Orcawave Damping Sweep

Orcawave Damping Sweep

When to Use

• Parametric studies of viscous damping effects
• Roll damping coefficient optimization
• Comparing radiation damping with viscous damping
• Tuning damping to match model test data
• Estimating bilge keel damping contribution
• Critical damping ratio calculations
• Sensitivity analysis for motion predictions
• Roll resonance mitigation studies

Python API

Basic Damping Sweep

from digitalmodel.orcawave.damping import DampingSweep

# Initialize sweep
sweep = DampingSweep()

# Load base model
sweep.load_model("models/fpso.owr")

# Define damping values to sweep

*See sub-skills for full details.*
### Multi-Parameter Sweep

```python
from digitalmodel.orcawave.damping import MultiParameterDampingSweep

# Initialize multi-parameter sweep
sweep = MultiParameterDampingSweep()

# Load model
sweep.load_model("models/fpso.owr")

# Define parameter space

*See sub-skills for full details.*
### Critical Damping Calculation

```python
from digitalmodel.orcawave.damping import CriticalDampingCalculator

# Initialize calculator
calc = CriticalDampingCalculator()

# Load model with mass and stiffness
calc.load_model("models/fpso.owr")

# Calculate critical damping for each DOF

*See sub-skills for full details.*
### Model Test Comparison

```python
from digitalmodel.orcawave.damping import ModelTestComparison

# Initialize comparison
comparison = ModelTestComparison()

# Load OrcaWave results
comparison.load_orcawave_results("results/fpso.owr")

# Load model test data

*See sub-skills for full details.*
### Bilge Keel Estimation

```python
from digitalmodel.orcawave.damping import BilgeKeelDamping

# Initialize bilge keel damping estimator
bk = BilgeKeelDamping()

# Configure vessel parameters
bk.configure_vessel(
    beam=50.0,          # m
    draft=22.0,         # m

*See sub-skills for full details.*
### Damping-Period Relationship

```python
from digitalmodel.orcawave.damping import DampingPeriodAnalyzer

# Analyze damping vs period relationship
analyzer = DampingPeriodAnalyzer()

# Load OrcaWave radiation damping results
analyzer.load_results("models/fpso.owr")

# Extract frequency-dependent radiation damping

*See sub-skills for full details.*

## Related Skills

- [orcawave-analysis](../orcawave-analysis/SKILL.md) - OrcaWave diffraction analysis
- [orcawave-to-orcaflex](../orcawave-to-orcaflex/SKILL.md) - Export with damping
- [hydrodynamics](../hydrodynamics/SKILL.md) - Coefficient management
- [viv-analysis](../viv-analysis/SKILL.md) - Vibration damping

## References

- Himeno, Y.: Prediction of Ship Roll Damping - State of the Art
- Ikeda, Y.: Prediction Methods of Roll Damping of Ships
- OrcaWave Roll Damping Documentation
- Script: `scripts/python/digitalmodel/modules/run_orcawave_damping_sweep.py`

---

**Version History**

- **1.0.0** (2026-01-17): Initial release with damping sweep, model test comparison, and bilge keel estimation

## Sub-Skills

- [Best Practices](best-practices/SKILL.md)

## Sub-Skills

- [Error Handling](error-handling/SKILL.md)

## Sub-Skills

- [Version Metadata](version-metadata/SKILL.md)
- [Total Damping Composition (+1)](total-damping-composition/SKILL.md)
- [Damping Sweep Configuration (+1)](damping-sweep-configuration/SKILL.md)
- [CLI Usage](cli-usage/SKILL.md)
- [Typical Values by Vessel Type (+1)](typical-values-by-vessel-type/SKILL.md)
- [Damping-Related Properties](damping-related-properties/SKILL.md)


## Documentation Reference

OrcaWave topics (`data/llm-wiki/orcawave/`):
- `Theory,Dampinglid.md` -- damping lid method for free-surface suppression
- `Theory,Hydrodynamicdrag.md` -- linearized viscous drag in frequency domain
- `Results,Rolldamping.md` -- roll damping results output
- `Results,Addedmassanddamping.md` -- radiation damping vs frequency
- `Data,Springdampers.md` -- external damping specification

OrcaFlex topics (`data/llm-wiki/orcaflex/`):
- `Vesseltypes,Otherdamping.md` -- additional damping in vessel types
- `Vesseltheory,Otherdamping.md` -- damping theory beyond radiation

Papers (`data/llm-wiki/papers/`):
- `Structural-Damping.md` -- structural damping concepts
- `Spar-Buoy-Equation-of-Motion.md` -- damping in spar buoy dynamics