How does an Aircraft Engine works in higher altitude without Oxygen?

Answer 1

There is oxygen at higher altitudes. Just not as much as there is at ground level. Jet engines, suck in huge amounts of air, thereby getting enough oxygen to burn with the fuel.

Answer 2

Well if you are talking about a piston type of aircraft engine they can only fly at altitudes where there is enough oxygen in the air to maintain combustion. As the aircraft climbs higher & higher, the performance of the engine will change & be less efficient, so we have a mixture control, so we can adjust the fuel/air ratio, & compensate for the thinner air. That helps at relatively low altitudes, but if the aircraft is intended to fly at even higher altitudes the engine is fitted with a turbocharger, which is like an air compressor, that feeds more concentrated air into the engines air intake.
Now jet engines are another matter because by their design they already have multiple compressor stages built into them, so they are already capable of flying to great altitudes, but still require some amount of oxygen, so they are limited as to how high they can fly.
For an aircraft to be able to fly beyond the Stratosphere it would require a rocket engine. Rocket engines carry their own oxygen supply, so they aren't dependant on an external air source for combustion.

Answer 3

For what it's worth: the limit on altitude is a complex relationship between the decreasing thrust of the engine with altitude, the decreasing speed of sound, the decreasing temperature and the aircraft minimum flying speed.

So at high altitude the plane is near its maximum Mach number (aircraft like 737s and A320s cruise a around M0.8 and max out around M0.85). At 42,000 feet that's about 230kias which isn't far above the minimum 'clean' speed of the aircraft. So if they go much higher their mach limited maximum speed decreases to the point where they can only just hold altitude.

Conversely, at high altitude the engines burn much less fuel and the ground speed is much higher than their indicated air speed. 230kias at 42,000 feet is something near 500kts true air speed.

The incident report below illustrates how close aircraft fly to their limits, the sequence starts with an engine failing to accelerate and results in an uncontrolled descent from 41,000 to 9,500 feet with heavy damage to the airframe.

Answer 4

Small aircraft have air cooled engines because they are lighter and less complex then water cooled engines. There is however a diesel engine that is on the market that does have water cooling. Not sure why it is water cooled other then its makes for better engine temperature control. The most engine cooling required is at low altitudes and high power setting when taking off and climbing to altitude so the cold of high altitudes is not available for cooling.

Answer 5

For the jet enginess that suck in a huge amount of oxygen its not as much of a problem. But even for those high flyers there are altitude limitations. Most commercial jets dont go over 45k feet. while the SR-71 would exceed 100k feet. Little combustion engines like the 172 that I fly usually top out around 13-14k feet.

Answer 6

For piston engine airplane, they use supercharged method or turbo to compress more air to engine. However, above 10k ft even a turbo and supercharged enginer will not be efficent. So, piston engine airplane is designed to fly less than 10k ft.

As far as jet engine, they lose engine power as altitude goes up. But as higher altitude with less air density, the drag will go down as well. Therefore less engine power is needed for crusing at high altitude.

Answer 7

da_royal is correct. For propeller (piston engine) planes, they use superchargers to compress large quantities of air to get enough oxygen to run. Eventually, you assend high enough and the air it too thing for aerodynamics to work (and low on oxygen) for combustion engines like piston and conventional jets. That's where rocket engines take over. They carry both their own fuel and oxydizer to burn and produce thrust.

Answer 8

They are in right, Engines work with the oxigen they find although it is less, in fact the engines performances decrease with altitude.

Answer 9

the fuel that we use is higher octane and therefore, it needs less oxygen to combust at a higher altitude.