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