How does a jet engine work at high altitude?

Jet engines work more efficiently at high altitude because the air is cooler. Hence, the larger the expansion of the air when heated, the faster the aircraft moves because it is the expansion of air that drives the turbines of the jet engine which generates more power for lesser fuel burn.

Do jet engines need air?

As featured on NASA’s Destination Tomorrow. Jet engines move the airplane forward with a great force that is produced by a tremendous thrust and causes the plane to fly very fast. All jet engines, which are also called gas turbines, work on the same principle. The engine sucks air in at the front with a fan.

Why do jet engines need air?

The mixture of air and fuel catches fire. This provides a high temperature, high-energy airflow. The fuel burns with the oxygen in the compressed air, producing hot expanding gases. Turbine – The high-energy airflow coming out of the combustor goes into the turbine, causing the turbine blades to rotate.

How altitude affects engine performance?

Higher Altitude Means Less Power Reduced oxygen in high altitudes can lead to inefficient, sluggish engine performance because there is less air to feed the internal combustion engine. Generally speaking, an engine loses three percent of its rated power for every 1,000 feet of altitude gained.

What happens to gas at high altitude?

Gases at sea level are also compressed by the weight of the atmosphere above them. At higher altitudes the atmospheric pressure is lower and the air is less dense than at higher altitudes. If your ears have ever “popped,” you have experienced a change in air pressure.

How does altitude affect thrust?

Factors Affecting Thrust – Altitude: With an increase in altitude, however, the rate of thrust decreases because a pressure drop is greater than the thrust increase resulting from a temperature drop. This means an engine will produce less thrust as it increases in altitude.

How does thrust vary with altitude?

Thrust lapse Naturally, net thrust will decrease with altitude, because of the lower air density. There is also, however, a flight speed effect. Initially as the aircraft gains speed down the runway, there will be little increase in nozzle pressure and temperature, because the ram rise in the intake is very small.

How does altitude affect the efficiency of a jet engine?

Generally, the cooler and less dense air at high altitude the less the fuel to air mixture in the combustor, thereby improving fuel efficiency. In addition, flying at a high altitude provides thermal efficiency for the engine. The thermal efficiency cycle of a jet engine is determined by the temperatures of the incoming air and the outgoing air.

How do planes fly at such high altitudes?

The air gets fed into the cylinders directly for combustion, and as the air becomes thinner as you go higher and higher, the engine loses its ability to create much needed power. However, there are turbocharged piston engine aircraft that are able to cruise at very high altitudes (25 to even 34,000 ft).

Why do jet engines take off so fast?

When a pilot takes off in a jet engine aircraft, the engine takes air from the front intake. As the plane climbs to a higher altitude, the air becomes less dense (that is, there is less mass of air per volume). Therefore, the pilot needs to move faster so that the mass of the air coming through the intake per second remains constant.

Why do jet engines use less fuel when the pressure is low?

The net result is less fuel needed to produce the same pressure differential when the air outside has a lower pressure, e.g. cruise flight. Some of the other answers/comments make reference to mass flow through the jet, and particularly the mass flow through the exhaust nozzle.