1) The document provides a history of the development of gas turbine engines from early concepts like Hero of Alexandria's aeolipile in the 1st century to modern trends. 2) Key developments included Frank Whittle's patent for a gas turbine engine in 1930 and the first flight of a jet-powered aircraft by Germany in 1939. 3) Modern gas turbine engines are classified based on their compressor type and power usage, including turbojet, turbofan, turboprop, and turboshaft engines used in aviation and other industries.

1. General Sir John Kotelawala Defence University, Sri Lanka
Faculty of Engineering
Department of Aeronautical Engineering
History, development and
modern trends in gas turbine
Engines
Name of the Lecturer: Mrs. JI Abeygoonawardena
Name of Student: Sushil Khadka
Stream/Intake: AE/34
Subject: Air Breathing Propulsion II
Date of Submission: 23rd July 2019

2. 1
“History, development and modern trends in gas turbine Engines”
Introduction to gas turbine engines
Quest for speed and reach was unravelling new and optimized design of airplanes in the two decades
following the invention of airplane. World war II was fueling up the European leaders with the zeal of
having air superiority in adversary’s domain. Germany and England were the pioneering countries in
advancing the capabilities of aircraft. With this continuous battle for dominance in air power,
manufacturing of aircrafts was taking a steep progress with new discoveries in ways for enhancing
aerodynamics of the airplane. As every components and systems were getting upgraded, some radical
change in propulsion system became a necessity to meet the requirements of evolving aviation industry.
In different cradles of great minds within Europe, the race to develop a new type of engine was already
on. Germany and England independently designed, patented and tested their own versions of this new
engine while engineers in Italy and other European countries were also contributing with their intellect in
their national aircraft manufacturing companies. This new type of engine was called as gas turbine engine,
to which we casually call as jet engine. Earliest versions of these engine worked much like a rocket engine
creating hot burnt gases which were ejected through a nozzle producing thrust. But the differences were,
rocket engine needed separate oxygen supply to burn the fuel while gas turbine engine used oxygen from
the atmosphere. So, for a gas turbine engine, the working fluid is jet exhaust most of which is composed
of surrounding atmospheric air. Now, most of the modern aircrafts, either military or commercial, uses
gas turbine engine for propulsion. Simply, Gas Turbine engine is an air breathing continuous combustion
internal combustion engine that operates in Brayton cycle.
Figure 1 Gas Turbine Engine
To simplify the history of development of gas turbine engines, we can categorize the progress into three
different intervals; before the invention of actual gas turbine engine, invention and development of gas
turbine engine and modern trends and future concepts for gas turbine engine.

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Early works before Invention
In the first century, Hero of Alexandria converted the flow of air to usable rotary motion in his windwheel.
He is also credited for making Aeolipile which used the basic concept of modern day jet engines. The water
in the container was heated which exited through the jet nozzles thus called as bladeless radial steam
turbines.
Figure 2 Aeolipile
Leonardo Da Vinci in 16th
century sketched the smoke jack, the hot gases moving up the chamber could
strike the bladed vanes in the top that was mechanically linked with a shaft and pulley to lift objects. This
was later described in detail by English clergyman John Wilkins in 1628. As this mechanism was used to
roast the meat, it was also called roasting pit.
Figure 3 Da Vinci's smoke jack
In 1629, Giovanni Branca, an Italian engineer invented stamping mill which used steam to rotate the
turbine that was connected to a mill through gearing. It was the first impulse turbine in the history.
Ferdinand Verbiest made a trolley for Chinese emperor in 1678. It used a bowel of water which was heated
to create steam and passed through a small nozzle to rotate a turbine connected to the wheels of trolley.
Later in 1687, Sir Issac Newton had formulated the laws of motion. A Dutchman, Jacob Gravesand

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designed a horseless carriage or Newton’s wagon based on the laws of motion. It is thought that the idea
for this design was also given by Newton. It consisted of a large boiler contained within four wheels, which
ejected the boiled steam to move the wagon.
Different types of reaction turbine drives were invented in 19th
century. Most of them used externally
compressed air by reciprocating compressors to drive the rotary saws, drills and other devices. Although,
this cannot be compared with the gas turbine engines as it should consist of distinct compressors,
combustion and turbine components which is contained within itself. The first approximated engine of
such type was proposed by Englishman John Barber in 1791. He was issued the patent to the engine whose
sketch included a fuel fired combustion chamber that got compressed air from an external reciprocating
compressor. The hot air jet was passed through the nozzles to an impulse wheel that produced sufficient
energy to drive the chain driven reciprocating compressors and the output load. It was supposed to be
used in the “horseless carriage” but the inefficiency in the output and lack of suitable materials prevented
it from getting produced.
Figure 6 John barber's gas turbine patent
Figure 3 Stamping Mill
Figure 4 Stamping Mill Figure 5 Newton's wagon

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Another significant advance in turbine engines was achieved in 1872 as a patent was granted to a German
inventor Franz Stolze. His design consisted of multistage, axial flow compressor and a reaction turbine
mounted on the same shaft. The compressed air was passed through separate combustion chamber
where it was heated by the exhaust from the turbine. The hot compressed gases were passed to the
turbine for mechanical work. Although this design featured almost every feature of modern day gas
turbine engines, turbine and compressor lacked efficiency to sustain operation in low turbine inlet
temperature feasible at that time.
Figure 7 Franz Stolze's patent on gas turbine engine
In 1884, sir Charles Parson took many patents on gas turbine concepts. He was also the first person to use
the concept of turbine to propel the boats. ‘Turbinia’ was the first steam powered turbine ship and the
fastest water vessel to cruise in the ocean in 1893. In 1899, radial flow generators made by parson was
installed in Cambridge, England generating 100KW electricity. It was the first attempt to use turbines to
generate electricity stationed in land. Similarly, Dr Sanford A. Moss developed the turbosupercharger. The
original idea for turbosupercharger was brought up by Rateau of France which was very similar to a jet
engine in working mechanism. The only lacking component in this design was the combustion chamber.
Egidius Elling made the first gas turbine that was capable of producing more power than it was required
to keep its own components running. It was the very year 1903 in which Wright brothers flew their
airplane marking a landmark in history. Since the fundamentals on aerodynamics were still building up,
Elling’s compressors and turbines were very inefficient and produced only 11 hp. Dr A. A. Griffith
revolutionized the development of gas turbine by giving a theory of designing turbine based on flow of
exhaust gases past airfoil, which was in contrary to the contemporary passages.
Figure 8 Charles Parson's first steam turbine

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Invention and Development of gas turbine engines
The final milestone in development of gas turbine engine was marked by sir Frank Whittle. He joined the
Royal Air Force(R.A.F.) as a young air cadet. He submitted a thesis which proposed the use of gas turbine
engine for jet propulsion. Eighteen months later, this idea was seriously taken and he began sketching
designs for this concept. In 1930, his conceptual work on the use of gas turbine engine as jet propulsion
had reached to the stage where he applied for the patent on the same concept. There were ideas for the
ramjet in his patent that did not get approved, as it had already been proposed previously. In the
succeeding years until 1935, there was no significant development on practical and working gas turbine
engine. Also, it was turned down by the British Air Ministry and several manufacturing firms because they
did not believe that it could be practical to use in the flight. In 1935, two former Royal Air Force officers,
Williams and Tinling found Whittle at Cambridge where they suggested him to apply for several patents
so that they could raise money for developing their prototype on gas turbine engine. So, in March 1936,
Power jet Ltd. Was formed with the help of a banking firm. In Britain, the first experimental flight came in
1945.
German developments
Meanwhile in Germany, Lufthansa was experimenting with new forms of propulsion. ME-262 had new
type of propulsion and revolutionary features like swept wings and no tail which were designed solely for
the speed. There was no landing gear which required a detachable wheel for takeoff at runway. Also, the
fuel consisted of hydrogen peroxide, methyl alcohol, hydrogen hydrate and water. Pilots were unsafe
from this volatile fuel. It consisted of a rocket engine which was powerful and generated an enormous
thrust of about 6000 horsepower. With the ongoing pressure of the war, German scientists were eager to
make planes capable of vertical takeoff. The eminent risks of crash landings made Germans to develop jet
engine. With the supportive coordination of German air ministry, Ernst Hienkel aircraft company adapted
Hans von Ohain and Max Hahn’s patent on jet engine and developed the first jet engine to be fitted in the
plane. The first flight on that aircraft was made by pilot Erich Wahrsitz on 27th
august 1939. This is now
considered as the first modern jet propulsion to be tested. The HE178 was propelled with a jet engine and
Figure 10 First British jet engine W2/700 Figure 9 First British jet powered airplane Gloster
E.28/39

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it was named after Heinkel, the creator. This used a centrifugal compressor developing 4893 Newtons of
thrust flying the aircraft at 644 km/hour. Further development of ME-262 consisted of two axial-flow jet
engines. This aircraft went for mass production but came too late to create any difference in the final
stages of world war II. Many of modern day jet engine features like ice prevention, blade cooling and
adjustable exhaust nozzle were incorporated in these designs. These astounding works of Whittle and von
ohain were recognized and they were honored as the co-inventors of jet engines in 1991.
Figure 11 First aircraft to fly on turbojet -He 178
Contribution by Italy
In August 1940, Secundo Campini developed a reaction engine in Caproni company and made the first
successful flight. It was not peculiarly a jet engine but used a reaction mechanism to propel the aircraft.
The engine consisted of three stage compressors driven by reciprocating engine. The top speed attained
by this aircraft was 330 km/h and the project was disbanded later in 1948.
Figure 12 World's second aircraft to fly with jet engine - Caproni Campini N.1

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Development in America
Development of gas turbine engine in America took pace in the later part of the decade. W.1X and W.2B
gas turbine engines were flown in September 1941 under collaboration of British and United states
government which was guided by NASA(National Aeronautics and Space Administration) which used to
be called as NACA(National Advisory Committee for Aeronautics) back then. The test was done in the
United States ground. General Electric Corporation used to be the leading company in manufacturing
turbosuperchargers. So the contract to build an American version of jet engine was given to it with the
supervision of power jet engineers sent from Britain.
Bell XP-59A became the first aircraft to be flown in United States in October 1942. Piloted by Robert M.
Stanley, this aircraft was powered by two General Electric I-A engines and rave 5782N of thrust. This
experimental aircraft used the Whittle design with modifications. This was marked as a great achievement
because these engines were manufactured in a year and had lower specific fuel consumption with 1334N
extra thrust than Whittle engine. This gave General Electric successful entry into the race of manufacturing
gas turbines. Westinghouse Corporation, which used to produce steam turbines, got chosen to build all
American designed gas turbine engine by NACA. So, engineers in Westinghouse designed an axial
compressor engine with annular combustion chamber which has been proven to be a good development
and used popularly in modern engines.
Developments of gas turbine engines in other industries
Apart from these development of gas turbine engines aimed to be used in aviation, other field of science
were also advancing in development of gas turbine engines. Increasing population and necessity for more
energy in factories promoted alternatives for power generation. Land based generation was increasing
and industrial gas turbine engines immediately took the market. Apart from direct power generation and
propulsion in aviation, use of gas turbine engine flourished in marine propulsion, blast furnace blowers,
road vehicle engines, mechanical drives and locomotive engines. Experimenters continuously kept on
testing the viability of gas turbine engine in variety of applications. This interest in application of gas
turbine engine on wide scope of engineering promoted the further development and modification of gas
turbine engines for better output and efficiency in respective required field of application.
Figure 14 Power Jets W.1 engine
used to fly Bell XP-59A
Figure 13 Bell XP-59A

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Modern Trends
The breaking of sound barrier in 1947 by Chuck Yeager in rocket propelled Bell X-1 unlocked a new horizon
for high speed flights. Since then, it became a prime objective of aircraft manufacturers to break this
barrier using gas turbine engines. The engines were redesigned and modified to fly the aircraft faster than
the speed of sound. Ultimately, in 1953, American YF 100, designed by Pratt and Whitney became the first
jet engine to break this wall of sound resistance. Almost after thirty years of this historical event, Concorde
became the first supersonic aircraft to carry passenger in 1976. This was a joint brilliancy of Britain and
France. But the economic failure and disastrous crash in 2000 led the grounding of this aviation marvel.
Nowadays, gas turbine engines are manufactured in wide variety of arrangements. But the basic
classification can be done based on the compressor type and power usage. The historical trend for the
development of gas turbine engines under these divisions is discussed below.
Classification of gas turbine engine based on power usage:
 Turbojet
 Turbofan
 Turboprop
 Turboshaft
Turbojet
It is the first and simplest type of gas turbine engine. Turbojet engines continuously sucks large amount
of air form the surrounding through inlet. In England, it was first termed as inlet, which was an accurate
definition because the next component, compressor pulls the air into the engine. A compressor is like
many row of airfoils in which every row produces small jump of pressure. Air exiting from compressor is
high pressure which is injected with fuel and ignited in the burner or combustion chamber. Hot exhaust
leaving the combustion chamber is passed through turbine which works like a windmill. It extracts part of
the energy from hot exhausts by transforming it into a rotatory motion. Turbine is linked to compressor
by single shaft and rotates the compressor. The flow exiting from the turbine is at high temperature and
pressure which is passed through the nozzle to accelerate the flow. Since the exit velocity is greater than
the free stream airflow velocity, a net thrust is created. This is the basic working principle for turbojets.
The history of turbojets is as much as the history of gas turbine since turbojets were the first type of gas
turbine engine. Heinkel He 178 was the first aircraft to be flown using turbojet engine in 1939. Germans
pioneered the development of aircraft using turbojets before any other countries. But the lack of the
durability of material in high temperature led them to stand slow in the development of turbojet aircrafts.
Meanwhile, British were advancing by using durable materials like that in Rolls-Royce Welland which ahd
comparatively longer flight hours possible. More than England, united states was already in good position
to manufacture turbojets since they had good experience with high temperature materials used in
turbosuperchargers made by General Electric. The last commercial aircraft to use turbojet was Concorde
which used Olympus 593 engine.

10. 9
Figure 15 Turbojet Engine
Turbofan
Most modern commercial airliners use turbofan for the propulsion. It consists of a core gas turbine engine
and a fan in the front with additional turbine to drive it at the rear. The fan is composed of many blades
like that of the core compressor. A two spool arrangement is used to separately connect fan with power
turbine and compressor with core turbine. This engine is modified and rearranged in many possible ways
for enhanced efficiency. In this engine, the some of the incoming air is passed through compressor unit
while the rest is bypassed through the duct. It’s efficiency lies between the turboprop and the turbojet.
Figure 16 Turbofan Engine
The first turbofan engine to be tested was Daimler-Benz DB 007 built in 1943 by Germans. Howerver, Pratt
& Whitney JT3C and Bristol Olympus were the first efficient and implementable turbofan engines. Further
development in metallurgy and manufacturing processes have made designing of high bypass and
complex turbofan enginies possible.

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Turboprop and Turboshaft
Suitable for most of the low speed small transport aircraft, turboprop engine is popular for short
destination aircrafts. It used a gas turbine at its core to drive a propeller. These propellers move large
mass of air through it by adding small velocity to develop thrust. There are two main parts in turboprop
propulsion, the propeller and the core engine. The core is similar to the turbojet having intake,
compressor, combustion chamber and a turbine with an extra turbine at the exit to rotate the propeller.
Turboshaft is a variation of turboprop engine. The turbine is connected to a shaft to drive other
components through gear box in turboshafts. Its usage is seen in helicopters, tanks and ships and also
race cars in 1960’s. Mechanical engineer György Jendrassik, fromhungary was the first person to design
turboprop in 1928. But the mass production of this engine took pace in 1942 following the design by Max
Adolf Mueller from Germany. Many concepts and designs were tested for turboprop throughout the
history and it proved to be sufficiently reliable and efficient with only problem of limitation in maximum
speed and ceiling. Today, ATR 42/72, Bombardier Q400 and Dash 8, Beechcraft 1900, de Havilland Canada
DHC-6 Twin Otter and Saab 340 are among the aircrafts produced that use highest number of turboprop
engines.
Figure 17 Turboshaft engine

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The recent advancement in turbofan engine is focused in creating more silent and fuel efficient engines.
Established manufacturers have invested a lot of resources and manpower to bring design and production
line together, so that the product requirement is met by optimizing in the time of need. Engineers have
found creative solutions to these problems. For example, the intake of air in the fan should not exceed
the sonic speed to maintain the efficiency of fans. But, compressors and fans are connected in a single
spool which results the same RPM of fan and cause high velocity of incoming air through the fan blades.
So, gearing mechanism is used to rotate the compressor and fan at different speeds. This enables ultra-
high bypass ratio turbofans with increased propulsive efficiency. Some of the modern turbofan engines
like used by Boeing 737 max consists of serrated nozzle at the exhaust to reduce exhaust noise by
suppressing the turbulent mixing of exhaust air.
Thrust reversers in gas turbine engines are bulky and need extra mechanisms to be fully deployed.
Conventional thrust reversers in propeller engines uses the pitching mechanism of propeller to reverse
the thrust during landing. Adapting this way into gas turbine engines by introducing variable pitch fan
blades can reverse the thrust during landing for braking at lower manufacturing weight. Also, viability of
using variable geometry compressors with optimized blade design to expand the operational flexibility of
compressors are being tested. Improved performance is expected by using this configuration.
Advanced and sophisticated electronic engine controls has lowered specific fuel consumption to a great
extent. Also, efficient turbines will result fewer stages for required work output and lighter engines with
lesser cooling requirements. Development in metal alloys with ceramic coatings and its use in turbine
blades has made high temperature for turbines possible. Improvement in combustion chamber has
facilitated burning of fuel more cleanly and efficiently so that the engine is more environmental friendly.
Proper maintenance is a must to keep the engine in proper condition for long lasting service. Engine
monitoring and testing equipment are developed to analyze the status of engine. Further, vibration
detectors, oil analyzers and sensors to measure temperature of turbine blades are to be installed in future
aircrafts engines. With the borescope capability and radiographic techniques, the basic parameters of the
engine can be monitored. New manufacturing techniques have been discovered which uses diffusion
bonding and complicated welding methods which helps in maintenance and repair of engine components.
Figure 18 Thrust Vectoring

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Thrust vectoring is a trending concept in modern fighter aircrafts. It is used to improve the row pitch and
yaw control authority of the aircraft. Maneuverability thrust vectoring was first tested in 1987 in FA-18
hornet. Thrust vectored control can keep the aircraft stable at extreme angles of attack. Lockheed Martin
incorporated this technology in F22 raptor for the first time. But, it was Russians to use three dimensional
thrust vectoring firstly in AC-37 by adding directional forces from the exhaust gas of the engine to the
pitch, roll and yaw axis of the aircraft. It was achieved by using the special nozzles at the rear of the
engines. Presently, they are capable of directing the air vertically and laterally up to 220
. And this
phenomenon is done solely by the engine. Space shuttles used this technology long time ago. But the
aircraft incorporated it with the recent development of gas turbine engines. In addition, many modern
fighter planes use low bypass ratio turbofans equipped with afterburners. It increases the cruising
efficiency while having high thrust when dogfighting.
Financially, the production of gas turbine engine is a huge success. That is one of the key factor for
manufacturers and government to continuously push for the development of more and more efficient
engines. The platinum Forecast system researched and concluded that total of $508 billion has been used
in the trade of gas turbine engines[1]. Out of which, turbofan engine is the most demanded engine in
aviation market as shown by the pie chart in figure 20.
Source:
The
Platinum
Forecast
System®
Figure 19 Trend in Aviation gas turbines economics

14. 13
Source:
The
Platinum
Forecast
System®
Figure 20 Market share of Gas turbines engine types in Aviation industry

15. 14
References
[1] [Online]. Available: https://dsm.forecastinternational.com/wordpress/2016/07/25/the-world-
aviation-gas-turbine-market-2016-2030/. [Accessed 18 07 2019].
[2] Britannica. [Online]. Available: https://www.britannica.com/technology/gas-turbine-engine.
[Accessed 12 07 2019].
[3] B. MacIsaac and R. Langton, Gas Turbine Propulsion Systems. Hoboken, UNITED KINGDOM: John Wiley
& Sons, Incorporated, 2011.
[4] I. E. Treager, Aircraft gas turbine engine technology, 3rd ed. New York, N.Y: Glencoe, 1996.