15.12 Air systems Flashcards
where is secondary airflow for cooling supplied from?
the early compressor stages
what is bleed air used to cool?
the turbine disc and exhaust bearing
what is the acceptable temperature range?
800-1100 c
what is zone 1?
the area around the fan case
what is zone 2?
it is cooled by fan air from the upper part of the upper part of the fan duct and is exhausted back into the air stream
what is zone 3?
the area around the high pressure compressor
what are the two methods to activate anti ice?
manual or automatic
where is cooling air for the late stage compressor taken from?
the intermediate compressor stage
where is air directed into the combustion for cooling?
Primary 20-30% - into the liner
secondary 70-80% - enters at high velocity
where is cool air directed into the turbine?
each side of the disc
how are nozzle guide vanes and turbines cooled?
compressor discharge air
what can low pressure compressor air be used for?
sealing engine bearing chamber
how is air finally vented overboard after it enters the bearing compartment?
through the N1 rotor shaft
what is bowed rotor?
after engine shut down due to different expansion rates the engine can bend
