A turbojet engine is a gas turbine device in which thrust is created by converting energy (thermal) into kinetic gas flow. In this case, the resulting reaction is used as a driving force.
The turbojet engine has received the greatest distribution and efficiency in aircraft that are capable of developing high flight speeds (supersonic aircraft).
There are single- and double-circuit devices that are equipped with afterburners, which significantly increase take-off and flight thrust. At the same time, with a higher thrust indicator, the flight speed increases.
The breadth of application of turbojet engines is due to the relative simplicity of their design and low specific gravity. The unit consists of a combustion chamber, a turbine,compressor and exhaust nozzle, which is a narrowing pipe that is located inside the exhaust manifold.
The air acquires a preliminary increase in pressure in the intake (due to velocity pressure), which then rises in the compressor. This allows you to create favorable conditions for combustion processes and efficiently use heat. The allowable gas turbine inlet temperature depends on the heat resistance of the materials and the turbine cooling efficiency. An increase in air pressure and gas temperature is a characteristic feature of most types of gas turbine devices.
The turbojet engine used in unmanned and high-speed aircraft provides a significant increase in thrust in afterburner modes, and, consequently, propulsion power when reaching supersonic speed. However, the units used in the field of subsonic flights are inferior to other types of gas turbine engines in terms of thrust parameters and efficiency.
This circumstance is due to the principle of operation of the device, which is associated with relatively high losses of heat and high-speed energy with the exhaust jet at low flight numbers (M).
It is not easy to assemble a turbojet engine with your own hands, for this you need to thoroughly know its structure and the principles of operation of all elements.
The instrument includes a gas compressor system which is located between the chambers and the inlet. Thanks to the energy generated by the combustion of fuel, the turbine drives the compressor and provides thrust.
Detailed schemes and calculations of the components of the propulsion system, as well as piston engines, are very diverse. In various sources, you can find detailed calculations and simple descriptions for these systems, which allows you to make a homemade turbojet engine.
Units with centrifugal pumps do not have an afterburner. Gases leaving the turbine enter the jet nozzle, after which they flow into the atmosphere at high speed. Thrust is created by increasing the speed of the gases leaving the engine.
