How Does a Jet Engine Work?

A jet engine is an engine that directly generates a reactive thrust by the airflow sprayed from the nozzle at high speed. It is widely used as a power unit of an aircraft. The fuel and oxidant react with each other in the combustion chamber to release thermal energy. Then the thermal energy is converted into the function of adjusting the air flow in the nozzle. In addition to fuel, oxidants carried by aircraft are called rocket engines, including solid fuel rocket engines and liquid fuel rocket engines. It is characterized by its ability to work outside the atmosphere. "Air jet engines" that draw air from the atmosphere without oxidants as oxidants include ram engines, pulse engines, turbojet engines, and turbofan engines. The most commonly used air jet engines in modern air transport aircraft are turbofan engines. It is characterized by large thrust, low noise and low fuel consumption. ^[1]

Jet engine

A jet engine is an engine that directly generates a reactive thrust by the airflow sprayed from the nozzle at high speed. It is widely used as a power unit of an aircraft. The fuel and oxidant react with each other in the combustion chamber to release thermal energy. Then the thermal energy is converted into the function of adjusting the air flow in the nozzle. In addition to fuel, oxidants carried by aircraft are called rocket engines, including solid fuel rocket engines and liquid fuel rocket engines. It is characterized by its ability to work outside the atmosphere. "Air jet engines" that draw air from the atmosphere without oxidants as oxidants include ram engines, pulse engines, turbojet engines, and turbofan engines. The most commonly used air jet engines in modern air transport aircraft are turbofan engines. It is characterized by large thrust, low noise and low fuel consumption. ^[1]

Different types of jet engines, whether ramjet, pulsejet, gas turbine, turbo / ramjet or turbo-rocket, differ only in the "thrust provider", the way the engine supplies energy and converts it into flight power.

Since the 17th century, some people have tried to use steam power or internal combustion engines to achieve jet engines that can be used, such as the Dutch physicist Huygens, and later the Romanian Henry Coanda 1910. But all ended in failure.

At this time people began to try hybrid jet engines. A conventional piston engine is used to drive the fan to compress the air and ignite the gas in the space behind. Examples include the Coanda 1910, Campini Caproni CC.2, and the Jin-11 engine used by the Kamikaze commando in Japan. An attempt of this era is called a thermal jet engine (Moterjet). Although this engine has a simple structure, it has a large weight, insufficient thrust, and poor practicality.

The key to solving the problem is to use a gas-driven turbine to drive the compressor, which can eliminate the unnecessary piston engine in the hot jet engine and provide greater thrust. Such an idea is similar to a gas turbine. In 1903 the Norwegian & AElig; gidius Elling invented the gas turbine. However, this technology cannot be applied to jet engines, because materials at the time could not produce such engines, and there were still many problems in terms of safety and continuous work.

Other solutions are also underway at this time. In 1915, Albert Fonó of the Austro-Hungarian Empire designed a device to increase the range of artillery shells by using gas and compressed air. This device provides thrust by compressing and igniting the airflow of the shell during high-speed flight through a variable-section air inlet. The Austro-Hungarian Army eventually did not adopt its design, so he registered a patent for a supersonic stamping engine in Germany in 1928 and was approved in 1932. The stamping engine was born.

In 1921, Frenchman Maxim Guillaume patented the first jet engine. His design is similar to an axial jet engine. In 1923, a report issued by the National Bureau of Standards questioned the role of jet engines. The report believed that jet engines were of little economic value for low-altitude flight at the time, and even stated that "now it seems that any possible jet thruster has no practical value, even for military purposes.

In 1928, Frank Whittle of the Royal Air Force College of Cromwell, England, proposed a new jet engine design. In January 1930, Whittle filed a patent for the design of a jet engine and was granted a patent in 1932. Whittle's design is to place a two-stage axial compressor in front of a large centrifugal compressor and be driven by a turbine. Later, Whittle removed the previous axial compressor and used a larger centrifugal compressor. This engine was tested in 1937 but was unsuccessful due to a fuel leak failure. Because the British government was not interested, Whittle's design was put on hold.

At the same time, Germany's Hans von O'An carried out a completely independent design in Germany. At first, the engine of Ou'an was driven by electricity. His purpose was only to demonstrate the feasibility of this engine. Oran later joined Henkel, which was looking for a jet engine design, and trial-produced a new engine. The new engine initially used hydrogen as fuel and later switched to ordinary aviation fuel. He can provide 5kN thrust. On August 27, 1939, pilot Erich Warsitz took off from the Rostock-Marienehe airport with a He-178 equipped with an Oran jet engine. This is the first jet aircraft in human history.

Both British jet fighters using centrifugal jet engines and German fighters using rocket and axial jet engines participated in battles in the late World War II. The more advanced German jet fighter has achieved excellent results. This prompted the aircraft to quickly shift to the jet era in later times.