Turbine Engine Flashcards
Defined the term thermal efficiency in regards to aircraft engine
The ratio of net work produced by engine to the chemical energy supply and forms of fuel
what are the major component of a typical gas turbine engine?
Air inlet, compression section, combustion section, turbine section, exhaust section and accessory section
Why are the two principal type of compressors used in turbo jet aircraft?
Axial flow, and centrifugal flow
What are the four combustion chamber system?
Can-annular, annular, reverse flow annular type and can type
what is the purpose of inter-connector tubes between can type combustion chamber?
To spread the flame to the combustion chambers that are not equipped with igniter plug during engine starting
What prevents burning of the liner walls in can type combustion chamber
Louver provided along the axial length of the liners to direct a cooling layer of air along the inside wall of the liner
What type of damage may be found when inspecting compressor blade?
Dent, scratches, gouges, galling, burns, bars, piting, and cracks
What is the location and function of the diffusion section in a turbine engine?
The diffuser is the divergent section of the engine located between the compressor section and the burner can. The function is to change high velocity compress discharge air to static pressure.
Where are stress ruptured crack most likely to occur on turbine Blade
Hairline cracks on or across the leading edge or trailing edge of the blade .cracks appears at right angle to the edge length
How are compressor blade attached to disk type rotor?
fitted by bulb type ,fir tree, or dove trail type root that are lock by means of screws, peening,locking wires, pins or keys
What is the purpose of nozzle diaphragm or turbine nozzle?
They change a portion of heat and pressure energy into velocity energy. They also deflect the gas so they strike the turbine at the most efficient angle for maximum turbine rotation.
What is the major difference between turboprop and turbo jet engine?
Turbo prop engine has more turbine stages than turbojet engine. turbo prop turbine must also driven a propeller.
What is a turbofan engine?
Same principle as the turbo prop, except the propeller is replaced by a duct-enclosed axial flow fan
What is the effect of air density on the thrust of turbine engine
Air density determine the mass of it is used by the jet engine.the factor that affects are the temperature and the pressure of air. If density increases, thrust increase and vice versa. Increasing air temperature entering the engine, will cause a decrease in air density and thrust. An increase in air pressure entering the engine will cause an increasing air density and thrust. With a given throttle setting engine thrust vary if the temperature or the pressure to air entering the engine change.
What are the two common most type of thrust reverser?
Mechanical blockage and aerodynamic blockage type
What is a split compressor system in a turbine engine
Required to concentric shaft oining the turbine stages to their respective r compressor
What is one method of relieving thermal stress on the turbine disk
To direct cool bleed air back on the face of the disk
What may be the indication of a turbo jet engine is out of trim
Engine has high exhaust gas temperature for take off
What does it mean when you have high EGT, high fuel flow , and low thrust or power
Pending engine failure or low compression
What is a free turbine
Turbine wheel drives the propeller or helicopter transmission instead of compressor
What is the main purpose of thrust reversers
To back off airplane or slowing the aircraft down to effective braking speed
What are the advantage of turbofan engine over turbojet engines
Use a fan to bypass more air around engine core and provide thrust. This advantage is provides additional thrust without increasing fuel flow
What methods are commonly used to accomplish turbine engine compressor field cleaning ?
Fluid wash and abrasive grits blast
What would the possible cause be for a turbo jet or turbo engine having a high EGT, low rpm and high fuel at all engine pressure ratio sitting
Possible turbine damage or loss of turbine efficiency
Defined term operating flexibility in regard to aircraft engine
Ability of an engine to run smoothly and give desired performance at all speed from idling to full power output
How are conventional reciprocating engine classified
Cylinder arrangement and method of cooling
What are the different types of piston rings?
Compression ring , oil control ring, scraper ring
What are the main causes of a cylinder having low compression?
Broken piston ring, rings not seated properly ,burn valve ,valve not seated properly
What is the purpose of the oil control rings? 
To control the thickness of the oil film on the cylinder wall
What type of piston rod are commonly found in radial engine
Master and articulating
Want may be the result of installing piston ring correctly
Excessive oil consumption
What type of bearing are generally used in a reciprocating engine?
Plain ball roller type
What is the indication of valve blow by
By hissing or a whistle when pulling the propeller true by hand
What is the purpose of using more than one spring valve closing
To eliminate valve float caused by spring surge
What is the purpose of valve overlapping?
Better volumetric efficiency and lower the cylinder operating temperature
Describe the inspection,you would give to the valve spring during engine overhaul
Clean thoroughly and look for signs of overheating, cracks, broken end and compression strength
What is the purpose of using Valve with sodium filled stem
Excellent heat conductor, and dissipate heat well
What causes engine sudden stoppage?
Striking an object or engine seizure due to internal damage
What type of inspection must be made after sudden stop picture of an engine?
Most manufacture require a complete engine tear down and inspection
What is the purpose of crankshaft dynamic dampers use an aircraft engine?
To overcome to force which caused deflection of the crankshaft and torsional vibration. (to reduce the vibration caused by torsional load)
How would you make a run out check on the crankshaft that is still installing the engine
Remove the propeller from the crankshaft ,placed dial indicator in front of the crank case, adjust the position of gauge needle, so that it’s touching the shaft rotate the crankshaft and check for misalignment.
What is detonation?
When fuel reach beyond its limit temperature and compression that will ignite simultaneously and burn with explosive violence this explosion burning of the last portion of charge it’s called detonation
What cylinder is engine magneto timing based on?
Number one cylinder at around 30° TDC of compression stroke
What is a Engine sudden speed production?
Went to propeller, strike an object, but continues to run
Why can’t be alone about the condition of the engine by studying the result of a compression check?
You can determine if the valve ,piston rings and Pistons adequately, sealing the combustion chamber
How can a cold cylinder be located on a double roll radial engine?
Old tool called magic wand and modern infrared laser thermometer
What instrument can be used to check for bore out of roundness?
Dial indicator, telescopic, scope, and micrometer
What would a cold cylinder indicate?
No combustion inside the cylinder due to no ignition or clogged fuel nozzle
Where is crack most likely to occur on a piston
Where the piston pin/wrist, pin connect
What is the running valve clearance on a Engine equipped with hydraulic lifters?
Zero
What level is used to adjust the manifold pressure in a reciprocating engine?
Throttle control
On the engine to fix pitch propeller what is the relationship between the manifold pressure in the rpm
Rpm increase also manifold air pressure increase
What should be done to repair a loose stud in an engine crank case
Removed the loose stud and inspect the whole for size and condition of the thread . It may require to use a oversize stud
