Jet engine how does it work

Pilots must have a strong understanding of every aspect of an airplane to ensure a safe and efficient flight. This guide explores the question: how do jet engines work? For those born into the jet age , it is easy to take this technology for granted. Even when on a jet, long journeys such as from Florida to Hawaii can still take hours, but imagine undertaking the flight without the powerful speeds jet engines can provide.

Pilots who fly jets require a type rating and other certifications which are beyond the private certificate , and those who are authorized to act as pilot in command PIC dedicate study time to learning about how jet engines work.

Having a strong grasp of this enables pilots to aviate safely, more efficiently, and with a greater understanding of how the engine is working with aerodynamic forces to land, cruise, and take off again. To fully appreciate the importance of the jet engine and its place in aviation, it is best to know how they came to be and what they have for the most part replaced.

Early aviation dreamers sketched prototypes of jet engines before even balloons and gliders became possible. Before jets, airplanes were and many still are powered by piston engine, propeller-driven engines.

While the development of turboprop engines helped to increase the speed, thrust, and power of airplanes, aeronautical engineers still struggled to harness jet power.

As with most aircraft innovation, jet engine innovation was propelled by war. A handful of the first aviation pioneers, among them Samuel Langley, were funded by the U.

War Department to achieve powered human flight so that it could be deployed as a weapon. Although the first Wright Brothers flight took place only a few years before the outbreak of World War I, aviation technology quickly advanced during the war to the point where airplane-to-airplane dogfighting took place in open cockpit aircraft. World War II prompted scientists and engineers racing to develop not only rocket and missile technology, but also jet engines.

As early as , jet engines were in existence but mostly in laboratories. German physicist Hans van Ohain developed a workable jet engine which could be used in a fighter.

The airplane itself was constructed by Messerschmitt and called the Me Like all jets, the airplane consumed an enormous amount of fuel, and engineers struggled with this early version as it was difficult to keep it in the air when consumables were in high demand.

It did not fly much, but it was a strong first step. At the same time, British innovator Frank Whittle developed his own jet engine, which was used in the Gloster Meteor. It was occasionally deployed as a defensive measure, but its relative lack of speed made it impractical for overseas combat. After the war, the application of jet engines turned to passenger airlines. Once this was achievable, jet travel became much cheaper and more accessible.

The jet age is generally accepted as beginning in , when the now-defunct Pan American Airlines began overseas jet service on Boeing s. At the front of a jet engine, a fan sucks in air. If you look head-on at a jet engine on a passenger jet aircraft, you can see the blades of this fan. The air is then retained inside the engine, where a compressor places it under pressure. The compressor contains more fans, all of which are fitted with blades and fastened to a shaft.

After these fans have done their work of compressing the air, fuel is introduced. The mixer helps to make the engine quieter.

Sir Isaac Newton in the 18th century was the first to theorize that a rearward-channeled explosion could propel a machine forward at a great rate of speed. This theory was based on his third law of motion. As the hot air blasts backwards through the nozzle the plane moves forward.

Henri Giffard built an airship which was powered by the first aircraft engine, a three-horse power steam engine. It was very heavy, too heavy to fly. In , Felix de Temple , built a monoplane that flew just a short hop down a hill with the help of a coal fired steam engine. Otto Daimler , in the late 's invented the first gasoline engine. In , American Hiram Maxim tried to power his triple biplane with two coal fired steam engines.

It only flew for a few seconds. The early steam engines were powered by heated coal and were generally much too heavy for flight. American Samuel Langley made a model airplanes that were powered by steam engines.

In , he was successful in flying an unmanned airplane with a steam-powered engine, called the Aerodrome. It flew about 1 mile before it ran out of steam. He then tried to build a full sized plane, the Aerodrome A, with a gas powered engine. In , it crashed immediately after being launched from a house boat.

In , the Wright Brothers flew, The Flyer , with a 12 horse power gas powered engine. From , the year of the Wright Brothers first flight, to the late s the gas powered reciprocating internal-combustion engine with a propeller was the sole means used to propel aircraft. It was Frank Whittle , a British pilot, who designed and patented the first turbo jet engine in The Whittle engine first flew successfully in May, This engine featured a multistage compressor, and a combustion chamber, a single stage turbine and a nozzle.

At the same time that Whittle was working in England, Hans von Ohain was working on a similar design in Germany. The first airplane to successfully use a gas turbine engine was the German Heinkel He , in August, It was the world's first turbojet powered flight. It was the XPA experimental aircraft that first flew in October, The basic idea of the turbojet engine is simple. Air taken in from an opening in the front of the engine is compressed to 3 to 12 times its original pressure in compressor.

The resulting hot air is passed through a turbine, which drives the compressor. If the turbine and compressor are efficient, the pressure at the turbine discharge will be nearly twice the atmospheric pressure, and this excess pressure is sent to the nozzle to produce a high-velocity stream of gas which produces a thrust.

Substantial increases in thrust can be obtained by employing an afterburner. It is a second combustion chamber positioned after the turbine and before the nozzle. The afterburner increases the temperature of the gas ahead of the nozzle.

The result of this increase in temperature is an increase of about 40 percent in thrust at takeoff and a much larger percentage at high speeds once the plane is in the air. The turbojet engine is a reaction engine. In a reaction engine, expanding gases push hard against the front of the engine.

The turbojet sucks in air and compresses or squeezes it. The gases flow through the turbine and make it spin. These gases bounce back and shoot out of the rear of the exhaust, pushing the plane forward.

A turboprop engine is a jet engine attached to a propeller. The turbine at the back is turned by the hot gases, and this turns a shaft that drives the propeller. Some small airliners and transport aircraft are powered by turboprops. Like the turbojet, the turboprop engine consists of a compressor, combustion chamber, and turbine, the air and gas pressure is used to run the turbine, which then creates power to drive the compressor.

Compared with a turbojet engine, the turboprop has better propulsion efficiency at flight speeds below about miles per hour. Modern turboprop engines are equipped with propellers that have a smaller diameter but a larger number of blades for efficient operation at much higher flight speeds. The fan, which almost always is made of titanium blades, sucks in tremendous quantities of air into the engine. The air moves through two parts of the engine.

Some of the air is directed into the engine's core, where the combustion will occur. The rest of the air, called "bypass air", is moved around the outside of the engine core through a duct. This bypass air creates additional thrust, cools the engine, and makes the engine quieter by blanketing the exhaust air that's exiting the engine. In today's modern turbofans, bypass air produces the majority of an engine's thrust.

The compressor is located in the first part of the engine core. And it, as you probably have guessed, compresses the air. The compressor, which is called an "axial flow compressor", uses a series of airfoil-shaped spinning blades to speed up and compress the air. It's called axial flow, because the air passes through the engine in a direction parallel to the shaft of the engine as opposed to centrifugal flow.

As the air moves through the compressor, each set of blades is slightly smaller, adding more energy and compression to the air. In between each set of compressor blades are non-moving airfoil-shaped blades called "stators". These stators which are also called vanes , increase the pressure of the air by converting the rotational energy into static pressure. The stators also prepare the air for entering the next set of rotating blades. In other words, they "straighten" the flow of air. The combustor is where the fire happens.

As air exits the compressor and enters the combustor, it is mixed with fuel, and ignited. It sounds simple, but it's actually a very complex process. The case contains all the parts of the combustor, and inside it, the diffuser is the first part that does work. The diffuser slows down the air from the compressor, making it easier to ignite. The dome and swirler add turbulence to the air so it can more easily mix with fuel. From there, the liner is where the actual combustion happens.

The liner has several inlets, allowing air to enter at multiple points in the combustion zone. The last main part is the igniter, which is very similar to the spark plugs in your car or piston-engine airplane.