Vessels#
Vessel can be defined using a .csv file (comma separated values) as the example below. For format see file_parser.py
These files can be edited by a spreadsheet-program such as excel. When saving make sure that the proper format is used. Especially the dutch versions may mess things up because there a comma is used in numbers as well.
General properties:
property |
definition |
used for |
|---|---|---|
deck_elevation |
z [m] of deck |
used for placing cargo |
Used for calculating wind and current area |
||
keel_elevation |
z [m] of keel |
Typically 0 |
Used for calculating wind and current area |
||
tank_cut_elevation |
z [m] |
elevation to slice barge to create tank layout. Just 0.5m below the top of the tanks is usually a good idea |
barge_cut_elevations |
z [m] |
elevation(s) to slice the visual of the barge for 2d visuals |
width |
width of the barge [m] |
Drawing the sketch of the deck-layout |
Calculating the wind and current area |
||
length |
length of the barge [m] |
Drawing the sketch of the deck-layout |
Calculating the wind and current area |
||
Cd_air_long |
Cd [-] |
Drag coefficient for wind in longitudinal direction |
Cd_water_long |
Cd [-] |
Drag coefficient for current in longitudinal direction |
Cd_air_trans |
Cd [-] |
Drag coefficient for wind in transverse direction |
Cd_water_trans |
Cd [-] |
Drag coefficient for current in transverse direction |
For typical values for Area based, 3D drag coefficients see: https://en.wikipedia.org/wiki/Drag_coefficient
Calculations#
The wind and current areas of barge are calculated from the user-defined draft as well as the general
properties of the barge.
The part of the hull below the water-surface in even-keel condition is used as current area:
Ac = draft * width (or length)
The part of the hull above the water-surface in even-keel condition is used as wind area:
Aw = (deck_elevation - keel_elevation - draft) * width (or length)
Wind and current forces apply at the center-line or mid-section of the barge.
Note:
The draft used for wind and current is user-defined and is not calculated or updated automatically. This means that actual heel, trim and draft changes of the barge
do not change the wind/current areas. For example in stability calculations the wind-area of the barge does not change.
General section#
# This is a test-file for the P41 barge,
#
# General properties
#
deck_elevation, 4, # elevation of the deck relative to the origin. Typically the distance between keel and deck
keel_elevation, 0, # elevation of the keel relative to the origin. Typically 0
#
# For creating 2D sketches
#
# for creation of the tank plan we slice the 3d model as a fixed elevation.
tank_cut_elevation, 3.9, # elevation to slice barge to create tank layout. Just 0.5m below the top of the tanks is usually a good idea
barge_cut_elevations, 2, 3.9, # elevation(s) to slice the visual of the barge for 2d visuals
# For deck layout we just use a rectangle (not a slice becuase we need to have measurements in the sketch)
width, 17.5, # width of the barge. For sketches of deck-layout
length, 75, # length of the barge. For sketches of deck-layout
# For wind and current force the following coefficients are used: https://en.wikipedia.org/wiki/Drag_coefficient
Cd_air_long, 1.2
Cd_water_long, 1.2
Cd_air_trans, 1.2
Cd_water_trans, 1.2
Ballast tanks#
Ballast-tanks are Tank nodes. They are automatically included in the ballast-system solver. The total volume of the tank is derived from the geometry. Use permeability to tune the capacity.
#
*BallastTanks,
#
# Ballast-tanks are Tank nodes. They are automatically included in the ballast-system solver.
# The total volume of the tank is derived from the geometry. Use permeability to tune the capacity.
#
# Name, resource, permeability,density,Fill-pct, off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z, invert-normals
1C,res: P41/Tanks/1C.obj,1,1,0,0,0,0,90,0,0,1,1,1,false
1PS,res: P41/Tanks/1PS.obj,1,1,0,0,0,0,90,0,0,1,1,1,false
1SB,res: P41/Tanks/1SB.obj,1,1,0,0,0,0,90,0,0,1,1,1,false
2C,res: P41/Tanks/2C.obj,1,1,0,0,0,0,90,0,0,1,1,1,false
Other tanks#
Other tanks are tanks that are not included in the ballast system. The total volume of the tank is derived from the geometry. Use permeability to tune the capacity.
#
*OtherTanks
#
# Other tanks are tanks that are not included in the ballast system.
# The total volume of the tank is derived from the geometry. Use permeability to tune the capacity.
#
# Name, resource, permeability,density,Fill-pct, off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z, invert-normals
#
DieselTank,res: cylinder 1x1x1.obj,1,0.85,70,70,5,4,0,0,0,3,3,3,false
Bollards#
These are the bollards. Capacity [kN] is added as limit to the nodes. A negative capacity means no limit.
#
*Bollards
#
# name,Pos-x,Pos-y,Pos-z,capacity,capcity-x, capcity-y
ps1,10,10,4,100,-1,-1
ps2,20,10,4,100,-1,-1
sb1,10,-10,4,100,-1,-1
sb2,20,-10,4,80,-1,-1
sb7,70,-10,4,80,-1,-1
ps7,70, 10,4,80,-1,-1
Draft measurement points#
define locations at which the draft is measured and reported.
#
*Draft_measurement_points
#
# Define points at keel elevation. Draft is then the current depth of these points
# name, pos-x, pos-y, pos-z
ps_bow, 0, -9, 0
sb_bow, 0, 9, 0
ps_stern, 39, -9, 0
sb_stern, 39, 9, 0
ps_midship, 19.5, -9, 0
sb_midship, 19.5, 9, 0
Buoyancy#
Defines one or more buoyancy shapes
#
*Buoyancy
#
# Name, resource, off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z,invert-normals
Hull,res: P41/p41.obj,0,0,0,90,0,0,1,1,1,false
Visuals#
Defines one or more visuals
#,
*Visuals,
#,
# Name, resource, off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z,
Hull,res: visual.obj,0,0,0,90,0,0,1,1,1,
LightWeight#
This defined the weight and inertia of the barge. Inertia is only used when doing dynamics.
#,
*LightWeight,
#
# This defined the weight and inertia of the barge. Inertia is only used when doing dynamics.
#
#,Footprint,Dynamics,
# Name,mass [mT],Cog-x,Cog-y,Cog-z,Fp-elevation,aft,front,sb,ps,rxx,ryy,rzz,
#,mT,m,m,m,m,m,m,m,m,m,m,m,
front,50,72,0,2.5,2,70,75,-7.9,7.9,3,25,25,
main,1000,37.5,0,2.5,2,5,70,-7.9,7.9,3,2,3,
stern,50,3,0,2.5,2,0,5,-7.9,7.9,3,2,3,
WindAreas#
Optionally add additional wind-areas to the vessel:
*WindAreas
# name ,point x,y,z, area [m2], normal x, y,z, Cd, kind
# kind is either of the following: plane, sphere or cylinder
#
# Location A Normal Cd kind
Area1 164 0 18 384 0 1 0 1.2 plane
Area51 144 0 18 96 0 1 0 1.0 cylinder
Attachments#
See attachments for more information
#
# Attachements
#
# Attachements are defined in two steps
# 1. Attachment types: These define the things that can be attached and gives them a name (WHAT)
# 2. Attachment locations: This defines WHERE the attachements may be attached
#
@ATT: Stability pontoon 15x3x4 # This is the NAME of an attachement type, @ATT: signals that this section is an attachment
class, Component , # This is the node-class. In this case the attachement is a "Component"
path, res: SP/pontoon_15x3x4.dave , # These are properties of the node. All properties are supported.
z, -2.5 , # place the component at z=-2 below the connection point
# , , In this case we set the 'path' property of the component to load the asset
@ATT: Jacket on deck (loose!) # This is the NAME of an attachement type, @ATT: signals that this section is an attachment
class, Component , # This is the node-class. In this case the attachement is a "Component"
path, res: foundation.dave , # These are properties of the node. All properties are supported.
# , , In this case we set the 'path' property of the component to load the asset
#
*Attachments, # We now define the places where the stability pontoon can be placed
#
# Name, Target, posx, posy, posz, rotx, roty, rotz, attachments
Stability pontoon on ps, self , 10 , 9 ,2.5, , 0,0,0, Stability pontoon 15x3x4
Stability pontoon on sb, self , 10 , -9,2.5, 0,0,180, Stability pontoon 15x3x4
On deck , self , 50 , 0,4, 0,0,0, Stability pontoon 15x3x4, Jacket on deck (loose!)