Orcawave Analysis

OrcaWave Analysis Skill

Specialized expertise for OrcaWave diffraction/radiation analysis with panel method computations and OrcaFlex integration.

Version Metadata

version: 1.0.0
python_min_version: '3.10'
dependencies:
  hydrodynamics: '>=1.0.0,<2.0.0'
orcaflex_version: '>=11.0'
compatibility:
  tested_python:
  - '3.10'
  - '3.11'
  - '3.12'
  - '3.13'
  os:
  - Windows
  - Linux
  - macOS

Changelog

[1.0.0] - 2026-01-07

Added:

• Initial version metadata and dependency management
• Semantic versioning support
• Compatibility information for Python 3.10-3.13

Changed:

• Enhanced skill documentation structure

When to Use

• Diffraction analysis for wave-structure interaction
• Radiation analysis for added mass and damping
• Multi-body hydrodynamic interactions
• QTF (Quadratic Transfer Function) second-order calculations
• Panel mesh generation and optimization
• Batch processing of multiple configurations
• OrcaFlex hydrodynamic database generation
• Frequency domain marine analysis

Agent Capabilities

This skill integrates agent capabilities from /agents/orcawave/:

Core Capabilities

• Diffraction Analysis: Wave-structure interaction modeling
• Radiation Damping: Energy dissipation calculations
• Added Mass Calculation: Frequency-dependent inertia
• Multi-body Interaction: Coupled body dynamics
• QTF Computation: Second-order wave force calculations
• Mesh Generation: Panel mesh optimization and convergence
• Batch Processing: Parallel execution of multiple analyses
• OrcaFlex Integration: Hydrodynamic database generation

Required Tools

• OrcaWave
• Python 3.8+
• COM Interface
• NumPy
• Pandas

Expertise Areas

• Marine hydrodynamics
• Panel method theory
• Wave-structure interaction
• Frequency domain analysis
• Offshore engineering

Performance Targets

Prerequisites

• OrcaWave license (COM API access)
• Python environment with digitalmodel package
• Panel mesh geometry files

Python API

Basic Analysis

from digitalmodel.modules.orcawave.orcawave_analysis import OrcaWaveAnalysis

# Initialize analysis
orcawave = OrcaWaveAnalysis()

# Configure analysis
config = {
    "vessel_mesh": "geometry/hull_panels.dat",
    "water_depth": 1000.0,
    "frequencies": [0.05, 0.1, 0.15, 0.2, 0.3, 0.5],
    "wave_directions": [0, 45, 90, 135, 180]
}

# Run diffraction/radiation analysis
results = orcawave.run(config)

# Extract added mass at specific frequency
added_mass = results.get_added_mass(frequency=0.1)

# Extract damping
damping = results.get_damping(frequency=0.1)

# Get RAOs
raos = results.get_raos()

Batch Processing

from digitalmodel.modules.orcawave.batch import OrcaWaveBatch

# Initialize batch processor
batch = OrcaWaveBatch(parallel=True, max_workers=4)

# Define configurations
configs = [
    {"name": "draft_full", "draft": 20.0},
    {"name": "draft_ballast", "draft": 12.0},
    {"name": "draft_transit", "draft": 8.0}
]

# Run batch analysis
results = batch.run_batch(
    base_config="configs/base_analysis.yml",
    variations=configs,
    output_directory="results/draft_study/"
)

# Generate summary report
batch.generate_report(results, "results/batch_summary.html")

OrcaFlex Integration

from digitalmodel.modules.orcawave.orcaflex_export import OrcaFlexExporter

# Initialize exporter
exporter = OrcaFlexExporter()

# Load OrcaWave results
exporter.load_results("orcawave_results/vessel.dat")

# Export to OrcaFlex hydrodynamic database
exporter.create_hydrodynamic_database(
    output_file="orcaflex_models/vessel_hydro.yml",
    include_qtf=True,
    viscous_damping={
        "roll": 0.05,  # 5% critical
        "pitch": 0.03,
        "heave": 0.02
    }
)

Mesh Convergence Study

from digitalmodel.modules.orcawave.mesh_study import MeshConvergenceStudy

# Initialize study
study = MeshConvergenceStudy()

# Define mesh sizes to test
mesh_sizes = [2.0, 1.5, 1.0, 0.75, 0.5]

# Run convergence study
convergence = study.run(
    geometry="geometry/hull.step",
    mesh_sizes=mesh_sizes,
    target_frequency=0.1,
    output_directory="results/mesh_study/"
)

# Plot convergence
study.plot_convergence(
    convergence,
    output_file="results/mesh_convergence.html"
)

# Get recommended mesh size
recommended = study.get_recommended_size(convergence, tolerance=0.02)
print(f"Recommended mesh size: {recommended}m")

Configuration Examples

Standard Analysis

# configs/orcawave_analysis.yml

orcawave:
  vessel:
    name: "FPSO"
    mesh_file: "geometry/hull_panels.dat"
    mass: 250000.0  # tonnes
    cog: [150.0, 0.0, 15.0]  # m
    radii_of_gyration: [25.0, 80.0, 82.0]  # m

  environment:
    water_depth: 1000.0  # m
    water_density: 1025.0  # kg/m3

  analysis:
    frequencies:
      min: 0.02
      max: 2.0
      count: 50
    wave_directions: [0, 30, 60, 90, 120, 150, 180]

  options:
    compute_qtf: true
    compute_drift: true
    irregular_frequencies: "lid_method"

  output:
    format: ["csv", "orcaflex"]
    directory: "results/"

Multi-Body Analysis

orcawave:
  multi_body:
    enabled: true
    bodies:
      - name: "FPSO"
        mesh_file: "geometry/fpso_panels.dat"
        position: [0, 0, 0]
      - name: "Offloading_Tanker"
        mesh_file: "geometry/tanker_panels.dat"
        position: [300, 50, 0]  # Side-by-side

  coupling:
    hydrodynamic: true
    mechanical: false  # Handle in OrcaFlex

  output:
    individual_results: true
    coupled_results: true

Integration Targets

Workflow Support

• Parallel Processing: Multi-core execution for batch analyses
• Batch Execution: Run multiple configurations automatically
• Error Recovery: Automatic retry with license management
• License Management: Check and queue for available licenses

MCP Tool Integration

Swarm Coordination

// Initialize panel method analysis swarm
mcp__claude-flow__swarm_init { topology: "star", maxAgents: 3 }

// Spawn specialized agents
mcp__claude-flow__agent_spawn { type: "analyst", name: "orcawave-processor" }
mcp__claude-flow__agent_spawn { type: "code-analyzer", name: "mesh-validator" }

Memory Coordination

// Store analysis configuration
mcp__claude-flow__memory_usage {
  action: "store",
  key: "orcawave/analysis/config",
  namespace: "hydrodynamics",
  value: JSON.stringify({
    vessel: "FPSO",
    mesh_panels: 5000,
    frequencies: 50,
    timestamp: Date.now()
  })
}

// Track batch progress
mcp__claude-flow__memory_usage {
  action: "store",
  key: "orcawave/batch/progress",
  namespace: "hydrodynamics",
  value: JSON.stringify({
    total: 100,
    completed: 45,
    failed: 2,
    running: 4
  })
}

Benchmark Validation vs AQWA

Compare OrcaWave results with AQWA for validation at peak/significant values.

from digitalmodel.modules.diffraction.comparison_framework import PeakRAOComparator
from digitalmodel.modules.diffraction.aqwa_converter import AQWAConverter
from digitalmodel.modules.diffraction.orcawave_converter import OrcaWaveConverter

# Extract both datasets
aqwa_results = AQWAConverter(...).convert_to_unified_schema(...)
orcawave_results = OrcaWaveConverter(vessel).convert()

# Peak-focused comparison
comparator = PeakRAOComparator(
    aqwa_results=aqwa_results,
    orcawave_results=orcawave_results,
    peak_threshold=0.10,  # ≥10% of peak
    tolerance=0.05  # 5% tolerance
)

# Run comparison
results = comparator.compare_peaks()

# Generate report
comparator.generate_peak_report_html(
    results,
    output_file="benchmark/comparison_report.html"
)

Validation Criteria:

• 5% tolerance on peak values
• 90% of significant points within 5%
• Significant = RAO ≥ 10% of peak magnitude
• Focus on resonance regions

Benchmark Location: docs/modules/orcawave/L01_aqwa_benchmark/

Automated Scripts:

• run_comparison.py - Full comparison with all data points
• run_comparison_peaks.py - Peak-focused validation (recommended)

Best Practices

1. Mesh Quality: Ensure panel mesh convergence before production runs
2. Frequency Range: Cover wave spectrum frequencies of interest
3. Direction Resolution: Use finer resolution for asymmetric vessels
4. QTF Computation: Include second-order effects for deep-draft vessels
5. Validation: Cross-check peak values with AQWA (5% tolerance on significant values)
6. License Management: Queue analyses during peak license usage
7. Benchmark Testing: Run AQWA comparison before production use

Error Handling

License Issues

# Check license before batch
from digitalmodel.modules.orcawave.license import check_orcawave_license

if not check_orcawave_license():
    print("Waiting for license...")
    wait_for_license(timeout=3600)  # Wait up to 1 hour

Mesh Issues

# Validate mesh before analysis
from digitalmodel.modules.orcawave.mesh import validate_panel_mesh

validation = validate_panel_mesh("geometry/hull_panels.dat")
if validation["issues"]:
    for issue in validation["issues"]:
        print(f"Mesh issue: {issue}")

Related Skills

• diffraction-analysis - Master skill for all diffraction workflows
• bemrosetta - AQWA → OrcaFlex conversion with QTF and mesh support
• orcaflex-modeling - Apply hydrodynamic database in OrcaFlex
• aqwa-analysis - AQWA validation and comparison
• gmsh-meshing - Panel mesh generation
• hydrodynamics - Coefficient management

References

• Orcina OrcaWave Documentation
• Newman, J.N.: Marine Hydrodynamics
• Faltinsen, O.M.: Sea Loads on Ships and Offshore Structures
• Agent Configuration: agents/orcawave/agent_config.json

Version History

• 1.1.0 (2026-01-05): Added AQWA benchmark comparison, peak-focused validation framework, 5% tolerance criteria for significant values
• 1.0.0 (2025-01-02): Initial release from agents/orcawave/ configuration

OrcaWave API Properties Reference

These properties return the same data as shown on the validation page in the OrcaWave GUI:

Frequency/Period Data:

• headings - Wave heading angles (degrees)
• frequencies - Wave frequencies (rad/s)
• angularFrequencies - Angular frequencies
• periods - Wave periods (seconds)
• periodsOrFrequencies - Display format

Hydrostatic and Frequency-Dependent:

• hydrostaticResults - Hydrostatic stiffness matrix
• addedMass - Frequency-dependent added mass
• infiniteFrequencyAddedMass - Infinite frequency added mass
• damping - Radiation damping coefficients

RAO Data:

• loadRAOsHaskind - Force/moment RAOs (Haskind method) - N/m, N·m/m
• loadRAOsDiffraction - Force/moment RAOs (diffraction) - N/m, N·m/m
• displacementRAOs - Motion/displacement RAOs (m/m, rad/m) - Use for AQWA comparison

QTF Data:

• meanDriftHeadingPairs - Mean drift force heading combinations
• QTFHeadingPairs - QTF heading pairs
• QTFFrequencies, QTFAngularFrequencies, QTFPeriods, QTFPeriodsOrFrequencies

Mean Drift and Pressure:

• meanDriftLoadPressureIntegration - Mean drift from pressure
• meanDriftLoadControlSurface - Mean drift from control surface
• meanDriftLoadMomentumConservation - Mean drift from momentum

Field Points:

• fieldPointPressure - Pressure at field points
• fieldPointRAO - RAO at field points
• fieldPointVelocity - Velocity at field points
• fieldPointRAOGradient - RAO gradients

Panel Data:

• panelGeometry - Panel mesh geometry
• panelPressure - Panel pressure (total)
• panelPressureDiffraction - Panel pressure (diffraction component)
• panelPressureRadiation - Panel pressure (radiation component)
• panelVelocity - Panel velocities
• panelVelocityDiffraction - Panel velocity (diffraction)
• panelVelocityRadiation - Panel velocity (radiation)
• panelPotentialInfiniteFrequencyRadiation - Infinite frequency potential

Quadratic Loads:

• quadraticLoadFromPressureIntegration - Quadratic loads from pressure
• quadraticLoadFromControlSurface - Quadratic loads from control surface
• directPotentialLoad - Direct potential loads
• indirectPotentialLoad - Indirect potential loads

Roll Damping:

• extraRollDamping - Additional roll damping
• rollDampingPercentCritical - Roll damping as % of critical