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Rolls-Royce are renowned for high quality graphics and illustrations, so it would be nice to see an updated version of this video with Advance / UltraFan technology and improved graphics! Oh, and please remember to include the tail cone in the illustration of the exhaust ... incandescence in the region of the low pressure turbine bearing housing is generally regarded as something to be avoided!
that's. what. we call the true dedication towards. the work.as you did in engineering. hats off for your. dedication. which improves fuel efficiency. in upcoming. engines to decrease. the. level of carbon footprint for the better. future
There is no explosion inside a jet engine. The air entering the combustion chambers is heated. There is no pressure increase in the combustion chamber. The air from the compressor section enters the combustion chamber where the volume increases, by adding a lot of heat, the pressure remains constant. This heated air is allowed to escape through the turbine. the turbine robs some of the energy to drive the compressor. the rest of the air expands rapidly though the jet pipe and you have thrust. I refer to a book written by Rolls Royce, "The Jet Engine" A very good read.
+Sultan Singh The air/fuel mix is ignited by a spark igniter when the engine is starting and then the combustion sustains itself, like a stovetop burner. When the mix is ignited, this accelerates the air back... through the turbines before being ejected through a jet pipe.
What's the break down of the total thrust from: air flow as 'pure thrust' air ignited 'generating more thrust'? You generate most thrust from none combustion?
I am a long time share holder of RR, They have very innovative design and proven technology. Their piston engine division MTU power some of the biggest ships and fastest battle cruisers. MTU also powers high speed ferries using waterjets.
The more systematic use and utilization of electricity and the improvement of equipment and software that allow calculation of ascents and descents with lower fuel consumption, taking into account airflow (stern wind, bow), optimizing B.P.R. The turbofan has to systematically enter the digital area, redirecting the flow of energy produced for greater efficiency, logically in order to reduce consumption. Powerful hardwares, equipped with software would be bringing efficiency data to the cabin. I would propose some corrections that would certainly bring significant results.
Generally all gas turbines depend in their work on drawing air from the outside and then increasing its pressure and speed with condensers to tens of atmospheric pressure depending on the number of disc blades so that the friction between the compressed air particles increases with each other inside the condensers, which raises the temperature of the compressed air to many times the boiling point of water to accelerate the combustion of the fuel spray coming out of the syringes in the combustion chamber, which increases the efficiency and concentration of the directed kinetic energy resulting from the combustion, so that the combustion product acts as a feedback by moving the exhaust blade discs connected to the same axis of the compressor discs to control the work of the turbine, but if the concentrated air pressure inside the condensers is disturbed, the energy of the resultant in the combustion chamber will be dispersed in all directions and may cause an explosion inside the gas turbine, so the margin of error during manufacture of the turbine disc blades does not exceed several microns to ensure the stability of the flow of the compressed air inside the condenser.
Interesting video. Thanks for posting it. Nevertheless, after all the troubles with the Trent 1000 engines in recent years it seems to me Rolls-Royce's repute as "one of the world's leading engineering companies" unfortunately is somewhat at stake. I have no doubts Rolls-Royce once deserved the title "best company in the world" on making engines, but that was back in the days of pistons and fantastic engines such as the Merlin, which I think we all should still be very thankful to Rolls-Royce for. I hope you'll succeed in fixing the problems with your current engines, so that your excellent aim for creating better power for a changing world can be achieved. Best of luck!
CommanderLake Giant passenger jets have huge fans mounted on the front, which work like super-efficient propellers. The fans work in two ways. They slightly increase the air that flows through the center (core) of the engine, producing more thrust with the same fuel (which makes them more efficient). They also blow some of their air around the outside of the main engine, "bypassing" the core completely and producing a backdraft of air like a propeller. In other words, a turbofan produces thrust partly like a turbojet and partly like a turboprop. Low-bypass turbofans send virtually all their air through the core, while high-bypass ones send more air around it. Impressive power and efficiency make turbofans the engines of choice on everything from passenger jets (typically using high-bypass) to jet fighters (low-bypass). The bypass design also cools a jet engine and makes it quieter.
The secret is the narrowing of the air-stream inside the compressor. The compressed air builds to a pressure that is actually higher than that of the fuel/air combustion - but - it has a much smaller cross-sectional area. As the fuel and air combust and move rearward, the passage widens again, but still at a lower pressure than the compressed air-supply (meaning it can never reverse flow). The outlet gases of the engine do more work than the compressor because they have a much larger surface area, so with gearing, the drive turbines are able to compress the air and still have energy left over to propel the aircraft.
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.
We respect US,German , Japanese , French,Italian and other countries engineering..but nothing, Nothing can be better than RR aviation engines. Million out of million engines,never failed. RR aviation, it is a very solid company. Do not make confusion with BMW RR cars.
It's not odd, it's normal, the hot gas gets directed to the Tail Bearing Housing Nozzles, and where the LPT actually is they put the cone to direct airflow back in the center and mix cold and hot gasses on the exterior of the engines
What they left out is that the fan blows air through an ever narrowing bypass duct, this air compresses as it’s forced to squeeze through the ever narrowing duct. Once it gets to the back, it flows around the outside of the combustion chamber and cool it, the bypass heats up and expands, shooting out the back of the bypass nozzle providing jet thrust. That’s how bypass air produces thrust!
0:57 The animation is wrong. The exhaust doesn't exist in the middle as a solid stream but rather from through the annular section at the rear. As you can see at 1:04 there is a metal cone were the exhaust is previously shown to exit, and the annular exhaust nozzle is seen around it.
+MV N Do you mean once the engine is started or how do they spin to start the engine? Once started, energy is absorbed from the combusted gases by the turbine blades and used to spin the compressor and fan blades via a shaft to make the process continuous. In order to start (if I'm not mistaken) I believe aircraft carry a small auxiliary power unit which is used to rotate or spool up the engine until it is running under its own power.
Skipped a few steps there on the turbofan and the exit flame is downright in the wrong place if I understand correctly. I find it's always better to explain how it actually works instead of attempting a simpler incorrect version.
Jet engines scoop air in at speed so, in theory, if you designed the inlet as a rapidly tapering nozzle, you could make it compress the incoming air automatically, without either a compressor or a turbine to power it. Engines that work this way are called ramjets, and since they need the air to be traveling fast, are really suitable only for supersonic and hypersonic (faster-than-sound) planes. Air moving faster than sound as it enters the engine is compressed and slowed down dramatically, to subsonic speeds, mixed with fuel, and ignited by a device called a flame holder, producing a rocket-like exhaust similar to that made by a classic turbojet. Ramjets tend to be used on rocket and missile engines but since they "breathe" air, they cannot be used in space. Scramjets are similar, except that the supersonic air doesn't slow down anything like as much as it speeds through the engine. By remaining supersonic, the air exits at much higher speed, allowing the plane to go considerably faster than one powered by a ramjet (theoretically, up to Mach 15, or 15 times the speed of sound-in the "high hypersonic" region).
Magnets are attractions that have magnetic fields. There are 3 ways to make magnets, namely by rubbing, conducting electricity, and magnetic induction. The use of magnets in specially crafted work that is made using electric current, is widely used in various tools including compasses, electric motors, telephones, and telegraphs.
In the case of commercial jets, the APU (Auxiliary Power Unit), which is usually at the very back of the aircraft, is what's used to start the engines so that the front fan begins rotating and sucks in air to generate thrust. Once the air is ignited with the fuel to produce the hot exhaust gas, a lot of the energy from this exhaust gas is then transferred to the turbine making it rotate. The turbine is connected to the front fan and the compressor by the shaft, allowing them to rotate too, so it becomes a self-sustaining process.