# Shared Flashcard Set

avi145
turbine engines
180
Aviation
Undergraduate 1
02/25/2015

## Cards Return to Set Details

Term
 Newton's first law of motion
Definition
 A body at rest tends to remain at rest and a body in motion tends to continue in motion in a straight line unless caused to change its state by an external force
Term
 Newton's second law of motion
Definition
 The acceleration of a body is directly proportional to the force causing it and inversely proportional to the mass of the body
Term
 Newton's third law of motion
Definition
 For every action, there is an equal and opposite reaction
Term
 Energy transformation cycle of a gas Turbin engine
Definition
 Intakecompressioncombustionexhaust
Term
 What is thrust
Definition
 A reaction force measured in poundsAction= acceleration of air massReaction= Forward movement
Term
 Bernoulli's principle
Definition
 Velocity increase = pressure decreaseVelocity decrease = pressure increase
Term
 Factors affecting thrust
Definition
 Temperature.Humidity.Altitude.Airspeed.Engine rpm.Fan efficiency.Water injection. Afterburner
Term
 Standard day
Definition
 0 ft altitude59°F29.92 in/hg (mercury)
Term
 Four types of gas turbine engines
Definition
 TurbojetTurbofanTurbopropTurboshaft
Term
 Fuel heater
Definition
 Heat exchanger- Engine oil or Bleed airFuel flows continuously
Term
 Simplex nozzle
Definition
 Provides single spray pattern
Term
 Duplex nozzle
Definition
 2 independent discharge orfices, (small & large)Small orifice = Center- Primary fuel (idle)Large orifice = around center- Secondary fuelCan be single or dual line
Term
 P&D valve
Definition
 Pressurization and Dump ValveUsually used in fuel systems with dual line duplex nozzles-pressurize fuel in primary and secondary manifolds-empty or dump all of the fuel in the 2 manifolds upon engine shutdown
Term
 What is the Brayton cycle?
Definition
 Simultaneous / continuous intake, compulsion and compression at constant pressure
Term
 The function of the turbine in a turbojet is to drive the ______
Definition
 Compressor blades
Term
 Determine engine that uses a separate turbine to drive a reduction gearbox, and / or propeller is a ________ engine
Definition
 Free turbine
Term
 What are three and villages of a turbofan over a turbojet engine
Definition
 More efficient / less fuel Fan will divert FODQuieterHigh thrust at low speeds
Term
 The ratio of the amount of air that passes through the fan to that which flows through the core of the engine is called ________
Definition
 Bypass ratio
Term
 Convergent subsonic air flow
Definition
 Velocity increasesPressure decreases
Term
 Divergent subsonic air flow
Definition
 Pressure increasesVelocity decreases
Term
 Convergent supersonic air flow
Definition
 Velocity decreasesPressure increases Density increases
Term
 Divergent supersonic air flow
Definition
 Velocity increasesPressure decreasesDensity decreases
Term
 What is the cold section consist of
Definition
 InletCompressorDiffuser
Term
 What speed must the air entering the engine be?
Definition
 Subsonic
Term
 what are the two sections into which a gas turbine engine can be divided?
Definition
 HotCold
Term
 Can let ducts are part of ________
Definition
 The airframe
Term
 Name two classifications of inlet ducts
Definition
 SupersonicSubsonic
Term
 What is a stall
Definition
 When an airfoil exceed its critical angle of attack
Term
 What is the use of inlet guide vanes
Definition
 -Slightly reduces the amount of air flowing through the engine (to prevent compressor stall) -Direct air to the first stage of the compressor at the proper angle. -Used on axial flow turbine engines
Term
 Two types of compressors with respect to air flow
Definition
 Centrifugal type.Axial type
Term
 Three types of compressors with respect to performance
Definition
 Single stage.Two Stage.Multiple stage.
Term
 What is a compressor stall?
Definition
 Occurs when the compressor blades angle of attack exceed the critical angle of attack, at this point smooth air flow is interrupted and turbulence is created with pressure fluctuations
Term
 What a profile tip
Definition
 Reduced blade thickness at tip
Term
 Three types of rotor blade roots
Definition
 BulbFir treeDovetail
Term
 What is compressor air supplied for
Definition
 Cabin pressurization.Kevin heating.Cabin cooling. Cooling turbine inlet guide vanesCooling turbine wheel.Deicing systems.Anti-icing systems.Pneumatic engine starting
Term
 Where is the diffuser located?
Definition
 Between the compressor and combustion chamber
Term
 What the diffuser do?
Definition
 Produces electricity and increases pressureDivergent shapePoint of highest pressure in the engine
Term
 Pressure of air passing through the compressor is a measure of _____ energy
Definition
 Potential
Term
 Air taken from the compressor to anti-ice the inlet duct is known as ______ air
Definition
 Bleed
Term
 What are other uses for bleed air?
Definition
 CoolingPressurize cabinA.c.
Term
 Name two types of compressors used on turbine engines
Definition
 Axial Centrifugal
Term
 Name the three components of a centrifugal compressor
Definition
 ImpellerDiffuserCompressor manifold
Term
 Name the components of an axial flow compressor
Definition
 StatorsRotors
Term
 A compressor blade with a tip having a decreased thickness is known as _______
Definition
 Profile
Term
 Two design features that may be used to prevent or minimize compressor stalls are
Definition
 Bleed airVIGV (or VSV)
Term
 Two variables that affect compressor stall are
Definition
 RPMvelocity of airflowThrough compression
Term
 What is the Hot Section consist of?
Definition
 Combustion sectionturbine sectionexhaust section
Term
 Located directly behind the diffuser=Where the fuel & air is mixed & burned=
Definition
 Combustion section
Term
 What does the combustion section consist of?
Definition
 One or more combustion chambersa fuel injection systeman ignition systeman ignition sourcea fuel drianage system
Term
 ATA 72
Definition
 Engine
Term
 ATA 71
Definition
 Powerplant
Term
 ATA 83
Definition
 Accessory Gearbox
Term
 ATA 12
Definition
 Servicing
Term
 ATA 73
Definition
 Fuel and Control
Term
 What is a LRU?
Definition
 Line Replaceable Unit
Term
 Name 4 LRU's that could be found attached to a turbine engine gearbox.
Definition
 Hydraulic pumpGeneratorsOil pumpStarterFuel Control Unit (FCU)Boost pumpFuel PumpOil cooler
Term
 In addition to powering aircraft accessories, what other secondary function does the gearbox serve?
Definition
 Oil sumpLubrication
Term
 On a dual spool turbofan, which rotor drives the accessory gearbox?
Definition
 N2
Term
 What are 2 types of fuels used for turbine engines?
Definition
 Jet AJet B
Term
 what is the difference of the 2 turbine fuels?
Definition
 Jet A= primarily keroseneJet B= 70% gasoline, 30% kerosene
Term
 Name the 3 types of turbine engine fuel nozzles.
Definition
 SimplexDuplexVaporizing
Term
 What are the 2 functions of the P&D valve?
Definition
 Divide flowDump
Term
 [image]
Definition
 1. Tank2. Boost pump3. Shut Off Valve (SOV)4. Fuel Pump5. Low Pressure Pump6. Fuel Heater7. Bypass8. High Pressure Pump9. Bypass10. SOV (air)11. Filter12. Differential pressure switch13. Bypass14. Fuel Control15. Fuel flow transmitter16. oil cooler17. P&D valve18. Primary19. Secondary20. Nozzle21. Fuel dump
Term
 [image]
Definition
 Convergent Duct= Velocity = DecreasesPressure = IncreasesDensity = IncreasesDivergent Duct= Velocity = Increases Pressure = DecreasesDensity = Decreases
Term
 [image]
Definition
 Convergent Duct= Velocity = IncreasesPressure = DecreasesDivergent Duct= Velocity = DecreasesPressure = Increases
Term
 An increase in airspeed will cause a turbojet engine's thrust to ______
Definition
 Decrease
Term
 Pt2 refers to ______
Definition
 Total pressure at station 2
Term
 Ducts in the diffuser of a turbine engine are _________ in shape.
Definition
 Divergent
Term
 What are two types of turbine engine compressors?
Definition
 AxialCentrifugal
Term
 In turbine engine, the air that is used for combustion is known as __________
Definition
 Primary Air
Term
 What is the most common type of turbine blade (shape) used on modern turbine engines?
Definition
 Impulse-Reaction
Term
 Between each row of rotating blades in a turbine engine compressor, there is a row of stationary blades which act to diffuse the air. these stationary blades are called __________
Definition
 Stators
Term
 What is the primary factor which controls the pressure ratio of an axial-flow compressor?
Definition
 Number of Stages
Term
 Name 3 types of combustion sections used in aircraft turbine engines.
Definition
 CanAnularCan-Anular
Term
 On an aircraft turbine engine, operating at a constant power, the application of engine anti-icing will result in ______________
Definition
 Lower ThrustHigher Temperature
Term
 Name 4 main factors that affect thrust
Definition
 TemperatureAltitudeAir densityRPMAir SpeedFan EfficiencyAfterburner
Term
 What is the purpose of a bell mouth inlet?
Definition
 To allow smooth airflow into the engine at low speeds
Term
 What are 4 uses for bleed air from a turbine engine?
Definition
 Cabin PressurizationCabin HeatingCabin CoolingCooling turbine inlet guide vanesCooling turbine wheelDeicing systemsAnti-icing systemsPneumatic engine starting
Term
 ATA 79
Definition
 Lubrication
Term
 ATA 11
Definition
 Required Placards
Term
 Name 2 types of Turbine engine oils.
Definition
 Type IType II
Term
 What type of oil system is typically found on turbine engines?
Definition
 Dry Sump
Term
 Why do turbine engine manufacturers recommend servicing oil after engine shut down?
Definition
 Prevent over servicing
Term
 Name 3 types of positive displacement pumps used for fuel or oil systems.
Definition
 GearVaneGerotorScavange
Term
 What is the purpose of the thermostatic valve in a turbine engine cooler?
Definition
 controls the amount of oil that flows to the coolerOil cold – bypass valve open – oil will bypass the coolerOil hot – bypass valve closed – oil will flow through the cooler
Term
 According to Federal Aviation Regulations, oil tank fillers on turbine engines must be marked with _________
Definition
 "Oil"
Term
 Describe the operation of an indicating chip detector.
Definition
 metal chips in oil are trapped. when build up or large enough chips are captured they bridge a gap in the mesh filter completing an electrical circuit and an indicating light is illuminated
Term
 Name 2 types of oil seals used on a turbine engine.
Definition
 LabyrinthHelicalCarbon
Term
 What is the primary purpose of the fuel to oil heat exchanger?
Definition
 To Cool Oil(oil cooler)
Term
 What are 2 things that will happen if the oil filter becomes blocked?
Definition
 lights up warning lightbypass valve opens (bypassing filter completely)
Term
 What is a Hot Tank oil system?
Definition
 Oil is cooled after leaving tank (oil is hot in tank)
Term
 What is the purpose of the dwell chamber of a turbine engine oil tank?
Definition
 chamber where oil is temporarily stored to help eliminate bubbles and foam
Term
 What color are turbine engine fuels?
Definition
 Straw
Term
 What is PRIST? What is it's purpose? How does it work?
Definition
 Fuel additive-Prevents ice and bacterial contamination--As the fuel temperature decreases, the additive combines with the water in greater concentrations. This combination will keep the freezing point of the water lower than the temperature of the fuel.
Term
 Describe the operation of a cooled oil cooler/fuel heater.
Definition
 Heat Exchanger–Engine Oil or Bleed Air.Fuel flows through continuously.Activated manually or automatically.
Term
 What is the airflow through the combustor divided into?
Definition
 PrimarySecondary
Term
 Explain the Primary path of airflow through the combustor.
Definition
 25% to 35% of incoming air.Passes through a set of swirl vanes, gives air a radial motion & slows velocity.
Term
 Explain the Secondary path of airflow through the combustor.
Definition
 65% to 75% of incoming airSecondary air for cooling
Term
 What are the types of combustion chambers?
Definition
 Can type/ Multiple-can typeAnnular or Basket typeCan Annular type
Term
 What are the 4 basic parts of the Turbine section?
Definition
 CaseStatorShroudRotor
Term
 What are the other names for the turbine Stators?
Definition
 Turbine nozzleTurbine Guide VaneTurbine nozzle Diaphragm
Term
 What is the part with the hottest heat to metal temperature in a turbine engine?
Definition
 Turbine Nozzle
Term
 What does the turbine rotor consist of?
Definition
 ShaftTurbine rotor or wheel
Term
 What is the shape of Turbine Blades? Why?
Definition
 Airfoil shapedDesigned to extract the maximum amount of energy from the flow of hot gases
Term
 What is the most common Turbine Blade attachment shape?
Definition
 Fir Tree
Term
 What are the classifications of Turbine Blades?
Definition
 Impulse TypeReaction TypeImpulse-Reaction Type
Term
 What is the accessory gearbox powered by?
Definition
 Engine's main power shaft
Term
 ATA 77
Definition
 Engine indicating
Term
 ATA 74
Definition
 Ignition
Term
 What are the ignition system Components?
Definition
 Transformer/ exciter box (2)Ignition Lead (2)Igniter (2)
Term
 Basic parts of a Igniter
Definition
 Shell/BodyInsulatorInternal sealsElectode
Term
 2 types of Igniters
Definition
 Low voltageHigh voltage
Term
 Types of starters
Definition
 Starter-GeneratorsCombustion Starters Gas turbine type Cartridge typeAir TurbineDirect Cranking Starter
Term
 Engine Instrumentation
Definition
 Compressor speed Engine Pressure RatioTurbine discharge pressureTorquemeterFuel Flow indicatorOil pressure gageOil teperature gage Exhaust gas temperature - EGTEngine Indicating & Crew Alerting System (EICAS)
Term
 How is Compressor speed monitored?
Definition
 -Tachometer in % RPM-Separate Tach for each compressor
Term
 what is the engine pressure ratio? what does the EPR gauge indicate?
Definition
 Ratio of Turbine Discharge Pressure to Compressor Inlet PressureIndicates amount of thrust produced.Pressure taken at Pt2 & Pt7
Term
 Turbine engine Starting Safety check
Definition
 Master Switch – OFFBattery Switch – OFFLanding Gear Handle – DOWNGenerator Switches – OFFStarter Switch – OFFIgnition Switch – Off (Circuit Breaker IN)Power Lever - Cutoff
Term
 Turbine engine starting Pre-Start Checks
Definition
 Ground Power – Verify correct voltage & air pressure.Master Switch – ONBattery Switch – ONExternal Power Switch – ONFuel Boost Pump(s) – ONFuel Valve(s) Selected – OPENLow Fuel Pressure Light – OFF
Term
 Starting a Turbine Engine
Definition
 Start Switch – Start-Watch RPM indicator25% RPM – Power Lever to IDLE Position-Watch for Fuel Flow-Watch EGT gage-Watch oil pressure gage
Term
 What is a hot start?
Definition
 If EGT exceeds allowable limits(SHUT OFF FUEL IMMEDIATELY)
Term
 What is a Hung Start?
Definition
 Engine Fails to accelerate or reach idle RPM(shut down immediately)
Term
 What do you do if a fire starts in the engine during start cycle?
Definition
 Cut off fuelContinue motoring engine with the starter
Term
 Engine shutdown procedure...
Definition
 Engine checks completeRun engine at idle for 30 – 60 secondsPower Lever – CutoffFuel Valve(s) Selected – ClosedFuel Boost Pump(s) – OFFExternal Power Switch – OFFBattery Switch – OFFMaster Switch - OFF
Term
 Primary Uses of an APU
Definition
 To drive an electric generatorSupplies bleed air for heating, cooling, anti-ice, and engine starting
Term
 ATA 76
Definition
 engine control
Term
 ATA 80
Definition
 Starting
Term
 ATA 49
Definition
 APU
Term
 ATA 70
Definition
 Standard practices
Term
 ATA 4
Definition
 Airworthiness limitations
Term
 ATA 5
Definition
 Time limitations
Term
 subsonic planes have what type of exhaust cone?
Definition
 Convergant
Term
 Any type of maintenance that can be done while the engine is installed on the aircraft.
Definition
 Line Maintenance
Term
 Maintenance the requires the engine to be taken off the aircraft. (normally performed at an overhaul facility)
Definition
 Shop Maintenance / Heavy Maintenance
Term
 Adjust fuel control for maximum rated thrust
Definition
 Trimming
Term
 powerplant components
Definition
 Fan and boosterHigh pressure compressorCombustorHigh pressure turbineLow pressure turbineAccessory drive
Term
 ATA 76
Definition
 engine control
Term
 ATA 80
Definition
 Starting
Term
 ATA 49
Definition
 APU
Term
 ATA 70
Definition
 Standard practices
Term
 ATA 4
Definition
 Airworthiness limitations
Term
 ATA 5
Definition
 Time limitations
Term
 subsonic planes have what type of exhaust cone?
Definition
 Convergant
Term
 Any type of maintenance that can be done while the engine is installed on the aircraft.
Definition
 Line Maintenance
Term
 Maintenance the requires the engine to be taken off the aircraft. (normally performed at an overhaul facility)
Definition
 Shop Maintenance / Heavy Maintenance
Term
 Adjust fuel control for maximum rated thrust
Definition
 Trimming
Term
 powerplant components
Definition
 Fan and boosterHigh pressure compressorCombustorHigh pressure turbineLow pressure turbineAccessory drive
Term
 ATA 76
Definition
 engine control
Term
 ATA 80
Definition
 Starting
Term
 ATA 49
Definition
 APU
Term
 ATA 70
Definition
 Standard practices
Term
 ATA 4
Definition
 Airworthiness limitations
Term
 ATA 5
Definition
 Time limitations
Term
 subsonic planes have what type of exhaust cone?
Definition
 Convergant
Term
 Any type of maintenance that can be done while the engine is installed on the aircraft.
Definition
 Line Maintenance
Term
 Maintenance the requires the engine to be taken off the aircraft. (normally performed at an overhaul facility)
Definition
 Shop Maintenance / Heavy Maintenance
Term
 Adjust fuel control for maximum rated thrust
Definition
 Trimming
Term
 powerplant components
Definition
 Fan and boosterHigh pressure compressorCombustorHigh pressure turbineLow pressure turbineAccessory drive
Term
 ATA 76
Definition
 engine control
Term
 ATA 80
Definition
 Starting
Term
 ATA 49
Definition
 APU
Term
 ATA 70
Definition
 Standard practices
Term
 ATA 4
Definition
 Airworthiness limitations
Term
 ATA 5
Definition
 Time limitations
Term
 subsonic planes have what type of exhaust cone?
Definition
 Convergant
Term
 Any type of maintenance that can be done while the engine is installed on the aircraft.
Definition
 Line Maintenance
Term
 Maintenance the requires the engine to be taken off the aircraft. (normally performed at an overhaul facility)
Definition
 Shop Maintenance / Heavy Maintenance
Term
 Adjust fuel control for maximum rated thrust
Definition
 Trimming
Term
 powerplant components
Definition
 Fan and boosterHigh pressure compressorCombustorHigh pressure turbineLow pressure turbineAccessory drive
Term
 A sever condition of chafing or fretting in which a transfer of metal from one part to another occurs is called...
Definition
 Galling
Term
 What must be done after the fuel control unit has been replaced on an aircraft gas turbine engine?
Definition
 Engine Trim
Term
 Why is a cool-off period necessary prior to shutdown of a turbine engine?
Definition
 So the case does not shrink around bladesSo cracking does not occur
Term
 What is the purpose of an under-current relay in a starter-generator system?
Definition
 Determines that a starter is spinning fast enough to shut itself off
Term
 What is the primary advantage of pneumatic (air-turbine) starters over comparable electric starters for turbine engines?
Definition
 Power-to-weight ratio
Term
 Describe the basic procedure for removing a turbine engine ignition system.
Definition
 Turn power offPull circuit breakerremove leadsWait to dischargeremove
Term
 Describe the basic start procedure for a typical turbine engine.
Definition
 starterignitionadd fuel last
Term
 How is an APU cooled down prior to shutdown?
Definition
 turn off bleed air loads and electricity
Term
 (T/F)When an aircraft has an APU on board, an engine-mounted starter is required
Definition
 True
Term
 (T/F)Propeller RPM is the primary indication of thrust for a turboprop engine
Definition
 False(Torque)
Term
 (T/F)EGT is a useful indication of thrust produced in a turbine engine
Definition
 False(used for temperature)
Term
 What are the factors that can cause a hung start?
Definition
 improper fuel controlproblem with starterstarter doesn't crank long enoughbattery dies
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