primary: combustion Secondary: burns off remaining mix Tertiary: cools the combustion gasses The total hole area equates to the total intake area of the engine, so the holes match the airflow The primary holes are alot of small holes and they have an airspeed that is low enough to let a flame burn, the air just enters in alot of places. The secondary holes let remaining mix burn off, and there are usually less holes and not as much area as the primary. Now tertiary has the bigges hole area (like 50%) and has big holes that penetrate deep into the flametube to cool of the gases before they enter the turbind, so that the turbine doesnt melt. I hope that kind of explains it Edit: sometimes, air vortexes are used to "anchor" the flame so the combustion chamber can be smaller and the flame cant go anywhere
I agree- sure - the video is mislabled but it still shows what the engine looks like "under the hood". I guess those angry with the "advertising" - would be a lot happier if the video started with saying "suck, squeeze burn and blow". LOL. It is amazing - I have been flying for 22 years - which is nearly 1/5 the entire time man knew how to fly. From kitty hawk to now - amazing how much the earth changed
I don't think he's talking about the compression system rotating against the intake fan, but rather the counter rotating fan system utilized to stabilize the exhaust flow for optimized static pressure.
My challenge to the commercial airline engine manufacturers is this: to create a very powerful jet turbine engine which can easily and SAFELY break right through the sound barrier with as low friction and shaking as possible. Once this can be achieved Mach 1 or 2 and perhaps 3 could dramatically reduce travel time globally(internationally). The problem may then be the massive heat produced by the engine at speeds above Mach 1 or greater. Can the engine be cooled within the casing thus preventing overheating? How much bigger would the turbine need to be including the casing? Velocities which can top the speed of 1 time zone per hour would be great and closing in on 2 time zones per hour would be astoundingly amazing. Crossing the Atlantic Ocean bound for Europe in 2 hours from NYC or WDC to London or Paris would be quite an aviation feat. Indeed. SF or LAX to Tokyo in 5 or 6 hours would be fantastic.
Why are the stators static and not rotating in the opposite direction. Wouldn't that help provide more compression faster? Like 10 compressor blades+ 10 static stators maybe equal to 5 compressor blades + 5 moving stator blades? Like the blades on a KA 52 helicopter .
reducing fan blade speed when you are in flight, or when you are landing the outer wing will open and makes the break-like cars, except it use aero's force instead of break disc. sit near middle seat (near the wings) when you have a flight and see how this works, its pretty sexy to see how the wing works lol
the material used in building the internal parts save on the environment too, not just in fuel consumption but also the parts, and metal refineries will run less often to construct replacement parts as less part replacement, less need to construct for given aircraft. thus less environmental hazards resulting in manufacturing and labor.
I think I understand. Basically the whirling air coming off the first set of turbine stages would be spinning in the same direction as the second set and therefore wouldn't produce much work because it would just "slip through". Is that more or less what you mean?
I was in a bar many years ago and an American Airlines Mechanic who had a fews drinks was asked about thier maintenance program - he said our corporate motto at American is "If it can fly in, it can fly out"
I wouldn't even compare a turbofan engine with an answering machine. Generally, an answering machine isn't responsible for possibly hundreds of lives in a virtual tin can. GE Aeroengines are pretty damn good engines.
yes. both have the same principle in burning but differs the propulsion. a turbojet, the propulsion is by its exhaust while in a turbofan, the propulsion is by a fan.
I would like to know does it required any external power to rotate the fans in the initial stage. how it starts spin in the initial stage.it will be greatful if you replay
How does the counter-rotating turbine improve efficiency? 1. By reducing number of stationary airflow directing parts ( vanes ) and corresponding drag and energy loss. 2. decreasing weight and 3. decreasing turbine length. There are papers on the subject but links are not allowed here for some reason. Google is your friend.
So is the air flowing through the fan providing most of the propulsion or is most of the propulsion (thrust) coming from air flowing through the core? I think that's what most laymen don't understand, and need clarified. :)
I was thinking that the spiral flow off of the main turbine was causing the second to not be as efficient as it wouldn't produce as much pressure against the turbine blades, but are you saying that the only increase in efficiency is the propulsive thrust generated as it leaves the engine? It makes sense now that I think about it. Could it be a combination of the two that adds efficiency?
