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Main Parts of the Gas Turbine Engine and their functions
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Essential Vocabulary
| 1. working fluid 2. to accelerate 3. to increase 4. velocity 5. conversion 6. efflux 7. rotary air compressor 8. air intake 9. exhaust outlet 10. centrifugal compressor 11. axial flow compressor 12. to drive (drove, driven) 13. to couple 14. shaft 15. to diffuse 16. frontal area 17. pressure ratio 18. to attain 19. to burn (burnt) 20. quantity 21. fuel burner 22. volume of air 23. to supply 24. to expand 25. smooth stream 26. to release 27. blade 28. (exhaust) nozzle 29. accessories 30. to extract energy 31. to involve 32. blade tips 33. flow of gas 34. row 35. stationary nozzle guide vanes 36. moving blades 37. assembly 38. discharge gases | - рабочее тело - ускорять - увеличивать - (векторная) скорость - преобразование - истечение - роторный компрессор - воздухозаборник - выхлопное устройство - центробежный компрессор - осевой компрессор - приводить в движение - соединять - вал - рассеивать, распространять - лобовая площадь - степень сжатия - достигать - жечь, сжигать - количество - топливная форсунка - количество воздуха - снабжать, подавать - расширять - ровный поток - выпускать, освобождать - лопатка - (выхлопное) сопло - вспомогательные агрегаты - выделять энергию - вовлекать, включать в себя - законцовки лопасти - поток воздуха - ряд - неподвижные направляющие лопатки соплового аппарата - вращающиеся лопатки - агрегат - выхлопные газы |
Text: Main Parts of the Gas Turbine Engine
The gas turbine engine is essentially a heat engine using air as the working fluid to provide thrust. To achieve this, the air passing through the engine has to be accelerated; this means that the velocity or kinetic energy of the air is increased. To obtain this increase, the pressure energy is first of all increased, followed by the addition of heat energy, before final conversion back to kinetic energy in the form of a high velocity jet efflux.
The gas turbine engine consists of a rotary air compressor with an air intake, one or more combustion chambers, a turbine, and an exhaust outlet.
There are two basic types of rotary air compressors: centrifugal flow and axial flow compressors. Both types are driven by the engine turbine and are coupled direct to the turbine shaft. The function of the compressor is to accelerate the air, to diffuse it and to produce the required pressure rise.
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The axial compressor consumes far more air than a centrifugal compressor of the same frontal area and can be designed to attain much higher pressure ratios. Since the airflow is an important factor in determining the amount of thrust, this means that the axial compressor engine will also give more thrust for the same frontal area.
The combustion chamberhas the difficult task of burning large quantities of fuel supplied through the fuel burners with extensive volumes of air supplied by the compressor. The heat is released in such a manner that the air is expanded and accelerated to give a smooth stream of uniformly heated gas at all conditions required by the turbine. This task must be accomplished with the minimum loss in pressure and with the maximum heat release.
The turbine has the task of providing the power to drive the compressor and accessories. It does this by extracting energy from the hot gases released from the combustion system and expanding them to a lower pressure and temperature. High stresses are involved in this process, and for efficient operation, the turbine blade tips may rotate at speeds over 1,500 feet per second. The continuous flow of gas to which the turbine is exposed may have an entry temperature between 850 and 1,700 deg. С and may reach a velocity of over 2,500 feet per second in parts of the turbine.
The turbine may consist of several stages. Each stage employs one row of stationary nozzle guide vanes and one row of moving blades.
The exhaust systempasses the turbine discharge gases to atmosphere at a velocity and in the required direction to provide the resultant thrust.
Because the turbojet engine is a heat engine, the higher the temperature of combustion the greater is the expansion of the gases. The combustion temperature, however, must not exceed a value that gives a turbine gas entry temperature suitable for the design and materials of the turbine assembly.
The use of air-cooled blades in the turbine assembly permits a higher gas temperature and a consequently higher thermal efficiency.
Learn these phrases.
| 1. to accelerate the air 2. to increase the velocity 3. to drive the compressor 4. to couple to the turbine shaft 5. to diffuse the air 6. to reach a velocity 7. to burn large quantities of fuel 8. to supply by the compressor 9. to expand hot gases 10. to release hot gases 11. to extract energy 12. to provide thrust | - ускорять воздух - увеличить скорость - приводить в движение компрессор - соединять с валом турбины - рассеивать воздух - достигать скорости - сжигать большое количество топлива - доставлять компрессором - расширять горячие газы - освобождать (выделять) горячие газы - выделять энергию - создавать тягу |
Exercise 1. Guess the meaning of the international words.
Nouns
Gas, turbine, acceleration, energy, compressor, diffuser, factor, temperature, material, compression, process, accessory, pressure, stress, operation, system, atmosphere, efficiency.
Adjectives
Kinetic, final, centrifugal, frontal, minimum, maximum, stationary, resultant, thermal.
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