Jet engine is a direct reaction propulsion device. Low-speed working fluids (air and fuel) are pressurized and burned, and then sprayed out at high speed, which directly produces reaction force. Compared with piston engine, jet engine is far superior to the former in weight and high-speed performance. In fact, as early as 19 13, French engineer Rennes Roland won the world's first patent for jet engine. Its working principle is that air enters from the air inlet, burns in the combustion chamber after passing through the oil supply system, and then ejects from the propulsion nozzle to generate thrust. This principle is very similar to today's ramjet engine, but due to the limitations of material technology and manufacturing level at that time, it could not be produced.
Working principle of jet engine
Until 1937~ 1938, British whittle and German Ohain added the compressor design to the engine designed by Ryan Roland, respectively, which realized the pressurization of the air entering the inlet, thus developing a more practical and efficient gas turbine engine. This engine is mainly composed of air intake device, compressor, combustion chamber, gas turbine and exhaust nozzle. Its working principle is: after air enters the engine from the air intake device, it is compressed and supercharged by the compressor, then it enters the combustion chamber and burns with the injected aviation kerosene to form high-temperature and high-pressure gas, and then it enters the gas turbine to expand and do work, which drives the turbine to rotate at high speed to output the power needed to drive the compressor and other accessories of the engine, and the gas ejected by the gas turbine generates the thrust of the engine.
1939 On August 27th, a He- 178 was equipped with the HeS3B engine improved by Ohain, which successfully carried out the first human jet flight, thus announcing the beginning of the jet flight era. This HeS3B engine is an improvement of HeS 1 engine originally designed by Ohain, and the bench thrust is increased from 265daN to 490daN.
After the Second World War, with the rapid development of science and technology, on the basis of the success of whittle and Ohain, the family of gas turbine engines in aero-engines grew rapidly, and turboprop engines, turboshaft engines, turbofan engines and turbofan engines appeared one after another, and by virtue of their performance far exceeding that of piston engines, they are still the main force to promote aircraft flight. In addition, in addition to the aviation industry, gas turbines are also widely used in shipbuilding, electric power and other industries, and become an important engine to promote social progress and development.
refer to
1. Yan Xiaojun. Comparative analysis of typical aero-engine structures [M]. Beijing: Beijing University of Aeronautics and Astronautics Press, 2011;
2. Chen Guang Liu Daxiang. Aeroengine: the heart of an airplane [M]. Beijing: Aviation Industry Press, 2003;
3. Liu Changfu, Deng Ming. Structural analysis of aeroengine [M]. Xi 'an: Northwestern Polytechnical University Press, 2006.