Английский язык. Писарева Л.П. - 31 стр.

in turn, drives a centrifugal compressor, which increases the air pressure before the
reciprocating scavenging air pumps. Since the density of the scavenging air is increased
by the pressure rise in the turbo-compressor and the subsequent cooling, a larger
quantity of air by weight is entrapped in the cylinder which, in turn, permits the
combustion of a larger quantity of fuel and gives a higher available output. Each turbo-
charger consists of a single stage or two-stage centrifugal compressor and an axial
turbine which are assembled on the same shaft. Rotation of the rotor depends on the
engine load and scavenging resistance, since the unit is connected to the engine without
any mechanical transmission. The turbocharged engine is maneuvered in the same
manner as a normally aspirated engine. Make engines use only pulse turbocharging and
to meet this requirement cylinder numbers which permit good grouping of the
turbocharger connections are employed. A distinction is made between three-pulse
charging for 6-9-and 12 cylinder engines with cams specially timed for three-pulse
mode, and four-pulse charging for B- and 16 cylinder engines with completely different
timings for the four-pulse mode. The disadvantage of pulse charging for highly-
supercharged engines compared with the constant pressure charging is the fact that
during the full load the single-stage exhaust turbine can only utilize the lower part of
the very high exhaust gas pressure wave. But this is an advantage at part load or
reduced power. Pulse charging has further advantages that the engine can adapt very
quickly to sudden changes in load.


                                        Exercises

I. Прочтите и переведите текст письменно.
II. Переведите письменно предложения, обращая внимание на модальные
глаголы и их заменители.
    1. The power of any engine can be increased by burning more fuel in the cylinder.
    2. The fuel pumps must have a definite phase relation to the engine crankshaft.
    3. There has been a great improvement of late years in the matter of engine
       designing so that component parts may be removed and replaced easily.
    4. The term “overall efficiency” should be understood to mean more than just
       specific fuel consumption.
    5. The worn down rings are to be replaced by new ones.
    6. When the wear reaches the allowable level, the cylinder has to be rebored and
       resurfaced or has to have a new liner fitted.



   III.   Исправьте те предложения, которые искажают смысл текста.
          Запишите правильный вариант. Переведите.

   1. Engine output is increased due to the fact that it is connected to an air cooler.
   2. The turbocharged engine operates at a decreased pressure level.
   3. The combustion of a larger quantity of fuel gives a lower output.
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