Turbine Engines Flashcards
Explain the main difference and advantage of turbofan over turbojet engines.
A turbofan engine uses a fan to bypass some air around the engine core and to provide thrust. The advantage is that this provides additional thrust without increasing fuel flow.
Name the major components in a gas turbine engine.
Air inlet, the compressor section, turbine section, exhaust section, gearbox, and accessory section.
What determines the amount of airflow through a turbine engine?
The forward speed of the aircraft, compressor speed, and air density.
Name the two types of compressors commonly used in turbine engines.
Axial and centrifugal flow.
Name the two different methods for attaching turbine engine rotor blades to the rotor disks.
Dovetail root, bulb root, or fir tree root.
What is a split compressor system?
Also called dual or twin spool compressors, these are connected to the turbine section with two rotor shafts, one inside the other.
What are the different types of combustion chambers used in turbine engines?
Can, annular, and can-annular.
What prevents the combustion chambers from burning?
Cooling air along the inside of the liner.
What is the purpose of the interconnecting tubes attached between can type combustion chambers?
For flame propagation during start.
What function do axial flow turbine nozzles perform?
They direct the mass airflow to drive the turbine rotor at a specific angle.
How is thermal stress relieved on a turbine disc?
By directing bleed air onto the face of the disk, or by grooves being cut into the disk.
What are carbon seals used for in turbine engines?
They are used as oil seals for the rotor shaft bearings.
What is shaft horsepower?
It is an indication of the torque being developed by a turboprop or turboshaft engine.
Name the main components of a typical APU.
A small power turbine for power and bleed air, and an electrical generator.
When is the greatest demand placed on an APU?
When supplying bleed air.
