Compressors Flashcards
What are mid-span shrouds used on fan blades?
To dampen any fluttering
Why are mid-span shrouds given a special coating?
To prevent rubbing between the shrouds that could cause damage
What is the purpose of the Kevlar wrap?
To contain the fan blades
What is another method of containing the fan blades?
Extra thick casing
Where would the moment weight be found on the fan blades?
Blade root
Where are the abradeable shrouds found on a fan module?
Inner surface of fan case
What effect do stator vanes have on air flowing through the compressor?
Guide and slow down the air
What effect does the last set of stator vanes have on the air going into the combustion chamber?
Slow and straighten the airflow for the entering the combustion chamber
What effect will increasing the airflow velocity have on the angle of attack of a blade?
The velocity will drop but the angle of attack will increase
What is a compressor stall?
When the airflow separates in the compressor, sometimes even reversing the direction of the airflow
One stage
What is a compressor surge?
A very severe stall
All stages
What methods can be employed to reduce or prevent stalls or surges?
Compressor bleed valves
Dual or triple spool rotors
Variable compressor stator vanes
What is the maximum number of stages on a centrifugal compressor engine?
2
What is the make up of a compressor stage?
Rotor and stator
How are modern compressors built up?
Combustion case and outlet case, or the two combined
