M15.3 Inlet Flashcards
Engines use what to straighten the airflow and direct it into the first stages of compression?
Inlet guide vanes (IGV)
What is RAM recovery?
The added pressures at the inlet of the engine increasing pressure and airflow to the engine
By having two air inlet ducts it allows you to what?
Shorten the length of the inlet
Disadvantage of divided entrance air inlets?
Flight manoeuvres can cause ram air pressure imbalances. Results in slight loss of power
Airflow into the engine must always be below what Mach?
1.0
Inlet ducts are designed like diffusers why?
To decrease velocity and increase static pressure of the air
What is used to prevent the engine readily ingesting any items drawn into the intake?
Compressor inlet screen
A bell mouth inlet is usually installed on engines undergoing what?
Testing in test cell
On turbofan engines how does the fan reduce damage from FOD?
Due to the centrifugal force, FOD is thrown radially outwards and passes over the fan discharge rather than through the core
How does anti icing work on turbofan inlets?
Warm bleed air is drawn from engine and circulated on the inside of the inlet lip for anti icing
Negatives of ice in engine inlet?
Disturbed airflow which reduces performance
Can damage fan blades or inlet vanes
Turboprops use what to provide anti icing?
Warm oil from engine oil reservoir
Most common type of engine ice protection systems are known as what?
Thermal systems
Thermal systems are subdivided into what?
Bleed air
Electrical heating
On smaller turboprop and turbo shaft engines what anti ice system do they use?
Electric heat strip systems
Is the air inlet duct considered a part of the air frame?
Yes
Describe a divergent duct?
Velocity- Decreases
Pressure- Increases
Temperature- Increases
Describe a convergent duct?
Velocity- Increasing
Pressure- Decreasing
Temperature- Decreasing
