Grammar: Future Indefinite Tense. Text: Turboprops New words to the text

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Turboprops

If a gas generator (turbojet) turns an aircraft propeller through a system of gears, it becomes a turboprop (see Fig. 3). The propeller-drive reduction gearing may be driven by the shaft from the same turbine that rotates the compressor, or the gearing may be driven by a shaft from a so-called free turbine that rotates independently in the exhaust gas stream of the basic gas generator. In either case, the gas generator for a turboprop might be either a single- or dual-compressor type, although, as this is written, there are no dual-axial compressor turboprops in production.

Although a turboprop is more complicated and heavier than a turbo-jet engine of equivalent size and power, it will deliver more thrust up to medium-high subsonic airspeeds. However, the advantage decreases as flight speed increases. In normal cruising-speed ranges, the propulsive efficiency (output divided by input) of a turboprop remains more or less constant, whereas the propulsive efficiency of a turbojet increases rapidly as airspeed increases. The spectacular performance of a turboprop during take-off and climb is the result of the ability of the propeller to accelerate a large mass of air while the aircraft is' moving at relatively low ground and flight speed.

(to be continued)

New words to the text:

gearing ['gɪərɪŋ] зацепление; зубчатая передача, привод; редуктор

shaft [ʃɑ:ft] вал; шпиндель; ось; тяга;

so-called [,səu'kɔ:ld] так называемый, известный под именем/названием

Syn: inappropriately named, supposed, alleged,

presumed, reputed ; dual-axial

thrust up пробиваться (о растениях)

cruising-speed крейсерская скорость; экономическая скорость;

экономическая скорость; эксплуатационная

скорость

whereas (h)weə'ræz] тогда как; несмотря на то, что; принимая во

внимание, поскольку

accelerate [ək'seləreɪt] ускорять, увеличивать скорость; пускать в ход