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Table of Contents

Defining the Rotor

Click the Rotor icon on the toolbar to define the basic characteristics of the turbine rotor and hub. The following data must be defined:

  • Rotor diameter

  • Number of blades

  • Hub vertical offset: the vertical distance from the yaw bearing to the hub.

  • Blade set angle: the angle at which the blade is mounted onto the hub. More positive values of set angle push the leading edge further upstream. It is usually convenient to define the set angle as zero, but particularly for stall regulated machines, the set angle provides a simple way of rotating the whole blade (both pitching and non-pitching sections) without having to re-define the twist distribution.

  • Cone angle: the angle between the blade axis and the rotor plane.

  • Tilt angle: the angle between the shaft and the horizontal (normally positive).

  • Overhang: the horizontal distance between the rotor centre and the tower centreline.

  • Lateral offset: the horizontal offset between the shaft and tower axes.

  • Rotational sense: the turbine may rotate clockwise or anticlockwise when viewed from upstream.

  • Position: the rotor may be upwind or downwind of the tower in normal operation.

  • Speed type: the turbine may be defined as a fixed or a variable speed turbine. See also Generator, Control.

  • Control surfaces: Specifies whether the blade is fixed, pitchable (includes full or partial span pitch) or aileron controlled (includes any type of flap or airbrake).

  • Transmission: select Gearbox or Direct Drive. For a direct drive system, either set the gearbox ratio to 1, or select the Direct Drive option here. If the Direct Drive option is selected, the generator mass can be separately identified on the Hub screen, otherwise it must be included in the Nacelle mass.

  • Cut-in wind speed: the steady wind speed at which the turbine is brought on or off line in low wind speeds.

  • Cut-out wind speed: the steady wind speed at which the turbine is brought on or off line in high wind speeds.

Clicking the Hub tab allows the hub configuration to be defined, together with generator mass information if the Direct Drive option is selected. This is described in hub section.

Note

Mass totals: Note that the moment of inertia of the turbine rotor is defined by the blade mass distribution and the hub inertia.

Last updated 05-12-2024