What is bleed air? Can someone explain in simple terms. No links to other websites pls just in your words.
2007-08-24 01:53:53 · 2 answers · asked by Anonymous in Cars & Transportation ➔ Aircraft
Bleed air is compressed air taken “away” from the compressor of a gas turbine engine. ( before it is mixed with fuel in the combustion chamber)
This is collected by an inlet or duct and channeled by pipes to cooling units, accessories etc.
This warm and compressed air is used for different purposes on an aircraft. It can be used to pressurize the cabin, to use for deice and to power pneumatic pistons or actuators. ( I say warm because even after exiting the compressor stage the air can be quite hot, up to 200 C on some engines)
To cool the air for cabin pressurization it is passed through air-conditioning packs. ( Although they are technically heat exchangers)
For de icing it is directed to crucial parts of the wing and empennage and vented through tubes. This warms everything up. Some aircraft (737 NG comes to mind) have small dime sized holes that allow the warm air to flow downward and “dump” overboard. This helps prevent ice from forming in the slat’s gap.
Another use of bleed air is to start the engine. In this case, bleed air is supplied from the APU and is redirected to the engine. The air spins the compressor and turbine, fuel is injected and a spark added, and you have ignition.
There are many more uses of bleed air on aircraft. I’ll let others add some.
2007-08-24 02:02:11 · answer #1 · answered by Charles 5 · 9⤊ 1⤋
WOW ! Total complete idiots DO exist ! And they are among us in yahoo answers ! First of all , you have to actually KNOW something about how modern large jet systems work before you start making claims. A lot of the air used to pressurize the cabin comes from outside , not the engines. The engine bleed air is used to turn the turbine powering the compressor and to modify the temperature of the compressed air using what we call a "trim air valve". That engine air is taken from the compressor section, well before the burner area. so its just compressed outside air. The smells you get in the cabin almost always happen on the ground when the engines suck in the exhaust fumes from other aircraft or even ground equipment. Now to the 787. It does not use bleed air to drive the compressor turbine , It will use an electric motor to drive the turbine. So now an even HIGHER percentage of the cabin air will come direct from outside the plane . Including all those fumes and odors from other aircraft , ground equip etc. AH YES ! problem NOT solved after all , is it !
2016-03-19 01:05:45 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Air Bleed
2016-12-29 04:03:14 · answer #3 · answered by ? 4 · 0⤊ 0⤋
Bleed air is air which is bled off (like bleeding a radiator to get the air out) from the compressor section of a gas turbine engine.
This high pressure air can then be used for pressurization and wherever an air powered motor is required. You can cross feed the bleed air to start another engine or you can use it to pressurize the plane.
(Do turbocharged piston aircraft use turbocharger air for pressurization?)
You can not use it for de-icing because it would be at the same temperature, if not lower, than the rest of the air.
Some aircraft use bleed air to enhance the effectiveness of control surfaces at low speed.
2007-08-24 05:45:21 · answer #4 · answered by Chris H 6 · 0⤊ 1⤋
Bleed air is compressed air from a jet engine which is "bled" off from the engine to power systems on an airliner. The 787 will be the first airliner in service that does not use this. Compressors run by electricity suppied by the engines will take it's place. This is thought to result in increased efficiency of the engines.
2007-08-24 16:55:43 · answer #5 · answered by ericbryce2 7 · 0⤊ 0⤋
Bleed air is the air which is 'syphoned off' from the turbine engines after the compression stage and before entering the section where fuel is mixed and ignition takes place.
It is a purpose built facility with multiple uses throughout the aircraft.
2007-08-24 04:43:18 · answer #6 · answered by al_sheda 4 · 1⤊ 1⤋
Charles M has it exactly right. Chris H is wrong, that the air is too cool for de-ice purposes. Maybe on bug-smashers, but not on transport aircraft.
2007-08-24 07:30:22 · answer #7 · answered by RGTIII 5 · 0⤊ 1⤋
We used an experimental APU on one airplane to pressurize an air manifold that could be used for in the field maintenance(for use of air powered tools). Only one of these APU's was built as far as I know. We used it for one deployment to the middle east. The design was poor and to much air was drawn from the engine which overheated the APU at times. Its not a common use answer, I know, but it was one no one had said.
2007-08-24 04:12:15 · answer #8 · answered by Anonymous · 0⤊ 3⤋
Sorry Chuck. That ain't even close. Maybe in a submarine, I wouldn't know, but not in an airplane.
2007-08-24 02:22:42 · answer #9 · answered by Anonymous · 2⤊ 0⤋
It is air bled from the compressor section of the engine.
2007-08-24 17:28:16 · answer #10 · answered by phillipk_1959 6 · 0⤊ 1⤋