CHAPTER 1
JET ENGINE THEORY AND DESIGN
CHAPTER OBJECTIVES
After completing this chapter, you will be able to:
Identify the two types of engine designation
State the theory of jet propulsion.
standards.
Identify the common terms and variables
Identify the different types of engines and their
major assemblies.
effecting engine performance.
the velocity of the water, giving us the term,
Every rating or specialty has a language of
its own. The Aviation Machinist's Mate is no
"a jet of water."
different. To be a good technician, you must learn
Another example of the theory of jet propul-
and understand the language (terms and theories)
sion is an inflated balloon. With the opening in
necessary for a thorough understanding of your
the balloon closed (fig. 1-1) there is no action
specialty. With this basic understanding, you will
because the pressure of the gas inside the balloon
develop the skills to recognize, analyze, and
is equal in all directions. When you allow the
correct problems with jet engines. Without it, you
become a "parts changer" unable to recognize
possible reasons for the problem and analyze
them.
This chapter explains the basics necessary for
the Aviation Machininst's Mate to build a strong
foundation. You'll learn the theory, terms, types
of engines, and major parts of jet engines.
BASIC THEORY OF
JET PROPULSION
Jet propulsion is the propelling force gen-
erated in the direction opposite to the flow
of a mass of gas or liquid under pressure.
The mass escapes through a hole or open-
ing called a jet nozzle. A familiar example
is the nozzle at the end of a fire hose. The
nozzle forms a smaller passageway through
Figure 1-1.-Balloon example of restricting jet propulsion.
which the water must flow. The nozzle increases
1-1
