15.2 Inlet Flashcards
(16 cards)
How is an inlet designed
To provide distortion free airflow to the compressor using inlet guide vanes (IGV)
What are the properties of a divergent duct
Volume decrease
Pressure increase
Temperature increase
What are the properties of a convergent duct
Velocity increase
Pressure decrease
Temperature decrease
How does supersonic flight affect divergent and convergent properties
It inverses the affects
What do turboprop and turboshaft inlet screens prevent
FOD (foreign object debris)
Why is ram recovery introduced
To compensate for losses due to increase in speed to recover as much total pressure of free stream air
What a/c would you find divided ducts on
High speed military a/c
What’s a disadvantage to divided ducts
Moneuvers can cause airflow imbalance
Why is a variable geometry ducts used
To reduce airflow below Mach 1
What are three methods to diffuse the inlet air
Vary the area or geometry
Bypass arrangement
Shockwave
When is a bell mouth inlet installed
During testing
How is the inlet on turboprops anti iced
Electrical elements in the lip of the intake or warm oil from engine resiviour
How is the turbofan inlet lip anti iced
Warm engine bleed air is circulated round the inside
When can ice form when engines are running high speed on the ground
5°C in dry air, 7°C in moist air
Where is hot air bled from for anti icing
HP compressor
When can eclectic heat strip be used for anti icing
When the engines are running
