Conference Session B4
Paper 2144
GEnx: THE ENGINE OF INNOVATION
Yevgeniy Riftin (yer2@pitt.edu) and Sean Hart (sth41@pitt.edu)
Abstract - Turbofan engineering used to be largely based on
increased power and aircraft range, while maintaining an
exceptional degree of safety [1]. However, with rising
natural resource and fuel costs along with increasing public
awareness of emission of nitrous oxides and of the carbon
footprint left by extensive fossil fuel use, the lack of
innovation in the efficiency of turbofans has become more
prominent. Engineers have been researching new designs
for turbofans, which increase efficiency in the cost and
operation of the turbofan, while maintaining the same
degree of power [2]. This collective research has led to the
development of the General Electric GEnx turbofan. The
GEnx is one of the greatest leaps in jet engine engineering,
utilizing modern technologies, materials, and designs [2].
This paper addresses innovations in the engineering of the
components of the GEnx turbofan, specifically the fan and
the propulsor. This paper addresses how a new fan design,
and materials that compose the fan blades and casing have
led to an engine with increased efficiency and power.
Additionally, the paper will discuss innovations in the
engineering of the GEnx propulsor, which consists of the
compressor, combustor, and turbine, and how these
innovations of the propulsor led to fewer moving parts with
an increased pressure ratio, an optimal fuel-air mixture, and
an efficient airflow. Through the discussion of the innovation
of the GEnx turbofan components, and their impact on the
performance of the engine, our paper provides an
understanding on the impact the GEnx will have on the
airline industry and the associated operational costs of
turbofans.
efficiency. Up until now, there has yet to be an engine that
can meet the demand for a balance of efficiency and power.
The GEnx turbofan has filled this void.
THE NEWEST GENERATION OF TURBOFANS
The class of engine that the GEnx falls into is called a
‘turbofan’, specifically a high-bypass turbofan, and it
consists of, as its name implies, with many rotating turbines
and a large frontal fan. Typically the large fan at the front of
the engine provides the large majority of thrust, while the
rest of thrust is provided by propulsor of the engine that is
located in the rear. The propulsor is able to provide thrust
through a compressing and combusting air that is fed into it.
While the thrust provided by the propulsor is strong it is not
as efficient as thrust from the fan. While designing the
GEnx, engineers wanted to get the best of both worlds, an
engine that is both powerful and efficient; what they have
done is just that. The GEnx sets the new standards for a
turbofan engine. It is able to achieve this through a handful
of innovative changes to the design of the typical turbofan
engine.
With a revolutionary new fan design and
innovations like the TAPS combustor, the GEnx is truly an
engine of the twenty-first century.
SPINNING THE SKIES: THE GENX FAN
The front most component of the GEnx engine is the fan.
The fan works just like any other fan; it consists of many
rotating blades and a casing in which it is contained. The
role of the fan in the GEnx, or any other turbofan engine, is
to intake large amounts of air and expel it at the rear of the
engine providing thrust. What separates the GEnx from the
other turbofans is its high bypass ratio. The term bypass ratio
is commonly used in aviation to describe the mass of air that
is taken in by the fan that is not used in the combustion
process to the mass of air that is used in the combustion
process [4]. A higher bypass ratio means the engine is able
to achieve larger amounts of thrust from the fan itself,
simply when air is drawn in through the front and expelled
through the rear of the fan. Since more thrust is provided
from the fan, there is less of a need for the thrust that is
provided by the combustion of air in the propulsor.
Therefore, a higher bypass ratio results in less fuel
consumed and greater fuel efficiency. The GEnx turbofan
has a bypass ratio of almost 9.5 to 1, which is the highest of
any GE engine ever developed [5].
Key Words – Composites, General Electric Aviation,
General Electric Next-Generation (GEnx), Turbofan,
TURBOFANS, TRANSPORTATION FROM TOKYO TO
TORONTO
There is no denying that the invention of the jet engine has
revolutionized the way people travel. The jet engine allows
for faster air travel over significantly longer distances than
compared to older propeller driven aircraft. The first flight
of a jet engine, specifically a turbojet engine, powered
aircraft took place on May 15, 1941 [3]. Since that day,
many different classes of jet engines have evolved with each
designed for a specific purpose. One specific class of jet
engine is engineered specifically to be more efficient than
others, the turbofan jet engine. Turbofan jet engines are most
commonly equipped on commercial aircraft. Only recently,
with growing public concern for diminishing supply of fossil
fuels and global warming, have engineers been designing
these jet engines with an emphasis on fuel economy and fuel
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As previously stated, composites have a very high strength
to weight ratio. The weight of these composites will be
equally as beneficial to the fan blades and the engine.
Composite materials are less dense than metal alloys that are
more commonly found on other turbofan engines [6]. The
use of composites reduces the weight of the turbofans by
approximately 500 lbs [7].
When it comes to the fan blades it takes significant
amounts of energy to rotate those blades at the velocities
necessary for powerful thrust. The energy that gets those
blades rotating comes from the combustion of fuels, fuels
that cost money and emit harmful gasses into the air.
Composite’s lightweight characteristics drastically reduce
the total weight of the blades. Reduced blade weight makes
it easier to rotate the blades while decreasing the amount of
energy and fuel needed to do so. Further reducing the
amount of energy need is the composite materials ability to
be crafted into more aerodynamic shapes. The carbon fibers
that make up the composite blades can be intricately woven
so they are able to produce shapes that metals cannot. As a
result of more aerodynamic blades, the GEnx requires about
half the amount of blades as more conventional turbofan
engines [5]. It is ideal to have a more aerodynamic blade
because, when the blades rotate they cut through the air; air
resists this rotation through drag, thus decreasing the angular
velocity at which the blades can rotate. A blade that is less
aerodynamic will require more energy to reaching high
angular velocity. Since there is less drag on the aerodynamic
composite blades, they are able to rotate at greater angular
velocities compared to other turbofans while using the same
amount of energy. The reduction of number of blades along
with increased aerodynamic capabilities the GEnx greatly
increases its performance and efficiency.
Through the use of carbon fiber composites the fan blades
help to make some of the greatest leaps in modern turbofan
engineering. The incredible strength of the composites allow
for bigger and stronger fan blades that provide large amounts
of thrust, thrust that would otherwise derive from the
combustion in the propulsor. The reduction in the burning of
fuels, along with the structural and weight benefits of
composites create an economical and fuel-efficient engine.
THE BLADES
The blades are the most important component of the fan,
because the blades are virtually the only moving part of the
fan. The fan blades rotate at high angular velocities to take
in large masses of air. In order to take in large masses of air
it is ideal to design the blades to be as large and
aerodynamic as possible [5]. However, a larger and longer
blade means a heavier and weaker blade. The punishment
that these blades receive due to long flights and aerial debris
calls for a blade that is incredibly strong, yet lightweight. So
what makes the GEnx blades so revolutionary?
Composite Materials in the GEnx Fan
The GEnx blades were engineered to be bigger and stronger
through the use of composite materials. Composite materials
offer many advantages over traditional metal alloys, perhaps
most significantly is their strength to weight ratio;
composites can be engineered to be significantly stronger
than many metals while being far lighter [6]. The titanium
edged composite blades used in the GEnx fan are so strong
and durable, that during the first six million flight hours only
three blades have been removed from service [5]. The
strength of the composites used in the GEnx turbofan allows
blades to be made as large and lightweight as possible while
retaining reliability and durability. The benefits of composite
materials mean that the blades are virtually maintenance
free, thus reducing operational costs for airlines.
The entire operation of a turbofan relies on the movement
of air throughout the turbofan. The fan is the initial
component of the engine, if the fan does not function
properly, the rest of the engine will not function correctly as
a result. Composite fan blades ensure that the fan and the
propulsor always retain a steady airflow. The strength of the
composite materials allows for the construction of blades
with ideal aerodynamic designs for optimal performance.
For one, increasing the size of the blades is crucial to
provide for maximum air intake: each fan blade of the GEnx
turbofan is 55 inches long. These longer blades enable the
GEnx to achieve its remarkably high bypass ratio [5]. The
large fan blades are able to provide such a tremendous
amount of thrust that it greatly reduces the need for thrust
that is provided by the propulsor. Reducing the required
thrust from propulsor makes the GEnx more reliable by
relieving stress to the overall engine. This is because the fan
is mechanically simpler than the propulsor, thus reducing the
work done by the propulsor extends the life of the turbofan
due to the severity of the propulsor operating conditions.
The reliability of the fan blades drastically improves the
performance and efficiency of the engine as a whole. With
all of the current demands for cleaner and more efficient
engine, engineers at GE strove to make the GEnx as green as
possible. The GEnx is able to operate with such great
efficiency largely due to the use of composites.
THE FAN CASING
The fan casing is the housing for the fan and blades, and has
no moving parts. However, this does not mean that it doesn’t
contribute to the performance of the engine. The size of the
fan casing is an important contributing factor for producing
the large bypass ratio [8]. It is important for the casing to
also be very durable to protect the rest of the engine from
foreign object damage. The design of the casing is also able
to greatly reduce the sound produced by the engine. The
engineers at GE were able to achieve all of this and more by
applying the same techniques used for constructing the fan
blades.
Carbon fiber composites were used on the
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construction of the fan casing to make for a reliable and
lightweight housing for the fan blades.
The composites allow for the construction of a bigger fan
casing, which is key when trying to achieve a high bypass
ratio. While this is beneficial by providing more thrust it also
helps to greatly reduce the sound levels that are made by the
turbofan. The sound levels on the GEnx will be reduced by
13 decibels compared to its predecessor [5]. The reduced
level of sound makes for a comfortable cabin environment
for passengers, and ground crew working around the airport.
The larger size of the fan casing is also beneficiary to the
rest of the engine by directing debris that may enter the fan
away from the propulsor [5]. This ensures that the propulsor
receives a clean flow of air at all times. Carbon fiber
composites are also non-corrosive materials, meaning that
heat, weather or chemicals do not easily damage them [6].
This ensures that the casing remains strong and clean.
While the fan casing is a simple component it is still an
innovative component of the GEnx turbofan. The larger
casing allows for the larger fan blades used by the GEnx,
contributing to the high bypass ratio of the turbofan, and also
the reduction of sound from the engine. Additionally, the
resistance of composites to damage makes the composite
components of the GEnx far easier and cheaper to maintain.
The efficient, yet powerful GEnx high-pressure
compressor is the product of years of research in compressor
blade design along with a combination of technology used in
the GE90 turbofan. The compressor in the GEnx is
comprised of only ten stages, four stages fewer than the GE
CF6 engine it is replacing, however with technology in the
GEnx less is more, as the GEnx has “highest-pressure-ratio
compressor in the industry” with a 23:1 pressure ratio [9].
The pressure ratio of a compressor is a ratio of the air
pressure exiting the compressor to the pressure entering the
compressor. Higher pressure in general means higher
efficiency because gasses such as air get hotter at higher
pressures, thus providing more energy. The high-pressure
compressor of the GEnx is derived from the compressor of
the GE90 and the associated research General Electric did in
the construction and design of the GE90. The GE90 turbofan
was based on the NASA Energy Efficient Engine program, a
collaboration between General Electric and NASA to create
advanced energy-efficient turbofans [10]. Through the
acquired knowledge and research of the Energy Efficient
Engine program, General Electric was able to develop the
ten-stage, high-pressure ratio compressor of the GE90 and
the GEnx [11]. The pressure ratio of the compressor is
achieved by the design of the compressor airfoil blades.
With a focus of improving the aerodynamic design of the
blades, GE “introduced ‘blisks’ or bladed disks, with airfoils
that have been machined out of a solid piece of material or
have been joined to the disk [by] friction welding …
[increasing] strength and durability while [decreasing]
weight and aerodynamic loss” [12]. The blisks are
engineered so that virtually no air leaks out of the
compressor [12].
The design of the GEnx high-pressure compressor greatly
impacts the turbofan. The fewer stages (ten) in the
compressor allows for fewer moving parts in the
compressor, thus decreasing cost and weight of the turbofan.
The 23:1 pressure ratio of the high-pressure compressor
allows the GEnx to achieve improved fuel efficiency and
performance because higher pressures allow air to become
hotter thus increasing the potential energy and thrust of the
turbofan. The design of the high-pressure compressor stages,
and the blisks on three of the ten stages affect the GEnx
bypass ratio since essentially 100% of the primary airflow
passes through the compressor, thus allowing for an increase
in the efficiency of the turbofan.
CLEANER, SIMPLER, AND STRONGER; THE GENX
PROPULSOR
The propulsor is the next stage of the GEnx turbofan
following the fan. The propulsor is comprised of the
compressor, combustor, and turbine. Compressors compress
the primary airflow through consecutive stages causing the
pressure and temperature of the airflow to rise. This heated
air enters the combustor where it is mixed with fuel and
burned. The airflow flows through the turbines where its
pressure and temperature decrease, thus work is extracted;
allowing the two high-pressure and low-pressure turbines to
rotate and control respective high and low pressure systems.
General Electric engineers innovated each component,
utilizing technologies used in earlier turbofans such as the
GE90, and new technologies developed after years of
research. This collaboration of knowledge and technology
has led to the most advanced propulsor system currently in
use.
THE COMPRESSOR
THE COMBUSTOR
The initial stage of the core in aaå high-bypass turbofan such
as the GEnx is the compressor. The role of the compressor in
a turbofan is to compress the primary airflow (air which
flows into the engine core) through consecutive stages in the
high and low pressure compressors. The compressors of the
GEnx combines technology used in the GE90 along with
improved design and construction allowing the GEnx to
achieve the highest pressure-ratio for any turbofan.
The stage of the GEnx propulsor following the compressor is
the combustor. A combustor’s role in a turbofan is to mix
the heated, pressurized air from the compressor with fuel in
the combustion chamber and ignite it. The combustor of the
GEnx is the most revolutionary component of the turbofan.
It is the first turbofan to utilize a TAPS (twin-annularpremixing-swirl) combustor.
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After years of design, research and development, General
Electric was able to produce the TAPS combustor used by
the GEnx which allows the GEnx to be a lean and clean
machine. The TAPS combustor of the GEnx turbofan carries
the benefits of reduced nitrogen oxide emissions, and
achieves this by modifying the mixing process of fuel and
air in the combustion chamber, which will be discussed
further on. The TAPS combustor is the most innovative
feature of the GEnx turbofan, solving many emissions
problems associated with older turbofans.
and environmental acceptance of the national air
transportation system” [16]. One of the specific goals laid
out by NASA in the AST was “development of concepts for
reducing ozone-depleting nitrogen oxide emissions” [16].
Problems with NOx Emissions
Emissions of nitrogen oxides (NOx) are a problem
associated with most systems that rely on combustion to
operate. The effects of NOx can leave detrimental effects on
the environment and humans. The effect of NOx on humans
can be fatal if in a high dose, and can cause lung damage
over long periods of time [13]. With this information in
mind, it is clear as to why NOx emissions are subject to such
regulation, and why turbofan designers must focus on a
reduction of NOx emissions.
With the TAPS combustor in the GEnx, General Electric
wanted to moderate the emission of NOx. Generally, all
combustion engines produce NOx to some extent. Airliners
are not the world’s largest contributor of NOx, however
regulations have forced turbofans producers to comply with
regulation for NOx emissions at airports and during landing
and takeoff, however most of the NOx emissions produced
by aircraft occur during the cruise stage of flight [14].
Earlier turbofans focused on just adhering to these regulated
standards for takeoff and landing, but with GE’s TAPS
technology, NOx emissions are decreased not just during the
takeoff and landing stages of flight, but NOx is also
decreased during cruise aswell [14].
The TAPS combustor of the GEnx allows the GEnx to
adhere to current regulatory standards, however it also
provides another benefit for future regulations. If regulators
decide to place regulation on NOx emission for the cruise
stage of flight, there will not be a need for any modifications
to the combustor since it was already thought-out during the
design process of the combustor. This future-proofing of the
turbofan ensures that GEnx customers will not have to spend
money on engine modification in the future to adhere to new
regulation.
FIGURE 1
EVOLUTION OF COMBUSTOR TECHNOLOGY [15]
Figure 1 will be used to analyze the evolution of GE’s
combustor technology. As a result of NASA’s ACT
program, GE developed the double-annular combustor
which reduced NOx, however “the design has durability
issues, and is expensive and heavy” [8]. General Electric
then progressed to the TAPS combustor used in the GEnx
which brings improvements to design, and reduced NOx
production at all power ranges [14]. The knowledge gained
by engineers at General Electric when assessing the
problems in the DAC led to the development of the GEnx.
The combustor was developed to be lighter, and far more
efficient, and environmentally friendly than any of its
predecessors.
TAPS Combustor
To understand TAPS technology, it is important to first
understand how common single and double-annular
combustors used in turbofans today mix fuel and air, and the
effect of this on combustion.
TAPS Research
Twin annular premixing swirl technology is a revolutionary
combustion technology developed over a decade by GE to
combat NOx emissions [15]. The TAPS combustor grew out
of another collaboration of GE and NASA, the Advanced
Subsonic Technology program (AST). The aim of the AST
was to “[develop] high leverage technologies that [would]
assure the future competitiveness of U.S. civil transports,
and finding new ways to enhance the safety, productivity
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THE TURBINE
The final stage of a high-bypass turbofan is the turbine. The
turbine is composed to two stages, a high-pressure turbine,
and a low-pressure turbine, each powering respective high
and low-pressure components of the turbofan such as the
compressor and fan. The turbine extracts work from the
superheated and pressurized airflow exiting the combustor
by essentially reversing the role of the compressor. Airflow
enters the high-pressure turbine, and its pressure and
temperature decrease across the stages of the high-pressure
turbine. The airflow then flows to the low-pressure
compressor where the air is further de-pressurized and
cooled. The drops in the pressure of the primary airflow are
what allow the turbine to spin, and control low and highpressure components. The spinning of the high-pressure
turbine controls all upstream high-pressure components such
as the high-pressure compressor, while the spinning of the
low-pressure turbine controls the spinning of the fan and
low-pressure compressor. The high-pressure turbine, and the
low-pressure turbine operate on concentric shafts.
FIGURE 2
NOX PRODUCTION IN REGULAR COMBUSTOR VS TAPS [17]
Figure 2 provides an explanation to the production of NOx
emissions in a traditional combustor compared to a TAPS
combustor. In the process of mixing fuel with air in a
combustor, air passes through three chemical “points” as a
function of the distance from the fuel nozzle thus impacting
fuel/air ratio. Air must pass a rich stage, which is a stage
where there is excess fuel, air then peaks at the
stoichiometric NOx temperature, followed by a lean fuel air
mixture. In the case of an ordinary combustor, since air
chemically passed the NOx production zone, NOx was
obviously produced. Recent trends in turbofans have used
high-pressure compressors to reduce fuel burn, however
while this has a positive impact on the emission of carbon
dioxide, it has an inverse negative impact on NOx emissions
due to the higher temperatures associated with higherpressure compressors [14]. The problem with ordinary
combustors is how fuel and air are mixed. Fuel is mixed
with air in the combustion chamber, thus the burning occurs
at a higher temperature. In the case of the TAPS combustor,
General Electric’s solution was to premix fuel and air before
it ever enters the combustion chamber. The TAPS combustor
includes a computer-controlled system that measures the
temperature of the air entering the combustor, and then
mixes a specified amount of fuel with that air accordingly. In
the TAPS combustor, since air is already premixed with fuel
before ever entering the combustor, it doesn’t get the
opportunity to pass through the stoichiometric NOx
production zone, instead it ensures an always lean fuel-air
mixture. The fact that fuel and air are premixed also
provides a benefit of lower burning temperatures, thus
extending the life span of the combustor, and all downstream
components.
The GEnx TAPS combustor allows the GEnx to be a very
environmentally friendly turbofan. The GEnx alleviates the
problem associated with common modern turbofans in that
modern turbofans have achieved higher pressure ratios, thus
decreasing greenhouse gas production by increasing fuel
efficiency, however higher pressures have led to higher
burning temperatures, and thus increased NOx production.
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Stronger and Resistant Alloys
The turbine of the GEnx turbofan utilizes new alloys and
coatings, fewer parts, and a counter-rotating design of the
high-pressure and low-pressure turbines to make the turbine
innovative and revolutionary. The turbine is subject to the
rigorous conditions created by the combustor since it is the
next element downstream. Turbines have to be able to
withstand extreme heats, and continue operation for the
lifespan of the turbofan. To allow the turbine of the GEnx to
withstand the conditions imposed on it, engineers at General
Electric researched various alloys and coatings for the
turbine blades. The engineers discovered that by using
gamma titanium aluminide alloys “dramatic weight savings-up to 40 percent--can be achieved” [18]. In addition to the
weight benefits of gamma titanium alimunide alloys, the
alloys have shown to be structural strength, heat resistance,
and the ability to withstand a “relatively large impact
without failing catastrophically” [18]. With these benefits in
mind, GEnx engineers were the first to utilize gamma
titanium aluminides for the construction of the low-pressure
turbine blades. In addition to gamma titanium aluminides,
the GEnx turbine makes use of nickel aluminide in the
construction of the high-pressure turbine blades. Research
and data showed that the use of nickel aluminide as a
structural alloy was rather inefficient; therefore GE used
nickel aluminide as a coating for the blades of the highpressure compressor [18]. Additionally, the nickel aluminide
increases high-pressure turbine “hot corrosion resistance by
50 percent” [19]. The use of gamma titanium alumides and
nickel aluminide in the design of the GEnx turbofan gives
the turbofan structural, weight, and longevity benefits. The
alloys and coatings used in the GEnx allow the turbofan to
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provide twice the cyclic life compared to the GE CF6
turbofan it is intended to replace [5]. Since the brunt of
turbofan maintenance costs for airlines come from turbine
maintenance, the effect of the alloys used in the
development of the GEnx turbofan will reduce maintenance
and operational costs for airlines.
decrease in the cost of maintenance of the turbofan and
aircraft by reducing the stress on both components.
AIRLINE AND INDUSTRY IMPACT
There is a greater public realization in today’s society of the
effects of human machines on the environment. There is a
demand to make engines environmentally friendly. In
addition, the current state of the global economy means that
machines, specifically engines, must become efficient in
order save money. The GEnx was built with the goal to
become the most economical and efficient engine on the
market. General Electric engineers analyzed every single
component of the turbofan to look for ways to reduce
materials used, and find ways to improve fuel efficiency.
The GEnx, which will be used on the 787, A350, and 747-8
fleets of airlines, will deliver a “15 percent better specific
fuel consumption.” [2]. Last year, domestic U.S. airlines
spent a total of about thirty-one billion dollars on fuel alone
[Transtats]. With airlines spending large amounts of money
on fuel, a fifteen percent decrease fuel consumption would
alleviate airline fuel costs. Customers ultimately benefit
from this fuel efficiency. By cutting the costs spent on fuel
the airline industry will be able to make their tickets more
affordable, attracting more customers. Another problem that
impacts airline business is the public views on the emissions
caused by aircraft. The GEnx, with its innovative TAPS
combustor, improves on emission reduction. Fuel savings,
and emission reduction makes the GEnx an attractive option
for many airlines.
Turbine Blades
General Electric put great emphasis on the aerodynamic and
operational design of the GEnx turbines. GE engineers
focused on reducing weight, while also optimizing
geometric and functional components of the turbofan. The
GEnx turbine blades are constructed in a 3D Aero design
pattern. The 3D Aero design of the turbine blades means that
the blades of the turbines are presented to the air at an
optimum angle in relation to the length of the blade [5]. This
design improves the efficiency of the turbofan by optimizing
the turbine blades in such a way to reduce drag on them
from the primary airflow through the turbines. Additionally
since the design of the blades is optimized for efficient
airflow, fewer blades can be used on the turbines. The
number of blades on the first stage of the low-pressure
turbine is reduced by 15% and the number of blades on the
second stage of the high-pressure turbine is reduced by 10%
[15]. Fewer blades on the turbines allow reduction in weight
and cost of the turbofan, thus further increasing efficiency.
Counter-Rotating Design
The third main design element of the GEnx turbines is their
counter-rotating design. The low-pressure turbine spins
counter clockwise in relation to the high-pressure turbine,
whereas on common turbofans, both the high-pressure and
low-pressure turbines spin uniformly clockwise. This
counter-rotating provides the benefits of the turbofan having
fewer parts, leading to less weight, and improved efficiency
[5]. When an airmass flows over a rotating blade such as the
turbine, some of the airmass flows through the blades, while
other bits of the airmass are spun around creating a
rotational or tangential flow to the turbine blades. The
energy associated with the rotational air flow is lost with
uniformly rotating turbines. Additionally, the asymmetric
torque creates stress on the entire turbofan assembly and the
engine mounts on the wing of the aircraft. With a counterrotating turbine design, the turbine utilizes the airmass that
flows tangentially; this means that the turbines utilize nearly
all of the energy. In addition to the energy benefits, the
counter-rotating would ideally create a system with no net
torque, thus stress on the entire turbofan and engine mounts
on the wing is reduced. The counter-rotating design of the
GEnx turbines therefore provides economic benefit for
airlines. Little energy is lost, thus fuel efficiency is
increased, and operational costs are decreased. The structural
impact of the counter-rotating design also produces a
THE ENGINE OF INNOVATION
The advancements and innovation that GE implemented into
the GEnx turbofan makes it one of a kind. GE implemented
many new technologies and ideas into the design and
function of the turbofan, all done to make the GEnx an
economical and efficient option for both the environment
and the airline industry. The fan of the GEnx utilizes
innovative composite materials which allows the GEnx
turbofan to achieve the highest bypass ratio of any GE
turbofan, while also providing significant weight reduction.
In addition to the fan, GE added new technologies and ideas
to the turbofan propulsor. Each component of the propulsor
was designed/re-designed to increase efficiency while
simultaneously providing optimal power. The resulting
turbofan of all this innovation, the GEnx, is truly an engine
of innovation.
REFERENCES
[1] J. L. Lawrence. (2000, July). “The mechanics of flight”. Mechanical
Engineering Magazine. [Online]. Available:
http://www.memagazine.org/backissues/membersonly/july00/features/mech
flight/mechflight.html
[2] “GEnx Engine Family.” GE Aviation. [Online]. Available:
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Yevgeniy Riftin
Sean Hart
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our conference chair, James Hayes, and our conference cochair, Matt Goodwill for all of their help and their
constructive criticism with regard to our paper.
ACKNOWLEDGEMENTS
We would like to thank Beth Newborg with all of her help in
the initial stages of our paper. We would also like to thank
University of Pittsburgh
Eleventh Annual Freshman Conference
Swanson School of Engineering
April 9, 2011
7
Yevgeniy Riftin
Sean Hart
University of Pittsburgh
Eleventh Annual Freshman Conference
Swanson School of Engineering
April 9, 2011
8