Specifying the Disk Orientation

In addition to the geometric dimensions and the origin of the virtual disk, specify its orientation.

The way that the virtual disk is oriented—that is, in which direction the z-axis of the local disk coordinate system points—is the direction in which the virtual disk produces thrust. The positive z-axis points in the direction in which the disk would move if let free.

Before you begin to set the orientation of the virtual disk, it can be helpful to visualize the local disk coordinate system.

To visualize the local virtual disk coordinate system:

  1. Open a scene, for example a geometry scene.

For more details, see Creating a Scene.

  1. Click the scene/plot button.
  2. In the scene node, for example the [Geometry Scene 1] node, click the (custom editor) next to the Coordinate Systems property and set this to Laboratory > Local Coordinate Systems > [Virtual Disk-CSys 1].
  3. In the object selection dialog, select [Virtual Disk-CSys 1] and click OK.

    The current orientation of the local coordinate system of the virtual disk will be visible in the Graphics window of the currently open scene.

You have two options available to specify the disk orientation:

  • Disk orientation in terms of disk normal and coordinate system
  • Disk orientation in terms of lateral and pitch angle

To specify the disk orientation in terms of disk normal and coordinate system:

  1. Select the Disk Geometry node and set the Orientation Specification to Disk Normal and Coordinate.
  2. Select the Disk Geometry > Normal and Coordinate System node.
  3. In the Normal And Coordinate System - Properties window, set the following properties:

    Coordinate System

    Specify the coordinate system in regard to which the normal of the virtual disk is defined. You can also use a user-defined local cartesian coordinate system to define the disk normal.

    Disk Normal

    Specify the direction that is normal to the plane of the disk.

To specify the disk orientation in terms of disk lateral and pitch angle:

  1. Select the Disk Geometry node and set the Orientation Specification to Pitch Angle and Lateral Angle.
  2. Select the Disk Geometry > Lateral And Pitch Angle node.
  3. In the Lateral and Pitch Angle - Properties window, set the following properties:

    Pitch Angle

    To rotate the local disk coordinate system, you specify a pitch angle. The pitch angle rotates the x-z plane around the y-axis.

    Lateral Angle

    To rotate the local disk coordinate system, you specify a lateral angle. The lateral angle rotates the y-z plane around the x-axis.