ENGINES Flashcards
5 Engine Sections
Inlet
Compressor
Combustor
Turbine
Exhaust
Inlet cowling heated by…
fifth stage bleed air via the anti-ice valve as well via the perforated slits
Combustion section consits of…
flow-through, annular combustion chamber
2 igniters
12 fuel injectors (ODV fed)
What does the Ng turbine drive?
Compressor
Accessory Gearbox (AGB)
What does the Np turbine drive?
Power turbine drive shaft (turns inside Ng turbine coaxially)
High speed shaft (connects to input module)
Where is TGT sensed?
between Ng and Np turbine
30% of airflow through the engine is used for what?
Combustion process
70% of airflow through the engine is used for what?
- Compressor inlet temperature (T2) air.
- Compressor discharge pressure (P3) air.
- Combustor and turbine cooling.
- Engine oil seal pressurization.
The AGB is driven by what?
rotor via a radial drive shaft from the Ng turbine drive shaft
The rear face provides drive pads for the…
- engine starter
- HMU
- IPS blower
- Overspeed and Drain Valve (ODV)
Engine Control System Purpose
- maintain constant Np/Nr
- Basic system operation is governed through the interaction of the EDECU and HMU
- HMU provides gas generator control
- EDECU trims the HMU to
satisfy the requirements of the power turbine load and reduce pilot workload
Engine Control System Components
HMU
ODV
EDECU
engine-driven alternator
fuel flow control valves
If the PCL is momentarily advanced to LOCKOUT
and then retarded, the PCL is used to manually control…
Np and Ng.
TGT limiting, Np governing, and load sharing functions are deactivated and must be manually controlled. The Np overspeed protection system is retained when in
LOCKOUT via a direct link between the EDECU
The engine-driven fuel boost pump mounted on the forward side of the AGB is designed to:
- Provide reliable suction feed from the aircraft fuel tank to the engine, minimizing vulnerability and fire hazard in the event of damaged fuel lines.
- Provide discharge pressure to satisfy the minimum inlet pressure requirement of the HMU or high-pressure fuel pump.
Hydromechanical Control Unit Components
- high-pressure fuel pump
- Ng governor
- metering valve
- Linear Variable Displacement Transducer (LVDT)
- torque motor servo
- variable geometry vane servo
- vapor vent
- shutoff valve