Engine Flashcards
PW220 engine description
Twin-spool, low-bypass, high-response turbofan jet engine
thrust to weight ratio block 25/32
Mil - 14,000 lbs 54:1
AB - 25,000 lbs 96:1
Major engine components
CIVVs 3 stage fan 10-stage axial flow compressor combustion chamber compressor and fan turbines MFC AB Engine Gearbox DEEC
CIVVS function
control AOA of all air entering the fan to prevent stalls, controlled by DEEC and powered by fuel pressure, automatic in PRI, fixed position in SEC
5 basic engine modules
Inlet Fan, core engine, fan drive turbine, AB and Nozzle, engine-mounted gearbox
Inlet Fan
3 stage compressor, CIVVs, 100% of airflow, 10,000 rpm, 3:1 compression ratio, anti ice system
Anti-ice
from 13th stage hot bleed air, controlled by DEEC and ANTI ICE switch, DEEC prevents anti-ice ops above 30,000’ and when engine inlet/bleed air temps are high
Core Module
heart of the work: 60% of the air, 10 stage compressor goes to 24:1, combuster, 20stage high pressure turbine
RCVVs
first three stages of the comprssion stator blades function like CIVVs, programed by DEEC in PRI, hydromechanically controlled by MFC in SEC
start bleed strap located at the ____ stage function:
7th stage ; vents pressure during start
Combustion chamber had ___ fuel injectors ___ spark plug igniters that operate continuously when throttle in operating range ___% and above
16 fuel injectors, 2 spark plug igniters, >12% rpm
Fan drive turbine module located aft of compressor turbine powers the ________ via inner spool, and ____ thermocouples measure engine air temp (FTIT) ; exit air mixes with fan bypass air
inlet fan ; 7 thermocouples
AB ignition has ____ separate igniters and activates for up to ___ seconds until light off is detected by the AB light-off detector, or DEEC terminates AB Fuel flow after ___ attempts
2 igniters ; 3 seconds ; 3 attempts by DEEC if left in AB
The AB _____ _____ probe prevents AB cancellation contrail by venting fuel into gas stream
Signature elimination probe
Operating in SEC, the nozzle is open/closed by exhaust pressure
Closed