The document summarizes how gas turbine engines work. It describes that gas turbine engines have three main parts: a compressor that pressurizes incoming air, a combustion area that burns fuel to produce hot gas, and a turbine that extracts energy from the gas to power the compressor and provide output. The document outlines the basic process of how air is compressed, fuel is burned to heat the air, and the hot gas spins the turbine before exiting. It also provides examples of different types of gas turbine engines and their applications in aircraft, power plants, and tanks.
2. Introduction
Most commercial jets are
powered by turbofan
engines, and turbofans
are one example of gas
turbine engines.
You may have never
heard of gas turbine
engines, but they are
used in all kinds of un
expected places.
3. Types of Turbine
There are many different
kinds of turbines:
Steamturbine. The steam
runs through a huge and
very carefully designed
multi-stage turbine to spin
an output shaft that drives
the plant's generator.
4. Hydroelectric dams
use waterturbines in
the same way to
generate power. This
turbines look
completely different
from a steam turbine
because water is so
much denser (and
slower moving) than
steam, but it is the
same principle.
5. Wind turbines, also
known as wind mills, use
the wind as their motive
force. A wind turbine
looks nothing like a
steam turbine or a water
turbine because wind is
slow moving and very
light, but again, the
principle is the same.
6. A gas turbine is using the
same concept. In all modern
gas turbine engines, the
engine produces its own
pressurized gas, and it does
this by burning something like
propane, natural gas,
kerosene or jet fuel. The heat
that comes from burning the
fuel expands air, and the high-
speed rush of this hot air spins
the turbine.
7. Part of Gas Turbine Engine
Gas turbine engines are, theoretically, extremely simple.
They have three parts:
Compressor- Compresses the incoming air to high
pressure
Combustion area - Burns the fuel and produces high-
pressure, high-velocity gas
Turbine - Extracts the energy from the high-pressure,
8. Compressor
The compressor is
basically a cone-shaped
cylinder with small fan
blades attached in rows.
Assuming the light blue
represents air at normal
air pressure, then as the
air is forced through the
compression stage its
pressure rises
significantly. The high-
pressure air produced by
the compressor is shown
10. Axial vs. Radial
Axial
Advantages:
simple and
inexpensive
light weight
Disadvantages:
less efficient
large frontal area
limited compression
ratio (4:1 ratio)
• RadialRadial
– Advantages:Advantages:
•efficientefficient
•highhigh
compressioncompression
ratios (20:1)ratios (20:1)
– Disadvantages:Disadvantages:
•complexcomplex
•expensiveexpensive
11. GTE AIR
Compressed Air Distribution:
– Primary Air - 30% of
the compressed air is
supplied directly to the
combustion chamber
– Secondary Air - 65% of
the air provides cooling
for the combustion
chamber
– Film Cooling Air - 5%
of the air provides
cooling directly to the
turbine blades
12. Combustion Area
The high-pressure air then
enters the combustion area,
where a ring of fuel injectors
injects a steady stream of
fuel. The special piece that
located in combustion area
called a "flame holder," or
sometimes a "can." The can
is a hollow, perforated piece
of heavy metal.
The injectors are at the right.
Compressed air enters
through the perforations.
Exhaust gases exit at the left.
13. Turbine
At the far left is a final
turbine stage, shown here
with a single set of vanes.
It drives the output shaft.
This final turbine stage
and the output shaft are a
completely stand-alone,
freewheeling unit. They
spin freely without any
connection to the rest of
the engine. And that is the
amazing part about a gas
turbine engine.
14. Gas Turbine Cycle
The cycle usually
describes the
relationship between the
space occupied by the
air in the system. The
Brayton cycle (1876),
shown in graphic form as
a pressure-volume
diagram, is a
representation of the
properties of a fixed
amount of air as it
passes through a gas
turbine in operation.
15. Advantages of Gas Turbine
Engines
There are two big advantages of the turbine over the
diesel:
Gas turbine engines have a great power-to-weight
ratio compared to reciprocating engines. That is, the
amount of power you get out of the engine compared
to the weight of the engine itself is very good.
Gas turbine engines are smallerthan their
reciprocating counterparts of the same power.
16. Disadvantages of Gas Turbine
Engines
The main disadvantage of gas turbines is
that, compared to a reciprocating engine
of the same size,
They are expensive
Tend to use more fuel when they are
idling
They prefer a constant rather than a
fluctuating load.
18. What is the Goal of Gas Turbine
Engine in Aircraft
The goal of a turbofan engine is to
produce thrust.
Generated under Newton's Third Law.
Generally measured in pounds in the
United States.
19. How Thrust can be Produce?
http://www.grc.nasa.gov/WWW/K-12/airplane/ngnsim.html
21. GENX
The GEnx is expected to produce thrust from 53,000
to 75,000 lbf (240 to 330 kN). Boeing predicts reduced
fuel consumption of up to 20%.
Type Turbofan
Manufacturer GE Aviation
First run 2000s
Major
applications
Boeing 747-8
Boeing 787
Developed
from
General Electric
GE90
22. CCGT Power Plant
The Combined Cycle power plant is a combination of a fuel-fired turbine
with a Heat Recovery Steam Generator (HRSG) and a steam powered
turbine. These plants are very large, typically rated in the hundreds of
mega-watts.
Depending on the power requirements at the time, the combined cycle
plant may operate only the fired turbine and divert the exhaust.
23.
24. M-1 Tank
Engine
Honeywell AGT1500C
multi-fuel turbine engine
1,500 hp (1,119 kW)
Power/weight 24.5 hp/metric ton
Transmission Allison DDA X-1100-3B
Fuel capacity 500 gal (1,892 liters)
Operational
range
289 mi (465.29 km)
With NBC system: 279 mi
(449.19 km)
Speed
Road: 42 mph (67.7 km/h)
Off-road: 30 mph (48.3
km/h)
26. Thank You For YourThank You For Your
AttentionAttention
Notes de l'éditeur
Because they spin at such high speeds and because of the high operating temperatures, designing and manufacturing gas turbines is a tough problem from both the engineering and materials standpoint. That makes gas turbines great for things like transcontinental jet aircraft and power plants, but explains why you don't have one under the hood of your car.
(the metric system uses Newtons, where 4.45 Newtons equals 1 pound of thrust)