15.17 Flashcards
What is a turbo shaft engine used for?
To drive machinery instead of producing thrust
What are common applications for turbsohaft engines?
APU, small lightweight engines, helicopters
Is the output shaft coupled directly to the engine turbine, or have a turbine of its own?
Both
What is a free turbine?
A shaft that is driven by its own turbine that rotates independently
What is the turbines output measured in?
Horsepower
What are the two things that make up a turbo shaft engine?
Gas generator and power section
How does the gas generator drive the power section?
By hot expanded gases
Where are turboshaft required to be used?
High power output, small and lightweight
Where is the reduction of engine RPM done in a turboshaft engine?
At the rear where where the power turbine drives the reduction gearbox and in tern drives the main accessory gearbox
Where is the reduction of engine RPM done in a turboshaft engine?
At the rear where where the power turbine drives the reduction gearbox and in tern drives the main accessory gearbox
What is the purpose of the drive system?
To transfer the power produced in the engine to the componente it drives
What is the purpose of the drive system?
To transfer the power produced in the engine to the components it drives
Due to high rotational speeds, what must be done to the rpm?
Reduced in the reduction gearbox then reduced further via the coupling shaft to the main rotor gearbox
In the Pratt and Whitney engine, there is two engines connected to a common gearbox. What is a freewheel unit used for?
To automatically disconnecf the slower engine
What is the freewheel unit made from?
A sprag clutch
