Octo for naval and offshore hydrodynamics

Sea cases, run in batch. The analysis stays yours, signed.

Computational fluid dynamics (CFD), potential theory and mooring and riser analysis programs almost all run without a screen: Java macros in Simcenter STAR-CCM+, text files in OpenFOAM and WAMIT, a Python API in OrcaFlex, the command line in SIMA and Ansys Aqwa. Octo can prepare the case matrix, check the inputs and consolidate the results, all for human review. The one who validates the model is the engineer in charge; the ones who approve are the classification society and the authority.

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Programs surveyed8CFD, potential theory and line dynamics

Run on Linux6 of 8with Linux in the documentation; OrcaFlex requires Windows

WAMIT7.6available since Mar 4, 2026, according to WAMIT

Sources15listed at the end of the page

What Octo does in hydrodynamics.

Six possible deliverables, drawn from the research. All of them start from a base case approved by the engineer and a machine where the software is already licensed; none validates a model, and all of them go to review by a person.

Case matrix

From the base case, it can generate the files or commands for each condition: speed, draft, wave height and period, current, wind and irregular sea seed, with the list recorded in a spreadsheet.

Deliverable: case matrix + input files

Resistance curve in batch

It can prepare one STAR-CCM+ run per speed, with a Java macro, or one OpenFOAM case per speed, keeping the mesh and the stopping criterion.

Deliverable: batch script + speed × resistance table

Mooring and risers in a queue

It can run OrcaFlex .yml models through the Python API (OrcFxAPI) or SIMA tasks through the sre executable, one case per seed, and log what failed without stopping the batch.

Deliverable: batch run + failure log

Input checks

It can compare mass, center of gravity, units, coordinate system and nondimensionalization between programs, for example between the WAMIT output and the OrcaFlex model. The result is a list of discrepancies; the one who decides is the engineer.

Deliverable: list of discrepancies for decision

Consolidated results

It can read WAMIT numeric files (.1, .4), OrcaFlex simulations through the API, SIMA results.h5 and text outputs, and gather everything in one table with the software and model version.

Deliverable: single table + comparison charts

Reproducible log

Proposes a log of the commands, versions and parameters of each run, so the analysis can be repeated and audited by the engineer, the classification society or the client.

Deliverable: processing calculation record

Eight arms, one digital towing tank.

The same Octo cycle, applied to hydrodynamics. Each arm has a narrow role; the ones who validate the model and release the machine are people in your company.

Discovery
Identifies programs and versions

Which programs, which versions, Windows or Linux, workstation or cluster, and which licenses are available. OrcaFlex requires Windows; SIMA, Aqwa and OpenFOAM run on Linux.
Data
Pins down units and references

Coordinate system, origin, units and nondimensionalization of each program. WAMIT coefficients, for example, come out nondimensional and can only be compared after conversion.
Security
Sorts out access first

Naval defense projects and some offshore projects involve controlled information. Nothing leaves the client's network without approval from the compliance team, and Octo does not install or bypass licenses.
Architecture
Chooses the path

Java macros in STAR-CCM+; OrcFxAPI or Distributed OrcaFlex; sre --run or simapy in SIMA; /STD or aqwa.sh in Aqwa; text dictionaries in OpenFOAM.
Development
Writes the batch script

Prepares Python or shell scripts that generate the cases, run them one at a time or in a queue, keep a log of each execution and do not stop the batch when a case fails.
Review
Checks against a known case

Before the batch, it runs the base case and compares it with the result the engineer already has: same resistance, same RAO, same static tension. It checks by content, not by the end of the run.
Release
Runs in the authorized environment

Only with your OK and the approval of whoever manages the cluster, it runs on the machine cleared by the client and leaves results and log right there for review.
Documentation
Records what holds in your case

Commands, versions, parameters and what was confirmed on your installation. The next campaign starts from this record, and the script for one project is not taken as ready for another.

Octo does not validate models or sign analyses. Approval and certification belong to the engineer in charge, the classification society and the maritime authority. Sending controlled data (ITAR/EAR, U.S. export control regulations) to any external service, including AI, must first be assessed by the client's compliance team.

Every task, its own path.

The criteria Octo uses to choose, program by program, always starting from an approved base case.

Task	Path	Notes
Resistance curve at several speeds	STAR-CCM+ with a Java macro; OpenFOAM with one case per speed	Same mesh and same convergence criterion at every speed
Hydrodynamic coefficients and RAO	WAMIT (`.1` and `.4` files); Aqwa through a command file; OrcaWave	Check the nondimensionalization before passing to another program
Batch of mooring or riser cases	OrcaFlex via `OrcFxAPI` or Distributed OrcaFlex; SIMA via `sre --run` with `input=`	Wave, current, wind and seed matrix generated and logged
Irregular sea seeds	SIMA, one workspace per seed; OrcaFlex, one `.yml` per seed	Statistics over all seeds, not over one
Migrate a model from OrcaFlex to SIMA	SIMA 5.2.0 `.yml` importer	Under development, according to SINTEF; check weight, stiffness and static tension
Consolidate results	Reading `.sim` through the API, `results.h5`, WAMIT numeric files and CSV reports	Single table with the software and model version

From a one-off case to a campaign.

Three steps. Each one only makes sense after the previous one has shown results in your operation and passed the engineer in charge.

A proposal, not a promise

1 Today

Batches on demand

With the approved base case and a licensed machine, you ask in engineering language and Octo proposes the script and the case matrix.

“Resistance from 12 to 18 knots” becomes a batch script + table
A check on the base case before running the rest
Version and parameters noted in each result

Gain: the batch comes from a script, not from repeated clicks

2 Next

Checks between programs

The data handoff between potential theory, CFD and mooring analysis can get a routine check.

Mass, center of gravity and units matching on both sides
WAMIT coefficients converted and compared with the mooring model
List of discrepancies for the engineer to decide

Gain: the team reviews the list and decides

3 Later

Documented campaign

A whole campaign (cases, versions, results and comparison with model tests provided by the client) can get a reproducible record, prepared for review.

Processing record with commands and versions
Comparison with towing tank data, without judging the model
Supporting report for the engineer to sign their own

Gain: the campaign can be repeated and audited

Confirmed by a source.

Every point below has a source published by the vendor, by the project or by the responsible agency. The sources are in the next section.

points with a published source, each with its reference shown alongside.

ConfirmedSIMA runs without a screen, on Linux too: The sre executable accepts --commands file= and --run file=<model.stask> task=WorkflowTask workflow=<name> input="Hs=5.0;Tp=12.0;seed=1"; on Linux it is called sre, on Windows sre.exe.Source: SINTEF, “Running Without Graphical User Interface” (docs 5.0)
ConfirmedOrcaFlex works as a library: The OrcFxAPI Python interface has LoadData, CalculateStatics, RunSimulation and SaveSimulation; Orcina recommends 64-bit Windows. Version 11.6d, dated Nov 13, 2025 on the releases page.Source: OrcFxAPI Python reference; Orcina releases and requirements pages
ConfirmedWAMIT and Aqwa through files and the command line: WAMIT 7.6 has been available since Mar 4, 2026, in Windows and Linux versions, with numeric text outputs (.1: PER, I, J, Aij, Bij). In Aqwa 2026 R1, /STD reads a command file and, on Linux, the aqwa.sh script is used.Source: WAMIT news and 7.5 manual; Ansys Help 2026 R1
ConfirmedOpenFOAM includes a self-propulsion case: OpenFOAM 14 (Jul 14, 2026) includes the DTCHullProp example, of a hull's self-propulsion, and automatic tuning of the propeller disk; v2606 (Jun/2026) improves overset meshes. Both under GPL.Source: openfoam.org, release 14; openfoam.com, v2606

What Octo does, and what stays with you.

Octo prepares everything, but it does not sign. The document of record stays with whoever is accountable for it.

Octo prepares

Surveys, calculates, organizes and produces the documents: spreadsheets, reports, lists and drafts.

Deliverable: material ready to check

Your team checks

The licensed professional checks what Octo delivered before signing. If something doesn't add up, it goes back to Octo with the correction.

Step: checked by the person who signs

Who signs

Octo does not sign. Designs, technical reports, ART/RRT, statements of account and any official document are still signed by the licensed professional at the company or agency: here, the naval engineer in charge and the classification society.

Signature: naval engineer and classification society

Sources.

Documentation and announcements from the vendors themselves, used in the research.

Simcenter STAR-CCM+ 2606Siemens blog, Jul 1, 2026
Cadence completes the NUMECA acquisitionCadence press release, Feb 24, 2021
SHIPFLOW: requirementsWindows and Linux
OpenFOAM 14openfoam.org, Jul 14, 2026
OpenFOAM v2606openfoam.com, Jun/2026
WAMIT: newsVersion 7.6, Mar 4, 2026
WAMIT 7.5: output filesManual, section 5.2
Ansys Aqwa: command lineAnsys Help 2026 R1
Synopsys completes the Ansys acquisitionSynopsys press release, Jul 17, 2025 (HPCwire)
OrcaFlex: releasesOrcina, 11.6d
OrcFxAPI: Model classOrcina Python reference
Distributed OrcaFlexNetworked case queue
SIMA 5.2.0: release notesSINTEF
SIMA without a graphical interfaceSINTEF, docs 5.0
simapySINTEF Python library, MIT license

Your cases in batch, the analysis with your engineer.

The assessment starts with a base case your engineer has already approved and a licensed machine, without changing anything. You get a proposal of what can be run in batch, checked and consolidated, and you decide with that in hand.

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