Gas Turbine Engine Flashcards
History of Jet Propulsion, Jet Engines Basic Operation, Types of Jet Propulsion, Types of Gas Turbine Engine
a writer and mathematician named
___________ devised a toy that used the
______________. The toy, called
the ____________, consisted of a
covered kettle of water that was
heated to produce steam.
WHAT YEAR?
Hero, reaction principle , aeolipile, 250 BC
The first patent covering a gas
turbine was granted to ____________
of England. It included all the
essential elements of the modern
gas turbine except that it had a
reciprocating-type compressor.
WHAT YEAR?
John Barber. 1791
______________ applied some of
his concepts in the development of
the ________________. This unique
supercharger consisted of a small
turbine wheel that was driven by
exhaust gases. The turbine was then
used to drive a supercharger
WHAT YEAR?
Dr. Sanford Moss, turbo-supercharger, 1900
________________ of England
developed what became the
first successful turbojet
engine and was granted his
______________-
WHAT YEAR?
Frank Whittle, first patent for the jet engine, 1930
_______________, a German
engineer, designed and built a
jet engine that produced ____________ of thrust.
WHAT YEAR?
Hans Von Ohain, 1,100
pounds, 1936
Hans’ engine was installed in the _______________ aircraft in ____________. it became recognized as the _______________ by a jet propelled aircraft.
WHAT YEAR?
Heinkel He-178, first practical flight, 1939
Frank Whittle’s engine
completed its first flight in a
_______________ aircraft.
The engine produced about _____________ of thrust and propelled the aircraft at speeds over _________________.
WHAT YEAR?
Gloster model E28/39, one thousand lb, 400 miles per hour, 1941
Another step in the progression of
commercial and military aviation was
the ability to produce an engine that
would propel an aircraft faster than
the speed of sound. Such aircraft are
the _____________ which flies in
excess of _________ and the
____________ capable of flying ____________
the speed of sound.
SR-71 Blackbird, Mach five, Concorde, 2.2 times
Newton’s First Law
A body in motion remains in motion, a body at rest remains at rest, unless acted upon by a force.
Newton’s 2nd Law
F=m*a
Newton’s Third Lan
For every action, there is an equal and opposite reaction
The main function of any airplane propulsion system is to provide a force to
overcome the aircraft drag,this force is called ____________-
thrust
When a jet engine accelerates air (mass), it makes _____________.
thrust (force)
Jet engine thrust can be increased in two ways:
Increase the speed of exhaust gases.
Increase the quantity of exhaust gases.
Basic Operation of a Jet Engine
AIR ENTERS THROUGH THE INLET DUCT (COWL).
AIR COMPRESSED BY PASSAGE THROUGH THE COMPRESSOR.
MIXED WITH FUEL IN THE COMBUSTION
CHAMBER.
FUEL IS IGNITED, PRESSURE AND TEMPERATURE RAISED
SOME OF THE PRESSURE USED TO TURN A TURBINE;
TURBINE SHAFT DRIVES THE COMPRESSOR.
HOT, HIGH PRESSURE AIR FORCED THROUGH A NOZZLE.
THE REACTION FORCE IS THE ENGINE THRUST.
Propulsion Devices
Air-Breathing
Non Air-Breathing
Air-Breathing :
Reciprocating Engines
GasTurbine Engine
Ramjet Engine
Non Air-Breathing:
Rockets
Types of Jet Engines
ramjet
pulse jet
scram jet
rocket
gas turbine engine
athodyd(or aero-thermodynamicduct), an air-breathing engine with no moving parts
Ramjet
Ramjet
With no rotating compressor to draw air into the engine, a ramjet must be
_____________- before it can produce thrust.
moving forward at high velocity
similar to ramjets except that the air intake duct is equipped with a series of
shutter valves that are spring-loaded to the open position.
Pulse Jet
A pulsejet is typically considered more useful than a ramjet because pulse jets can ________________.
produce thrust prior to achieving a high forward speed.
SCRAM Jet vs. Ramjet
a ramjet decelerates the air to subsonic
velocities before combustion,the airflow in a scramjet is supersonic throughout
the entire engine.
A _______________ is a variant of a ramjet air breathing jet engine in which combustion takes place in supersonic airflow.
scramjet (supersonic combustion ramjet)
A ___________ is a non-air-breathing engine that carries its own fuel and the oxygen needed for the fuel to burn
rocket
The two types of rockets in use:
solid-propellant rockets
liquid-propellant rockets
used primarily to propel some
military weapons and occasionally to provide additional thrust
fortakeoff of heavily loaded aircraft.
solid-propellant rockets
The _____________ and oxidizer
are carried in tanks aboard the rocket.
liquid propellant rockets
The __________ is the most
practical form of jet engine in use
today.
gas turbine engine
gas turbine engine
Use ___________ to power
a propeller or produce direct thrust by
____________________
high-temperature gases
expanding and accelerating the exhaust gases through a nozzle
Types of GTE
Turbojet
Turboprop
Turboshaft
Turbofan
The difference in velocity in the inlet and exit produces thrust.
Turbojet
which is the ratio of turbine discharge pressure to the inlet air pressure
engine pressure ratio
____________ engines are similar in design to turbojet engines except that the
power produced by a ____________ engine is delivered to a _____________ that spins a propeller.
Turboprop, reduction gear
system
______________ is necessary in turboprop engines because optimum
propeller performance is achieved at much slower speeds than the engine’s
operating rpm.
Reduction gearing
The output of a turboprop or turboshaft engine is measured by __________
rather than thrust.
shaft horsepower
Turboshaft vs Turboprop
The main difference between the two variants is that a TP engine might also
produce a fraction of its overall thrust via a hot core exhaust jet, while a
conventional TS engine will have a lower exhaust velocity but correspondingly
somewhat higher shaft power as the tradeoff
___________ were developed to provide a compromise between the best
features ofthe turbojet and the turboprop.
Turbofans
Turbofan
Nearly all present day airliners are powered by turbofan engines forthese
reasons as well as because turbofans are _____________________
relatively fuel-efficient
Turbofans are likeTurbojets but also have a large fan accelerating the
air’s entry into the engine and adding to the thrust as an ________________.
internal propeller
Inlet air passing through a turbofan engine is usually divided into two separate streams of air
One stream passes through the engine core
Second stream coaxially bypasses the engine core
One stream passes through the engine core, and…..
i. Fuel and air is burned in the combustion chamber,
ii. Air expands and spins the turbine which in turn drives the compressor. (self-sustaining)
iii. Air leaves the exhaust at high velocities which produces thrust.
Second stream coaxially bypasses the engine core. and….
i. Air is accelerated through the bypass engine which contributes a significant amount ofthrust.
ii. Aside from thatit also helps cooling the engine.
From this bypass stream of air, this powerplant is referred to as a ____________
bypass engine
a comparison ofthe thrust produced by the fan to the thrust produced by the engine core exhaust
Thrust ratio
refers to the ratio ofincoming airthat bypasses the core to
the amount of airthat passes through the engine core.
Bypass ratio
Bypass ratios
low bypass (1:1)
medium bypass (2:1 or3:1)
high bypass (4:1 or greater)
_____________ determines a fan ‘s bypass ratio and thrustratio.
Fan diameter
ratio of air pressure leaving the fan to the air pressure entering the fan
Fan pressure ratio
The fan pressure ratio on a typical low bypass fan is approximately __________, Whereas the fan pressure ratio for somehigh bypass fans
can be as high as _____________
1.5:1
7:1
Types Of PropFan
Unducted FanEngines
Ducted Ultra High Bypass Engines
New engine designs with higher efficiencies than most engines in use are designated as ___________ and ____________
ultra-high bypass (UHB) propfan and unducted fan (UDF) engines.
Prop Fan
These new engines use ___________, __________, and _____________ to improve fuel economy over several high bypass turbofan engines by more than _______
percent.
titanium, lightweight stainless steel, composite materials
15 percent
PropFan
By incorporating propellers with composite blades between 12and 15 feet in diameter, engine designers have achieved __________ bypass
ratios.
30:1
Another design encases the propfan in a
conventional cowl-type inlet which can
achieve _________ .These engines are known as _______________.
Mach 0.9
ducted ultra high bypass engines
Disassembly of A Gas Turbine Engine
Disassembly
Cleaning
Inspection
Repairs
Balancing
Assembling
Testing
