Inlet Configurations Flashcards
Where is a divided entrance duct used?
For high speed and military aircraft
What are the two types of divided entrance duct?
Wing root inlet or scoop on either side of fuselage
What may happen to divided entrance ducts during manouvres?
They may experience a slight loss of power
What do you want from an inlet duct?
As straight as possible with minimal drag
What are inlet ducts designed to act as?
Diffusers that decrease velocity and increase static pressure
Where would a variable geometry duct be used?
At supersonic speeds
Why is a variable geometry duct used opposed to others?
As it allows for varying speeds and adjusts
What are the 3 stages of diffusion in a variable geometry duct?
-vary area/geometry by introducing moveable restrictions such as a ramp or wedge
-variable airflow bypass arrangement extracting part of the inlet airflow from the duct ahead of the engine
-use of a shockwave in the airstream by small deployable shockwave device
What do compressor inlet screens prevent?
The engine ingesting items drawn into the intake
What do compressor inlet screens protect against st?
Internal damage
What can cause a loss on inlet duct pressure?
Compressor inlet screens
What is the risk of a compressor inlet screen if it fails?
It may do more damage than if it had no screen at all
When are compressor inlet screens typically withdrawn?
After take off or whenever icing conditions are encountered
What type of failiure are compressor inlet screens susceptible to?
Mechanical failiure
What are bellmouth compressor inlets normally used for?
Engine testing
What are bellmouth compressor inlets typically equipped with and why?
Probes that when paired with instruments allow measurements of intake temperature and pressure (total and static) to be taken
What are bellmouth compressor inlets designed to obtain?
Very high aerodynamic efficiency
What are bellmouth compressor inlets used for?
Testing
What must be considered for turboprop and turboshaft compressor inlets?
The propeller drive shaft,hub & spinner must be considered along with all other factors
How is the compressor inlet duct anti iced on turboprop and turboshaft engines?
By electrical heating elements on the intake lip
What directs airflow to engine intake on turboprop and turboshaft compressor inlets?
The ducting
What doesn’t allow ice buildup on surface?
Conical spinner
How is a turbofan inlet ant iced?
Pneumatically with bleed air
