Engines Ch5

Describe the basic construction of a turboprop engine.

Gas generator with a reduction gearbox, torquemeter assembly, and a properller assembly.
What component produces the majority of thrust in a turboprop?

Prop (90% of total thrust)
Why are reduction gears required in a turboprop?

To keep the blade tips subsonic. COnverts high RPM / low torque to low RPM/high torque.
How much trust is produced from the exhaust gases of a turboprop?

10%
What are the advantages and disadvantages of a turboprop incomparison with a turbojet?
- +: low TSFC, high thrust at low airspeed, able to carry more load requireing short runways.
- -: heavier and more complicated, limited to 450 knots
How is a turboshaft constructed?

Gas turbine with a free air/power turbine.
What is a free turbine?

A turbine that is not mechanically connected to the compressor and aft of the gas generator turbines.
Describe the sections of a turboshaft and its function.
- Gas gen: provides exhaust gas to drive the free/power turbine.
- Free/power turbine: connceted to the main transmission, it converts the heat energy to mechanical energy to drive the rotors.
What percentage of a turboshaft's thrust comes from the exhaust?

negligible

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beardpapa

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Card Set

Engines Ch5

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Book Questions Chapter 5

Updated

2012-04-24T03:42:20Z