Aero Chapter 05/06 (TS) and 05 (ADV & IUT), Thrust and Thrust Curve Review
T-45 Aerodynamics Student Workbook
consumption, and a lower specific weight. The turbojet came first because it was simpler technology.
The turbofan engine is preferred in most modern applications.
The afterburner is a section added to some jet engines, which can provide a large thrust increase with
little weight. The afterburner section consists of another set of fuel spray nozzles, flame holders behind
the turbines, and variable exhaust nozzles. Since there are no highly stressed engine components
(turbine blades) behind the afterburner, a large amount of fuel can be burned there. Afterburners are a
very inefficient use of the fuel; however, as fuel flow will typically triple or quadruple in afterburner
operation for a 50% increase in thrust.
T-45 THRUST
A single Rolls-Royce
Air
F405-RR-401
Combustion
turbofan engine that
and Exhaust
develops an
installed static sea
Turbines
N1
N2
level thrust of 5,527
Compressor Compressor
N2
N1
Bypass Duct
pounds provides
thrust in the T-45.
Combustion
Exhaust
Referring to Figure
Section
Section
79, air enters the
engine directly at the
first stage of N1.
Between N1
components and N2
components (which
is typical of turbofan
engine design),
airflow is divided into
two paths, one of
Fan
which enters the N2
Bypass Duct
(Outboard)
compressor stage
and the other enters
Figure 79: T-45 TURBOFAN ENGINE
the annular bypass
duct. The airflow
from the N2 section then enters the combustion section where eighteen fuel spray nozzles provide fuel for
combustion. From the combustion section, the heated and accelerated airflow enters and flows through
the turbine section.
connection between the N1 and N2 sections.
Airflow from the turbine section then moves into the exhaust section. The heated and accelerated airflow
is mixed with the airflow from the annular bypass duct. The mixed airflow then is discharged through a
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