Support Vessel

A support vessel defines the position, orientation, and motion of a vessel to which slender structure lines are attached. It provides the motion transfer function used to apply vessel motions as boundary conditions on the line end nodes during dynamic analysis.

The vessel is positioned in the global coordinate system and assigned a motion transfer function that relates wave-frequency vessel motions to the wave field.

Multiple support vessels can be defined in a single model. Each vessel can be associated with one or more line ends, allowing for different vessel motions to be applied to different lines in the system.

The vessel motion is applied as a boundary condition on the line end nodes during dynamic analysis, influencing the dynamic response of the attached lines.

For description of transfer function file format, see Support Vessel Data - File Format.

1. Parameters

1.1. Vessel initial position

  • X, Y, Z: Position of the vessel coordinate system origin in the global system (meters)

  • Rz: Heading of the vessel, rotation about global z-axis (degrees from global X-axis)

1.1.1. Geometry

  • Type: The support vessel can be represented by different geometry types, options are:

    • Default arrow box: default box geometry with an arrow indicating the forward direction of the vessel. This is a simple representation suitable for small vessels or when the vessel’s shape is not critical to the analysis.

    • Geometry file: Geometry is defined by an external file containing the coordinates of the vessel’s surface points. This allows for detailed and complex vessel shapes to be modeled.

      • Translation, rotation and scaling can be specified for the geometry file to position and orient the vessel in the model.

      • File format are *.obj, *.stl, *.gdf or *.fem

    • Box: The vessel is represented as a rectangular box defined by its length, width, and height and location relative for the vessel initial position.

    • Sphere: The vessel is represented as a sphere defined by its radius and location relative for the vessel initial position.

    • Cylinder X, Cylinder Y, Cylinder Z: The vessel is represented as a cylinder defined by its diameter and height and and location relative for the vessel initial position.

    • No graphical representation: The vessel is not represented graphically in the model.

  • Transparency: Transparency of the vessel geometry in the graphical user interface, specified as a value between 0 and 1 (0% is fully opaque, 1 is fully transparent).