turbine. As an AD, you will work with the gas
tends to move at a constant speed, in a straight
turbine engines. Under jet turbine engines are four
line unless acted upon by some external force."
types: turbojet, turboprop, turbofan, and turbo-
Newton's second law states "An unbalance of
shaft. There are 2 engine designation systems in
force on a body tends to produce an acceleration
use today to identify the different types of gas
in the direction of force, and that acceleration,
turbine engines.
if any, is directly proportional to the force and
inversely proportional to the mass of the body."
The law simply stated is "force is proportional
TURBOJET
to the product of mass and acceleration."
or
Turbojet engines are the basis for all other gas
turbine engines. We already know their cycle. Air
is drawn into the turbojet engine compressed,
where
mixed with fuel, and burned continuously.
The exhaust product of this burning operates
F = force, in pounds;
the turbine, for the compressor, producing
M = mass, in slugs; and
thrust which propels the aircraft. Adding fans,
propellers, or free turbines, change the basic
A = acceleration, in feet per second per second.
turbojet into a turboshaft, turboprop, or turbo-
His third law states that "for every acting
fan.
force (action) there is an equal and opposite
reacting force (reaction)." We learned this
principle earlier with the rocket.
Turboshaft
Turboshaft engines use the free turbine
JET ENGINE TYPES AND
DESIGNATIONS SYSTEMS
turbine and a power turbine. The power turbine
(fig. 1-11) drives the helos rotor blades, through
We learned the four basic types or classes of
drive shafts and gearboxes.
jet engines: rocket, pulsejet, ramjet and jet
Figure 1-11.-Turboshaft engine.
1-7
