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Simple Reaction Engines
and Designation of Engines
the basic jet engines and how they operate. The
engines discussed in this chapter are different
from the turbojet engine in that they do not have
a compressor or a turbine. They must rely on
some other means of compressing their air. Even
though these engines are not suitable for either
the bomber or fighter aircraft, they are still used
in our Air Force for various jobs. In addition to
our study of basic jet engines, we will see how
the Air Force identifies jet engines.
8.
Ramjet
The ramjet engine (see fig. 15) is the simplest
of all reaction engines. It derives its name from
the ram effect used in the operation of the engine.
The ramjet engine is also called a continuous
thermal duct, athodyd (aero thermo
dynamic
duót), and the Lorin tube in
honor of R’ene
Lxii who patented the application of the princi-
pie about 1913.
No moving parts are incorporated in the assem-
biy of the ramjet engine.
Ip its simplest form,
the engine has the appearance of a tube or barrel
which is open at both ends. Major features and
sections of the engine are the chamber, fuel nozzle,
ignitor plugs, and nozzle. The chamber is divided
into a forward diffuser section, the combustion
section of the chamber, and the nozzle.
Operation of the Power Unit. This
engine does
not have a compressor. This power plant must
be forced through the air at high speed in order
that it can obtain its oxygen supply for combus-
tion. In some engines the speed required to
supply this air mass is around 350—400 mph, or
higher.
When the quantity of air needed for operation
is achieved, fuel is injected and mixed with the
air, after which ignition and combustion take
RAM AIR
DUCT
COM BUST ION
CHAMBER
NOZZLE
RAM JET
Figure 15. Ramjet engine.
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