Input:

Description

Blade Precone Angle:

The angle in degrees between a flat rotor disk and the cone swept by the blades, positive downwind. Upwind turbines have a negative precone angle for improved tower clearance. This is illustrated by 'Precone' in Turbine Geometry and subsequent schematics.

Blade Pitch Angle:

The blade pitch angle in degrees, positive to feather, leading edge upwind. The axis of rotation is illustrated by 'Blade-Pitch Axis' in Turbine Geometry, while the angle convention is illustrated by 'm: Pitching' in Blade Local Coordinate System.

Input:

Description

Hub Radius:

The radius to the blade root from the center-of-rotation along the (possibly preconed) blade-pitch axis. This is illustrated by 'HubRad' in Turbine Geometry and subsequent schematics.  

Hub Mass:

The mass of the hub.

Input:

Description

Rotor Speed:

The fixed rotor speed (positive clockwise looking downwind).

Shaft Tilt:

The angle in degrees between the rotor shaft and the horizontal plane. A positive shaft tilt angle means that the downwind end of the shaft is the highest. Upwind turbines have a negative shaft tilt angle for improved tower clearance. This is illustrated by 'ShftTilt' in Turbine Geometry and subsequent schematics.

Rotor Overhang:

The distance along the (possibly tilted) rotor shaft between the tower centerline and hub center, measured positive downwind. Upwind rotors have a negative overhang. This is illustrated by 'Overhang' in Turbine Geometry and subsequent schematics.

Rotor Shaft to Tower Distance:

This is the vertical distance from the top of the tower and yaw bearing to the intersection of the rotor shaft axis and the lateral plane (i.e. plane perpendicular to wind direction). The distance is measured parallel to the vertical (tower) axis. This is illustrated by 'Twr2Shft' in Conventional Upwind Turbine Layout.

Rotor Inertia:

Rotational inertia of the rotors about the low-speed shaft which is , the integral of the rotor (blades + hub + low-speed shaft) mass by the distance from the axis of rotation.

Input:

Description

Nacelle Mass:

The mass of the nacelle.  

Nacelle Yaw Bearing Mass:

The mass of the nacelle yaw bearing.

Nacelle Yaw:

This is fixed nacelle yaw angle. It is positive counterclockwise when looking down on the turbine.

Tower Top to Nacelle Centre of Mass (Downwind):

This is the downwind distance to the nacelle mass center from the top of the tower, measured parallel to the xn-axis. It is positive downwind. This is illustrated by 'NacCMxn' in Conventional Upwind Turbine Layout.  Refer to Nacelle/Yaw Coordinate System for an illustration of the local axes.

Tower Top to Nacelle Centre of Mass (Lateral):

This is the lateral distance to the nacelle mass center from the top of the tower, measured parallel to the yn-axis. It is positive to the left when looking downwind or positive into the page of Conventional Upwind Turbine Layout. Refer to Nacelle/Yaw Coordinate System for an illustration of the local axes.

Tower Top to Nacelle Centre of Mass (Vertical):

This is the vertical distance to the nacelle mass center from the top of the tower, measured parallel to the zn-axis. It is positive upward when looking downwind. This is illustrated by 'NacCMzn' in Conventional Upwind Turbine Layout. Refer to Nacelle/Yaw Coordinate System for an illustration of the local axes.

Input:

Description

Gearbox Ratio:

This is the ratio of the high-speed shaft to the low-speed shaft. This value should be greater than zero and equal to unity for a direct-drive turbine.

Input:

Description

ServoDyn Input:

Path to the ServoDyn input file which must contain the Bladed-style dynamic link library (dll) name for implementing turbine control. See Note (a).