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Turbine Engines

What are the three major functioning sections of the turbine engine? Compressor, combustion, and turbine
Turbofan engines are categorized as: High and low bypass
The two functional elements of a centrifugal-flow compressor are: Impeller and diffuser
What section is located between the compressor and turbine sections? Combustion
Name the principal types of compressors centrifugal and axial
What constitutes a stage of compression in an axial flow compressor? Rotor and stator
What does VIGV stand for? Variable Inlet Guide Vanes
What are the three basic types of combustion chambers? can, annular, and can-annular
What is the primary purpose of the turbine section? Turn the compressor
What is the primary purpose of the combustion section? Provide a place for the fuel/air to mix and burn
How are turbines blades attached to the turbine wheel? Fir tree attachment
What type of bearings are used in the turbine engine? ball and roller
How many igniters are normally in an aircraft turbine engine? 2
How are engine stresses transferred to the aircraft structure? Engine mounts
What prevents oil from leaking past a labyrinth seal? Positive air pressure
The Brayton cycle is known as what? The constant pressure cycle
Where is the highest gas pressure in a gas turbine engine? The entrance of the burner section
Where is the highest gas temperature in a gas turbine engine? Inlet of the turbine
What type of ignition source is typically used in gas turbine engines? High-energy capacitor discharge
What occurs at high altitude where low engine speeds and low fuel pressure form a weak flame that is extinguished in a normal airflow? A lean die-out
When an engine reaches operating temperatures, do the turbine blades expand or contract? Expand
If the kinetic energy of air flowing through a duct increases, the potential energy: Decreases
What does EPR represent in turbofan-powered aircraft? Thrust being produced
Fuel flow for a gas turbine engine is indicated in what measurement? Pounds per hour
What must be followed when removing the propeller from a turboprop engine? Manufacturer's instructions
The permanent deformation of turbine blades caused by high temperatures is known as: Creep
What is the purpose of air passing through the combustion chamber of a turbine engine supports combustion and cool the engine
What is the primary advantage of an axial-flow compressor over a centrifugal compressor? Greater pressure ratios
What is the profile of a turbine engine compressor blade? reduced blade tip thickness
How is the blending of blades and vanes performed? Parallel to the length of the blade using smooth contours
In what section is the fuel and air mixed? Combustion
Combustion occurs at a constant: Pressure
What are not acceptable to any extent in turbine blades? Cracks
Where is the turbine discharge pressure indicator sensor located Immediately aft of the last turbine stage
Turbine engine tachometers are calibrated in what measure of units? Percent of engine RPM
The development of a hard, glossy surface on bearing surfaces in the presence of oil, heat, and pressure is known as: Glazing
Turbine nozzle diaphragms located on the upstream side of each turbine wheel, are used in the gas turbine engine to: Increase the velocity of the heated gases
During inspection, engine components exposed to high temperatures may only be marked using: Chalk
What are two basic elements of the turbine section in a turbine engine? Rotor and stator
Who establishes mandatory replacement times for critical components of turbine engines? Manufacturer
Who is authorized to overhaul turbine engines? manufacturer or overhaul facility
Why should shop air never be used to dry a turbine bearing? Shop air can cause corrosion
Visual inspection is accomplished using: A light and magnifying glass
Where do stress rupture cracks usually appear on turbine blades? Across the leading or trailing edge at a right angle to the edge length
What kind of turbine engine compressor has vanes on both sides of the impeller? Double entry centrifugal compressor
Axial-flow compressors have what disadvantages? high weight and high starting power requirements
A severe stall of a compressor wheel in a gas turbine engine is known as: Hung stall
What section is divided into primary and secondary paths in order to properly function? Combustion
The shape and size of the exhaust section and it's components has direct effect on: Turbine Inlet Temperature
What is used to supply power to the aircraft when the engines are not running? APU
Galling is caused by what? Severe rubbing of turbine blades
How many magnetos are typically used on gas turbine engines? 0
What must be done before inspecting the engine nacelle? Clean the nacelle
Before attaching a sling to an engine hoist, what must be done? Check hoist capacity limits
Nozzles accomplish what two tasks? Convert thermal energy into mechanical and direct gases to turbine blades
Creep is caused by: Continued or excessive heat and centrifugal force
Inlet air density is affected by: Ambient temperature, altitude, and speed of the aircraft
Thermal efficiency of the engine is affected by: TIT, compression ratio, and turbine and compressor efficiency
Stress ruptures develop from: excessive heat stress
A purpose of the shrouds on the turbine blades of an axial-flow engine is to: Reduce vibration
Dirt particles in the air being introduced into the compressor of a turbine engine will not form a coating on: Turbine blades
What is used to support some long fan blades making them more resistant to bending forces? Mid-span shroud
When an excessively rich fuel/air mixture is ignited, it is known as: A hot start
During a normal startup the engine fails to reach idle speed, this is known as: A hung start
Fuel flow should be turned off and the engine should continue to be motored with starter when? If a fire occurs during starting cycle
When shutting down a gas turbine engine, a 30 second idling is recommended why? oil system scavenging and allow component temperatures to stabilize
What is takeoff power rating? The amount of power an aircraft engine is permitted to produce during takeoff.
Maximum cruise power is also known as: Maximum continuous power
Though TBO for the engine is not required of turbines, the manufacturer will require: overhaul of individual components
Why do some turbine engines have more than one turbine wheel attached to a single shaft? To extract more power
Hot streaking can be caused by: A partially clogged fuel nozzle
Main bearing oil seals are usually what type? Labyrinth and/or carbon rubbing
Increase pressure and reduce velocity is the purpose of what section? Diffuser
Turbine blades are classified as: impulse, reaction, and impulse-reaction
What is used to cool the components of the turbine section? Engine bleed air
The jet nozzle provides the exhaust gases with a final boost in what? Velocity
What increases thrust by accelerating exhaust gases? Afterburners
Thrust reversers are used to assist turbojet or turbofan powered aircraft with what? Braking
A force that tends to pull an object apart is known as: Tension
Wing-mounted turbofan engines often have little ground clearance making them more vulnerable to: Blade erosion
Stagnation density is a single variable combined from: Temperature, altitude, and airspeed
Ultra-high bypass prop fan is known as: UDB
Air entering the compressor must be: slower than the speed of sound
What is used for cabin pressurization, air conditioning, fuel system deicing, and pneumatic engine starting? Compressor bleed air
In a dual axial-flow compressor, the first stage turbine drives the N2 compressor
A raised area indicating separation of a surface layer from a base metal is known as: Blister
The formation of pockets on the surface of a metal is known as: Pitting
High static loads cause rounded indentations in bearing races known as: Brinelling
The condition that occurs when mid-span shrouds overlap from excessively worn mating surfaces is known as: Shingling
The ratio of actual power produced divided by thermal energy in the fuel consumed is known as: Thermal efficiency
An imbalance between inlet velocity and compressor rational speed is known as: compressor stall
Created by: Ms.Fietzek



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