Marine systems simulation
Net structure with wake

Class containing a net object.

+ Collaboration diagram for Net structure with wake:
Author
Karl-Johan Reite
Todo:
Finish documentation and make complete example file.

Example configuration excerpt

<Lib
LibName = "marine_elements"
SimObject = "Net/NetStructure"
Name = "NET"
UseTagForExternalNodes = "true"
AddedDragPerMPS = "0"
File = "NetStructureInput.xml"
WakeEffectBetweenElementsOn = "false"
WakeEffectBetweenTwinesInElementsOn = "false"
UseActualElementSizeInWakeEffect = "true"
NumBarsInWakeEffectCalc = "100"
UseReynoldsDependentDragCoefficient = "false"
UseScreenModelForHydrodynamicForce = "false"
UseDragCoeffFromMoeFore2021 = "false"
SnFromImageAnalysis = "0.4"
RhoWater = "1025"
NetTotalForceCheck = "0,0,0"
/>

Example NetStructure configuration file

The simobjects input-file takes an argument File (or BinaryFile), which specifies a path to a file. This file contains parameters general to the Net Structure component, and specific to the cable objects.

<Net>
<General
MaxNumPanels = "100"
MaxNumCables = "100"
MaxNumNodes = "6"
MinElementLength = "1"
MaxElementLengthFactor = "1025"
MaxStepLength = "1"
MaxTension = "1e-10"
MeanTension = "1e10"
MinLength = "0"
StepSafetyFactor = "50"
AdaptationPeriod = "0"
MassFactor = "1"
MaxAcceleration = "1e20"
MaxVelocity = "0"
Scale = "1"
FoldingPointRefinement = "0"
TwineColour = "1,1,1,1"
/>
<ExternalNodeMap
NodesInputForce = "0,0,0"
NodesOutputPosAndVel = "0,0,0"
</
<NetElements
Name = "7"
Conn = "0,0,0,0"
PosAMesh = "0,0"
PosBMesh = "0,0"
PosCMesh = "0,0"
PosDMesh = "0,0"
BarD = "0"
BarL = "0"
BarE = "0"
BarRho = "0"
Refinefactor = "1"
TwineColour = "1,1,1,1"
/>
<CableElements
Conn = "0,0,0,0"
Name = "???"
D = "0"
L = "0"
E = "0"
Rho = "0"
RefineFactor = "1"
MaxTension = "100e4"
MaxStep = "1000"
MeanTension = "0"
MinLength = "0.001"
StepSafetyFactor = "50"
AdaptationPeriod = "0"
NoOfFoldingPoints = "0"
TangentialFrictionCoeff = "0.03"
NormalDragCoeff = "1.2"
Material = "Trawl/Wire2"
DrawScale = "1.0"
NumFaces = "5"
NumSpheres = "5"
SphereD = "0.05"
SphereMass = "10"
SpherePos = "0,0,0"
NumDisks = "2"
DiskD = "0.1"
DiskThickness = "0.001"
DiskMass = "10"
DiskPos = "1,0,0"
/>
</Net>

Input Ports

Name Width Description
<???>Force...<???>Force 3 Only if external node tags are used ...
ExternalForce<???>...ExternalForce<???> 3 Only if external node tags are NOT used ...

Output Ports

Name Width Description
<???>Force...<???>Force 3 Only if external node tags are used ...
<???>ExternalForce...<???>ExternalForce 3 Only if external node tags are NOT used ...
<???>Pos...<???>Pos 3 Only if external node tags are used...
<???>ExternalPos...<???>ExternalPos 3 Only if external node tags are NOT used ...
<???>Vel...<???>Vel 3 Only if external node tags are used ...
<???>ExternalVel...<???>ExternalVel 3 Only if external node tags are NOT used ...
BottomContact 6 ???
VelNorm 1 ???
StrainEnergy 1 ???

Configuration parameters in the main input file to the NetStructure-simObject

Name Width Description
??? ??? ???

Configuration parameters in the General-tag of the input file in the Net-tag.

Name Width Description
??? ??? ???

Configuration parameters in the ExternalNodeMap-tag of the input file in the Net-tag.

Name Width Description
??? ??? ???

Configuration parameters in the NetElements-tag of the input file in the Net-tag.

Name Width Description
??? ??? ???

Configuration parameters in the CableElements-tag of the input file in the Net-tag.

Name Width Description
??? ??? ???

Initial conditions

Name Width Description
Pos_1...Pos_<???> 3 ???
Vel_1...Vel_<???> 3 ???

Full example file

Todo:
Add complete example file.

This SimObject is referred to as Net/NetStructureWakeEffect