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Aircraft Propellers Notes

AIRCRAFT PROPELLERS (A)

1 - Purpose of a Propeller

  • The primary purpose of a propeller is to convert engine horsepower into thrust.

2 - Thrust Production

  • Thrust is produced by a rotating propeller in the same way lift is produced by a wing.
  • Aerodynamic forces create an area of decreased pressure immediately in front of the propeller.
  • The propeller moves into this area of low pressure, generating thrust.

3 - Aircraft Engine Propulsion

  • The basic difference in thrust production between a turbojet/turbofan and a turboprop engine lies in the mass of air moved and the acceleration imparted to it.
  • An engine-driven propeller imparts a relatively small amount of acceleration to a large mass of air.