Structural Design of High-Speed Propellers

VARIOUS structural problems encountered in the design of high-speed turboprop propellers are discussed in this paper.

Formulas for a number of design factors are also given here. These include:

1. 1.
   Blade efficiency.
2. 2.
   Power capacity.
3. 3.
   Advance/diameter ratio.
4. 4.
   Limiting tip speed.
5. 5.
   Periodic lift.
6. 6.
   Propeller normal force and moment.

The paper also describes two types of vibration occurring with turboprop installations:

1. 1.
   First-ordered aerodynamically excited vibration.
2. 2.
   Subsonic stall flutter.

The author shows how these vibrations may be accurately predicted and controlled by proper design of the propeller blades.