Read the text and do the tasksEngine designingТо move and fly any aircraft demands power. A machine that
produces mechanical power necessary for propulsion of a vehicle is
called an engine. It is constant engine evolution that decidedly
influences the aircraft performance.The process of developing an engine is one of compromises.
Therefore, creating engines begins with solving very complex and
contradictory problems – determination of the most optimum
parameters permitted by modern science in the engine operating
process. Then the designers work at developing such engine
constructions that could accomplish this process without
unnecessary loss and would have the long life and the high strength.
Engineers design specific attributes into engines to achieve specific
goals. Aircraft are one of the most demanding applications for an
engine, presenting multiple design requirements. An aircraft engine
must be:reliable – aircraft engines must perform reliably at high
pressure, all temperatures and speeds;lightweight – a heavy engine increases the empty weight of the
aircraft and reduces its payload; powerful – to overcome the weight and drag of the aircraft;small and easily streamlined – large engines with the
substantial surface area, when installed, create too much drag,
wasting fuel and reducing power output;repairable – to keep the cost of replacement down; fuel efficient – to give the aircraft the range the design
requiresThe design of aircraft engines tends to favor reliability over
performance. Long engine operation times and high power settings,
combined with the requirement for high reliability, mean that engines
must be constructed so that they could support this type of operation with ease. Aircraft spend the vast majority of their time traveling at
high speed. This allows an aircraft engine to be air cooled. The amount
of air flow an engine receives is usually designed according to the
expected speed and altitude of an aircraft in order to keep engine
working at its optimal temperature.Besides, engine designers, experts in the field of automatic
control, measuring and information systems also take part in
developing engines. They make every effort to get units that could
meet all modern requirements.Today we speak about the necessity to create nuclear,
plasma, ion and other exotic engines. It is also quite necessary to
have "clean" aircraft power plants, that is, aviation engines which
do not contaminate the environment due to usage of hydrogen as the
main fuel. Aircraft engine building is a fast developing branch of
industry. The engine complexity doubles every 15 years. Aircraft
engine designers must be well educated and able to solve the most
difficult problems by using all modern knowledge, techniques and
facilities.Are the sentences true or false?1. Aircraft engines are designed to be heavy to increase the aircraft's payload.