15.7 exhaust Flashcards
the exhaust system has several components, what is there one common function they have
to direct the flow of hot gases rearwards to prevent turbulence and, impart a high final or exit velocity to the gases
what does the small hole at the end of the exhaust cone allow
cooling air to be circulated from aft end of the cone into the interior of the cone
`what is primarily used to reduce heat loss from the exhaust system
insulation blanket
what are the two types of exhaust nozzle designs
- the converging type for subsonic gas velocities
- the converging-diverging for supersonic gas velocities
how many nozzles does the unducted fans have
2
where are variable exhaust nozzles fitted
in engines with an afterburner
what can change both the engine performance and the exhaust gas temperature
both can be changed by adjusting the area/diameter of the exhaust nozzle
what are the three sources of noise from an engine
the engine air intake
vibrations from the engine housing
the engine exhaust
what engine creates the most noise
the turbojet engine
the noise from the engine exhaust is caused by what
the high degree of turbulence of a high-velocity jet stream
what are the two typical noise suppressors in current use
corrugated perimeter type
multi-tube type
in the engine nacelle, what is placed between the engine and the cowl
an acoustic lining
when is thrust reversers used
during landing, typically in wet conditions
how does thrust reversers produce braking forces
by deflecting the exhaust gas stream in the opposite direction
what are the different types of thrust reverser
clamshell type
bucket type
fan reverser
pivoting door reverser
what type of thrust reverser do turbofans with a high bypass ratio use
fan reverser
how are pivoting door reversers activated
hydraulically
how are clamshell thrust reversers operated
pneumatically
how are bucket thrust reversers operated
hydraulically
what are fan reversers most commonly
cascade-type thrust reversers
what depend if the cascade-type thrust reversers is hydraulically or pneumatically operated
the type of engine
what are the components of the exhaust section
the exhaust cone, tailpipe and the exhaust nozzle
what is the exhaust cone supported by
the radial struts
how is effective noise reduction for a turbojet aircraft achieved
by changing the noise pattern or the frequency of the noise emitted by the jet nozzle
where is thrust reverse used
ONLY on the ground
