What is a jet engine?
Today we will talk about what isjet engine and what is its significance for modern aviation. Since his appearance on Earth, Man has been looking his way to the sky. With what incredible ease the birds soar in the ascending streams of warm air! And not only small specimens, but even such large ones as pelicans, cranes and many others. Attempts to imitate them, using primitive aircraft based on the muscular strength of the pilot himself, if they led to a kind of "flight", it was still impossible to massively implement the development - it was very unreliable constructions, too many restrictions were imposed on a person, their use.
Then there were internal combustion engines andpropeller motors. They were so successful that the modern jet engine and propeller-propeller engine still coexist in parallel. Of course, undergoing a number of modifications.
How did the jet engine
Most technical solutions, inventionwhich is attributed to a man, in fact, were peeped by nature. For example, the creation of a hang glider was preceded by the observation of the flight of birds hovering in the sky. The streamlined forms of fish and birds have also been brilliantly argued, but already within the framework of technical means. A similar story did not pass by the jet engine. This principle of motion is used by many marine life - octopus, squid, jellyfish, etc. Tsiolkovsky spoke about such an engine. Even more - he theoretically substantiated the possibility of creating a dirigible for flights in interplanetary space.
Jet propulsion lies at the core of missileengines. And the rockets were known even in ancient China. We can say that the idea of creating a jet engine "soared in the air" required only seeing it and embodying it in technology.
The structure of the engine and the principle of operation
At the heart of any jet engine is a camera withoutlet, ending with a bell-tube. Inside the chamber a fuel mixture is supplied, ignited there, turning into a gas of high temperature. Since its pressure spreads uniformly in all directions, pressing on the walls, then the gas can escape only through the bell, oriented in the opposite direction of the desired direction of motion. This creates a driving force. This is easier to understand by the example: on the ice is a man holding a heavy scrap in his hands. But if he pushes the scrap aside, he will receive an impulse of acceleration and slip on the ice in the opposite direction to the throw. The difference in the range of flight scrap and the displacement of a person is explained only by their mass, the forces themselves are equal, and the vectors are opposite. Making an analogy with a jet engine: a man is an aircraft, and a scrap is an overheated gas from the socket of the chamber.
For all its simplicity, this scheme hasseveral significant drawbacks - a large fuel consumption and huge pressure on the walls of the chamber. Various solutions are used to reduce consumption: liquefied gas and oxidizer are used as fuel, which, changing their state of aggregation, are more preferable than liquid fuel; another option is an oxidizable powder instead of a liquid.
But the best solution is straight flowjet engine. It is a through chamber, with an entrance and an exit (conditionally speaking - a cylinder with a bell). When the device moves into the chamber under pressure, the air of the external medium enters, heats up and contracts. The feed fuel mixture ignites and gives the compressed air an additional temperature. Further, it breaks through the bell and creates an impulse, as in a conventional jet engine. In this scheme, fuel is an auxiliary element, so its costs are significantly lower. It is this type of engine used in aircraft where you can see the blades of the turbine, which pumps the air into the chamber.