Importing OrcaFlex Models

SIMA can read an OrcaFlex model file (.yml) and build an equivalent coupled RIFLEX/SIMO task. Slender lines, vessels, buoys, moorings, wind turbines, and the environment are all imported.

The importer does not reproduce every OrcaFlex feature. It aims to cover any OrcaFlex data where equivalent functionality is available in SIMA. Data that SIMA has no equivalent for is left out. In most cases the importer adds a warning to the import log. It is highly recommended to review the log after importing.

The OrcaFlex importer is under active development (preview). It does not reproduce every OrcaFlex feature, and coverage is still being expanded. An imported model is a starting point: it typically needs manual adjustment before it runs, and results should not be trusted until the model has been reviewed and validated against the original. Always read the import log, and check the model against the group coverage and limitations below. Use with care in production work.

1. What imports today

The model types SIMA users most often start from import end to end:

  • Mooring and catenary systems (anchors, chains, fairleads).

  • Flexible risers and slender-line systems, imported as coupled RIFLEX lines.

  • Vessels and 6D/3D buoys, imported as SIMO bodies, structural super-nodes, or nodal bodies according to their role in the model.

  • Wind turbines (turbine, blade topology, airfoil polars, and the supporting tower).

  • Links and winches, imported as SIMA couplings.

  • Multibody radiation coupling (partial, see the coverage table).

2. Group coverage

OrcaFlex organises a model into top-level groups (Environment, Lines, Vessels, and so on). The table below gives the import status of each group. It is a group-level summary. Individual fields within an Imported group may still be skipped, in which case the importer warns at import time.

Status meanings:

  • Imported: the group has a reader. Any missing fields are reported as warnings.

  • Partial: the common case is imported. Some sub-features are not, as noted.

  • Planned: not imported yet. Planned for a future release.

  • Needs SIMA support: not imported. SIMA has no equivalent concept.

  • Ignored: nothing to import. The group holds GUI or metadata only, or is resolved while reading the file.

OrcaFlex group Status Notes

General

Imported

Unit factors and dynamic-calculation parameters. Stage/statics/solver controls planned.

Environment

Imported

Water depth, location, and the primary wave, current and wind. Secondary wave trains and seabed detail planned.

VesselTypes

Imported

RAOs, added mass/damping, wind and current. Wave drift via Newman’s approximation only. Second-order QTFs are not imported.

Vessels

Imported

Instance-level vessel data. Pipelay-support attachment needs SIMA support.

3DBuoys

Imported

3-DOF buoys.

6DBuoys

Imported

6-DOF buoys, structural nodes or nodal masses by role. Support fields need SIMA support.

LineTypes

Imported

Cross sections. Tapered (variable-diameter) pipes are discretised into per-segment sections.

Lines

Imported

Coupled RIFLEX lines with segment geometry, connections and seabed friction.

ClumpTypes

Imported

Clump masses on line nodes.

MorisonElementTypes

Imported

Morison hydrodynamic coefficients (consumed via vessels).

Turbines

Imported

Wind turbine with blade topology and hub body.

WingTypes

Imported

Airfoil lift/drag/moment polars (outline geometry is synthesised for visualisation).

StiffenerTypes

Imported

Bend stiffeners as combined-EI cross sections (bending only). Drag shielding planned.

RayleighDampingCoefficients

Imported

"Coefficients (separated)" mode. Other modes planned. Unresolved references warn.

Links

Imported

Tethers / spring-dampers as couplings.

Winches

Imported

Winch geometry and control as couplings.

VariableData

Imported

Parametric values resolved while reading the file and substituted into the data that feeds every importer.

Constraints

Partial

DOF flags and connection-chain resolution. Per-DOF stiffness/damping needs SIMA support.

Shapes

Partial

Block / Cylinder / Curved-plate geometry. Elastic-solid contact and trapped water need SIMA support.

LineContactData

Partial

Pipe-in-pipe (inside / around) contact. External contact and discrete penetrators not mapped.

MultibodyGroups

Planned

Cross-body radiation coupling. SIMA has the target model, but the importer does not yet populate it.

P-yModels

Planned

Soil P-y curves. SIMA represents these via its PISA soil models.

CodeChecks

Planned

DNV/API code-check factors. SIMA has a code-check post-processor to map onto.

SHEAR7Data

Planned

VIV configuration. Maps to SIMA’s VIVANA engine (cross-engine, non-1:1).

FrictionCoefficients

Needs SIMA support

Friction on shape/support contacts (line-to-seabed friction is unaffected and is imported).

ExpansionTables

Needs SIMA support

Pressure/temperature pipeline expansion grids. No SIMA target.

SupportTypes

Needs SIMA support

Pipelay rollers/bearings/stinger supports. SIMA has no contact-surface support primitive.

UserDefinedResults

Needs SIMA support

OrcaFlex custom-result scripting. No SIMA equivalent (post-processing scope).

Groups

Ignored

OrcaFlex GUI folder hierarchy. No physical data.

3. Limitations

Some effects are dropped on import. Do not assume that data you cannot see in SIMA was imported. Check the import log.

The following are not transferred. Second-order wave loads (sum- and difference-frequency QTFs), elastic shape-contact stiffness, trapped-water regions, friction on shape and support contacts, per-DOF constraint stiffness and damping, VIV and SHEAR7 configuration, pressure and temperature pipeline expansion, and pipelay supports (rollers, bearings, stingers). Most dropped items are reported as a warning during import.

4. Ignored groups

Some OrcaFlex groups hold no model data and are not imported. These are the GUI folder hierarchy (Groups) and post-processing definitions such as UserDefinedResults and CodeChecks. Nothing of value is lost.