A turbojet engine is one of the most important mechanisms, which was invented in the twentieth century. Talk that accompanied this discovery, what are the models of this device today, and is it possible to make it yourself.
A bit of history
When in 1903 the first Wright brothers plane with piston internal combustion engines rose into the air, Soviet scientist Konstantin Tsiolkovsky wrote a work on the use of jet thrust to overcome gravity. It was the basic ideas of the theory of jet propulsion. As is always the case with brilliant discoveries, his work was not taken seriously. Only decades later was destined to come true that scientist have long been recorded on paper.
It so happened that the turbojet engine was adopted for series production in Germany in the late thirties. The project was attended by such famous companies as "Heinkel", "BMW", "Daimler-Benz" and "Porsche". But the main producer was still "Jankers".
Despite the success, to develop this direction at the time did not.
In the Soviet Union started development of the aircraft designer Arkhip Lyulka. In the first half of the fortieth year, he patented the scheme, which was a turbojet engine. Unfortunately, the government did not support the scientist, although he later received worldwide recognition. Arkhip Cradle was ordered to do tank research. For turbojet engines, he came back only after they appeared in Germany.
The first engine tests were carried out in 1947.
The principle of operation
Turbojet engine operates as a conventional heat engine. Without going into details, the mechanism could be described as designed to convert energy into mechanical work. The gas inside the device has power. Compressing the working fluid receives it, and when the expansion is converted into useful work.
Energy and follow-up work to compress the gas must always be less than that required for the expansion. Otherwise the conversion will fail. Therefore, prior to expansion the gas is heated and before compression is cooled. Then as a result of heating could have some excess energy that use to produce mechanical work.
The working body of the engine consists of:
- the compressor serving to compress air
- combustion chamber for heating
- turbine for expansion.
The cooling effect provided by the atmosphere.
In the compressor there are disks of metal, while their crowns are located the blades that capture air outside and moved inside.
From the compressor the air passes into the combustion chamber, heating up and mixing with kerosene, falling back through the rotor.
Then the action moves to the turbine, where the gas spins like a toy prop. Turbines usually have three to four stages. It is this mechanism accounts for the greatest burden. Turbojet engine rotates at a speed of thirty thousand revolutions per minute. Torch coming out of the combustion chamber may have a temperature of up to a thousand degrees Celsius. The air, expanding here, begins to move the turbine.
After that, in a jet nozzle, the working fluid reaches a speed greater than the speed of oncoming flow. This is how jet thrust is obtained.
TRD or turbojet engine, the principle of operation of which is described above, belongs to the class of gas turbines. It happens:
- Turbojet with afterburner
- dual circuit turbofan;
- dual-circuit turbojet engine with afterburner.
At present we know five generations of jet engines. The first are those that were used in the years of the war the British and Nazi forces. In the second generation there were axial compressor afterburning chamber and air inlet adjustable. In the third — increased compression in the fourth — were able to raise the operating temperature. The fifth generation in the domestic development has increased power and better maneuverability. The units are designed for fighter aircraft, produced at the Ufa plant.
Do-it-yourself turbojet engine
The Amateur modelers who want to assemble an engine yourself, today offers a complete range of all spare parts. In sale there are special kits (e.g., Kit). The turbine can be purchased as ready to do so themselves. The last option is quite troublesome and can also cost a pretty penny. That's the hardest part for those who collect turbojet engine with your hands, as this will require turning and milling installation, and the welding device.
Before manufacturing, it is worthwhile to study the theory of micro TRD. For this there are special manuals, where calculations and drawings are given.
And then, you can begin the path to aero modeling.