vamseeachanta Orcawave Qtf Analysis
When to Use
- Computing mean drift forces for mooring analysis
- Generating full QTF matrices for slow-drift response
- Difference-frequency force calculation
- Sum-frequency force calculation (springing)
- Newman approximation vs full QTF comparison
- Deep water vs shallow water second-order effects
- Moored vessel slow-drift motion prediction
Python API
Basic QTF Computation
from digitalmodel.orcawave.qtf import OrcaWaveQTF
# Initialize QTF analysis
qtf = OrcaWaveQTF()
# Load OrcaWave model with first-order results
qtf.load_model("models/fpso.owr")
# Configure QTF computation
*See sub-skills for full details.*
### Full QTF Matrix Generation
```python
from digitalmodel.orcawave.qtf import FullQTFComputation
# Initialize full QTF computation
full_qtf = FullQTFComputation()
# Configure frequency pairs
full_qtf.configure(
frequencies=np.linspace(0.02, 0.5, 25), # rad/s
heading_pairs=[
*See sub-skills for full details.*
### Newman Approximation
```python
from digitalmodel.orcawave.qtf import NewmanApproximation
# Initialize Newman approximation
newman = NewmanApproximation()
# Load first-order results
newman.load_first_order_results("results/fpso_raos.csv")
# Compute approximate QTF
*See sub-skills for full details.*
### Mean Drift Analysis
```python
from digitalmodel.orcawave.qtf import MeanDriftAnalyzer
# Initialize analyzer
drift = MeanDriftAnalyzer()
# Load OrcaWave results
drift.load_results("models/fpso.owr")
# Extract mean drift by method
*See sub-skills for full details.*
### Slow Drift Response
```python
from digitalmodel.orcawave.qtf import SlowDriftResponse
# Initialize slow drift analysis
slow_drift = SlowDriftResponse()
# Load QTF data
slow_drift.load_qtf("results/fpso_qtf.yml")
# Configure sea state
*See sub-skills for full details.*
## Related Skills
- [orcawave-analysis](../orcawave-analysis/SKILL.md) - First-order diffraction analysis
- [mooring-design](../mooring-design/SKILL.md) - Mooring system design
- [hydrodynamics](../hydrodynamics/SKILL.md) - Wave loading management
- [orcaflex/modeling](../orcaflex/modeling/SKILL.md) - Time-domain simulation
## References
- Pinkster, J.A.: Low Frequency Second Order Wave Exciting Forces
- Newman, J.N.: Second-Order Wave Forces on a Vertical Cylinder
- Standing, R.G.: Low Frequency Wave Drift Forces
- OrcaWave QTF Documentation
---
**Version History**
- **1.0.0** (2026-01-17): Initial release with full QTF, Newman approximation, and slow drift analysis
## Sub-Skills
- [When to Use Full QTF vs Newman (+2)](when-to-use-full-qtf-vs-newman/SKILL.md)
## Sub-Skills
- [Error Handling](error-handling/SKILL.md)
## Sub-Skills
- [Version Metadata](version-metadata/SKILL.md)
- [Force Components (+1)](force-components/SKILL.md)
- [QTF Analysis Configuration (+1)](qtf-analysis-configuration/SKILL.md)
- [Available Data (+1)](available-data/SKILL.md)
- [CLI Usage](cli-usage/SKILL.md)
## Documentation Reference
OrcaWave topics (`data/llm-wiki/orcawave/`):
- `Data,QTFs.md` -- QTF computation configuration
- `Theory,Second-orderequations.md` -- second-order BVP theory
- `Results,Quadraticloads.md` -- QTF output (mean drift, full QTF matrices)
- `Results,Potentialloads.md` -- potential-based load results
- `Data,Environment.md` -- water depth affecting second-order effects
OrcaFlex topics (`data/llm-wiki/orcaflex/`):
- `Vesseltypes,WavedriftandsumfrequencyQTFs.md` -- QTF data in vessel types
- `Vesseltheory,Wavedriftandsumfrequencyloads.md` -- drift/sum-frequency theory
- `Modellingvesselslowdrift.md` -- slow drift modelling in OrcaFlex