Exhaust Systems Flashcards
(29 cards)
What is the purpose of the exhaust system?
Capture the exhaust gases and direct it out of the engine.
What is exhaust back pressure?
Opposes the flow of exhaust gases as they are forced out of the cylinders when the exhaust valve is open
What are the different types of exhaust stacks?
Short stacks
Bayonet stacks
What is a collector system?
Am exhaust system that collects gases from all cylinders and discharges them from one location
What is a crossover system?
The left and right exhaust systems are connected together
What are some uses of exhaust heat energy?
Cabin heat
Carb heat
What are some purposes of a muffler?
Absorbs the sound
Directs the gases out of the tail pipe
Can provide provisions for carb and cabin heat
What is the purpose of augmentor tubes?
Uses some of the velocity energy of the exhaust gases to increase the cooling airflow through the engine, decreases exhaust back pressure
How does an augmentor tube work?
Its a convergent shape
creates low pressure
draws cooling air into the cowling and through cylinder fins
Reduces the exhaust back pressure
What are two ways to recover some power?
Turbochargers
Power recovery turbines
What material are exhaust systems normally made out of?
Stainless steel
Inconel
Why are cracks common in exhaust systems?
Vibrations and sudden temperature changes
Why are CO detectors required on aircraft?
CO could leak into the the cabin or flight deck
What should not be used to mark on exhaust systems?
Pencils
What should be done with exhaust systems prior to inspection?
Remove all heater muffs and shrouds
Pure turbo jets work on _____ rather than ______?
Reaction
Aerodynamics
What is the purpose of the exhaust on a turbine engine?
To straightening and accelerate the airflow
What shape of the tail pipe on a subsonic aircraft?
Convergent duct
What is the purpose of the exhaust cone?
To straighten and collect the exhaust gases into a solid high velocity exhaust jet
What is a choked exhaust nozzle?
If the convergent exhaust nozzle increases the velocity of the exhaust gases to Mach 1 they cannot be accelerated any further.
Purpose of a CD exhaust nozzle?
To increase the thrust produced by an engine by accelerating the exhaust gases to a high supersonic speed.
How do noise suppressors work?
They increase the frequency which reduces the distance the noise travels
Why do turbofan engines not normally require noise suppressors?
Extract more energy to drive the fan from the exhaust gases compared to turbojets
Exhaust velocities are lower
By-pass air provides a seal around the high velocity gases to reduce the sound
How do propeller planes slow down?
Reverse pitch
