Mooring¶
The mooring system ontology follows closely the input file format for MoorDyn or MAP++. Additional information can be found in the MoorDyn user guide .
nodes:
- name: line1_anchor
node_type: fixed
joint: anchor1
anchor_type: drag_embedment
- name: line2_anchor
node_type: fixed
joint: anchor2
anchor_type: drag_embedment
- name: line3_anchor
node_type: fixed
joint: anchor3
anchor_type: drag_embedment
- name: line1_vessel
node_type: vessel
joint: col1_fairlead
fairlead_type: rigid
- name: line2_vessel
node_type: vessel
joint: col2_fairlead
fairlead_type: rigid
- name: line3_vessel
joint: col3_fairlead
node_type: vessel
fairlead_type: rigid
lines:
- name: line1
node1: line1_anchor
node2: line1_vessel
line_type: main
unstretched_length: 850.0
- name: line2
node1: line2_anchor
node2: line2_vessel
line_type: main
unstretched_length: 850.0
- name: line3
node1: line3_anchor
node2: line3_vessel
line_type: main
unstretched_length: 850.0
line_types:
- name: main
diameter: 0.185
type: chain
transverse_added_mass: 1.0
tangential_added_mass: 0.0
transverse_drag: 1.6
tangential_drag: 0.1
anchor_types:
- name: drag_embedment
type: drag_embedment
nodes¶
name
StringName or ID of this node for use in line segment
node_type
: String from, [‘fixed’, ‘connection’, ‘vessel’]
location
Array of Floats, meter– Coordinates x, y, and z of the connection (relative to inertial reference frame if Fixed or Connect, relative to platform reference frame if Vessel). In the case of Connect nodes, it is simply an initial guess for position before MoorDyn calculates the equilibrium initial position.
anchor_type
StringName of anchor type from anchor_type list
fairlead_type
: String from, [‘rigid’, ‘actuated’, ‘ball’]
node_mass
Float, kilogramClump weight mass
Minimum = 0.0
node_volume
Float, meter^3Floater volume
Minimum = 0.0
drag_area
Float, meter^2Product of drag coefficient and projected area (assumed constant in all directions) to calculate a drag force for the node
Minimum = 0.0
added_mass
FloatAdded mass coefficient used along with node volume to calculate added mass on node
lines¶
name
StringID of this line
line_type
StringReference to line type database
unstretched_length
Float, meterlength of line segment prior to tensioning
Minimum = 0.0
node1
Stringnode id of first line connection
node2
Stringnode id of second line connection
line_types¶
name
StringName of material or line type to be referenced by line segments
diameter
Float, meterthe volume-equivalent diameter of the line – the diameter of a cylinder having the same displacement per unit length
Minimum = 0.0
mass_density
Float, kilogram/metermass per unit length (in air)
Minimum = 0.0
stiffness
Float, Newtonaxial line stiffness, product of elasticity modulus and cross- sectional area
Minimum = 0.0
cost
Float, USD/metercost per unit length
Minimum = 0.0
breaking_load
Float, Newtonline break tension
Minimum = 0.0
damping
Float, Newton * secondinternal damping (BA)
transverse_added_mass
Floattransverse added mass coefficient (with respect to line displacement)
Minimum = 0.0
tangential_added_mass
Floattangential added mass coefficient (with respect to line displacement)
Minimum = 0.0
transverse_drag
Floattransverse drag coefficient (with respect to frontal area, d*l)
Minimum = 0.0
tangential_drag
Floattangential drag coefficient (with respect to surface area, π*d*l)
Minimum = 0.0
anchor_types¶
name
StringName of anchor to be referenced by anchor_id in Nodes section
mass
Float, kilogrammass of the anchor
Minimum = 0.0
cost
Float, USDcost of the anchor
Minimum = 0.0
max_lateral_load
Float, NewtonMaximum lateral load (parallel to the sea floor) that the anchor can support
Minimum = 0.0
max_vertical_load
Float, NewtonMaximum vertical load (perpendicular to the sea floor) that the anchor can support
Minimum = 0.0