15.03 Flashcards
What does air enter the engine via?
Engine air intake
The air inlet get wider, what’s that called?
Divergent duct
For air to flow smoothly through a compressor what should it’s velocity be?
Mach 0.4 - 0.7 at the inlet
The subsonic air inlet must be designed so?
Ram velocity of air is slowly and smoothly decreasing
In a transonic duct what does a normal shock wave produce?
Temperature rise and velocity decrease
In a transonic duct what happens if rpm demand is decreased?
Inlet pressure will rise allowing less air in, excess air will be forced out the inlet
What is the super critical condition?
Airflow demand is greater than the inlet can provide causing a pressure drop and the shockwave to be swallowed
What are the 4 intake designs and their efficiency?
. Pitot 96-99%
• Wing root 87-95%
• Side 80-89%
• Turbo Prop Annular 74-82%
What are the 3 shockwaves at supersonic inlet ducts?
Normal, oblique, bow wave
When does the normal shockwave occur?
Low supersonic speed
What must the air entering the compressor be slowed to?
Subsonic velocity
What are the two negative effects ice has on the engine inlet?
Disturbed airflow, engine suck in ice and damages it
What does the antenna do when it gets ice build up?
Heats up
What can ice protection thermal systems be divided into?
. Bleed air
. Electrical heating
What are the other methods to prevent ice build up on the spinner?
. Hot oil
. Rubber spike
