Table of Contents

Positioning the Hub Centre

The position of the hub centre is specified using the PositionOfHubCentre property. This will place the hub centre in relation to the body-fixed frame of the DrivetrainAndNacelle component. The the body-fixed frame is denoted \((x_{b}, y_{b}, z_{b})\) and the distal frame of the hub centre is denoted \((x_{d}, y_{d}, z_{d})\) in Figure 1.

Figure 1

Figure 1: Diagram illustrating the drivetrain and the properties of PositionOfHubCentre. The left side of the figure illustrates a side view of the DrivetrainAndNacelle and the right side shows a top view. Shown for an upwind configured turbine.

The PositionOfHubCentre has the following properties:

  • RotorTilt: The angle of the low-speed shaft to the horizontal. A positive value will tilt the rotor upwards to face the sky. Denoted \(\theta\) in Figure 1.
  • Overhang: The distance of the hub centre in the negative \(x_b\)-direction from the DrivetrainAndNacelle's origin (where the nacelle is attached to the yaw system or support structure). Denoted \(D\) in Figure 1.
  • HeightOffset: The distance in the DrivetrainAndNacelle's \(z_b\)-direction between the DrivetrainAndNacelle's origin (where the nacelle is attached to the yaw system or support structure) and the hub centre. Denoted \(H\) in Figure 1.
  • SideOffset: The distance in the DrivetrainAndNacelle's \(y_b\)-direction between the DrivetrainAndNacelle's origin (where the nacelle is attached to the yaw system or support structure) and the hub centre. This is often zero or very small. Denoted \(L\) in Figure 1.
Note

The Overhang is defined as a positive value in the negative \(x_b\) on Figure 1.

JSON example of a PositionOfHubCentre object:

"PositionOfHubCentre": {
    "RotorTilt": 0.0698,
    "Overhang": 3.7,
    "HeightOffset": 1.5,
    "SideOffset": 0.0
}