M15.16 Flashcards
What is the speed range for gas turbine engines and reduction gearbox coupled propeller to be most efficient at?
483-725km/h or 300-450mph
What is the height for gas turbine engines and reduction gearbox coupled propeller to be most efficient at?
6,000m or 20,000 feet above sea level
How much percentage of the total power goes into driving the propeller, gearbox, compressor, accessories?
Up to 95%
In a turbo-prop what is the core also known as?
The gas generator or gas producer
What is special about the gas coupled/ free power turbine engine?
There is no mechanical connection between the gas generator and the free power turbine
What is special about about the gear/ direct coupled turbines engine?
It has extra turbine discs which stay connected
What is used to prevent ingress of FOD on a turbo-prop?
Particle separators
How does a moveable vane work inside a particle separator?
It extends to increase the velocity of the airflow
What must reduction gear systems have?
A much higher reduction ratio that those fitted to the piston engine
How are reduction gearboxes lubricated?
From the engine lubrication system or its own self-contained system
If a turbo-prop engine uses spur gears what will it need?
Very large reduction gear ratios
Why is a bevel epicyclic gear only used in turbo-prop engines?
Because of the weight and dimensions
Why are helical gears used?
Because they reduce noise and vibration
What direction does a rotating annulus rotate?
The opposite direction of engine rotation
What direction does a fixed annulus rotate?
The same direction as the engine rotation
