11.1 High Speed Intakes Flashcards
What needs to happen to supersonic air when it reaches the engine intake?
Needs to be slowed down to subsonic speeds and with the least possible waste of energy
What must be done to engine inlets on supersonic aircraft
They must be modified
What does a normal shock diffuser inlet do
Creates a normal shock in front of the inlet to slow the air to subsonic speeds
What is a disadvantage of normal shock diffuser inlets
They are extraordinarily strong and cause a great reduction in total pressure recovered by inlet
What happens to supersonic air in a converging inlet
Decreasing velocity and increasing pressure
What happens to supersonic air that’s diverging
Increasing velocity and decreasing pressure
What happens to subsonic air in a converging inlet
Increasing velocity and decreasing pressure
What happens to subsonic air in a diverging inlet
Decreasing velocity and increasing pressure
What does a single oblique shock inlet do
Creates a weak oblique shock wave to slow down air then a normal shock wave to slow it down fully
What does a multiple oblique shock inlet do
Creates multiple oblique shockwaves to slow air before a normal shock wave
What is a Variable supersonic inlet
Optimum shape of supersonic inlet varies with inlet direction and it changes with speed, at Mach 1 it is full open but closes to create more oblique shockwaves as speed increases
