15.12 Air Systems Flashcards
Because the burning process is continuous, what must be done?
Cooling air must be passed through inside of engine.
What is the temp of the hot engine section?
800 - 1150 C
What’s the critical lubrication point of the engine?
Exhaust turbine bearing.
What provides secondary airflow for cooling?
Bleed air from compressor early stage.
Where is zone 1 cooling?
Cooling around fan case.
Cooled by RAM air.
Where is zone 2 cooling?
From the fan duct upper part to exhaust lower part into fan air stream.
Cooled by fan air.
Where is zone 3 cooling?
Around the HP compressor to turbine cases.
Where does ice build up in an engine?
Inlet duct and IGVs.
How is Engine anti ice controlled?
Automatically by a switch in flight deck.
What is the temperature of the compressor rear stage?
350- 400 C
What can be said about the combustion section outer casing?
Has a perforated inner liner.
How is the turbine disc cooled?
Engine bleed air.
How are turbine guide vanes and blades cooled?
By Compressor Discharge Air.
What seals engine bearing chambers?
LP compressor bleed air.
What is the purpose of pressurised air creating an additional sealing effect?
Prevents oil escaping the bearing chamber.
