vamseeachanta Viv Analysis
When to Use
- VIV analysis for risers and pipelines
- Natural frequency calculation for tubular members
- Vortex shedding frequency analysis
- VIV fatigue damage assessment
- Tubular member VIV screening
- Safety factor evaluation against VIV criteria
Prerequisites
- Python environment with
digitalmodelpackage installed - Member geometry and material properties
- Current velocity profiles
- For risers: tension distribution along length
Python API
Natural Frequency Calculation
from digitalmodel.subsea.viv_analysis.viv_analysis import VIVAnalysis
from digitalmodel.subsea.viv_analysis.viv_tubular_members import VIVTubularMembers
# Initialize analysis
viv = VIVAnalysis()
# Define member properties
member = {
"length": 50.0,
*See sub-skills for full details.*
### Vortex Shedding Analysis
```python
# Vortex shedding frequency
diameter = 0.5 # meters
current_velocity = 1.5 # m/s
strouhal = 0.2
shedding_freq = viv.vortex_shedding_frequency(
diameter=diameter,
velocity=current_velocity,
strouhal_number=strouhal
*See sub-skills for full details.*
### Tubular Member Analysis
```python
from digitalmodel.subsea.viv_analysis.viv_tubular_members import VIVTubularMembers
# Initialize tubular member analysis
tubular = VIVTubularMembers()
# Define member
member_props = {
"name": "Brace1",
"outer_diameter": 0.324,
*See sub-skills for full details.*
### VIV Fatigue Assessment
```python
from digitalmodel.subsea.viv_analysis.viv_fatigue import VIVFatigue
# Initialize VIV fatigue analysis
viv_fatigue = VIVFatigue()
# Calculate VIV-induced stress range
stress_range = viv_fatigue.calculate_stress_range(
amplitude=0.5, # VIV amplitude in diameters
diameter=0.324,
*See sub-skills for full details.*
## Key Classes
| Class | Purpose |
|-------|---------|
| `VIVAnalysis` | Main VIV analysis router |
| `VIVTubularMembers` | Tubular member assessment |
| `VIVAnalysisComponents` | Component-level analysis |
| `VIVFatigue` | VIV-induced fatigue damage |
## Related Skills
- [catenary-riser](../catenary-riser/SKILL.md) - Riser configuration
- [fatigue-analysis](../fatigue-analysis/SKILL.md) - VIV fatigue damage
- [structural-analysis](../structural-analysis/SKILL.md) - Stress verification
## References
- DNV-RP-C205: Environmental Conditions and Environmental Loads
- DNV-RP-F105: Free Spanning Pipelines
- Blevins, R.D.: Flow-Induced Vibration
## Sub-Skills
- [Best Practices](best-practices/SKILL.md)
## Sub-Skills
- [Version Metadata](version-metadata/SKILL.md)
- [[1.0.0] - 2026-01-07](100-2026-01-07/SKILL.md)
- [1. Natural Frequency Analysis (+3)](1-natural-frequency-analysis/SKILL.md)
- [Strouhal Number (+2)](strouhal-number/SKILL.md)
- [Complete VIV Screening Workflow](complete-viv-screening-workflow/SKILL.md)
- [Natural Frequencies JSON (+1)](natural-frequencies-json/SKILL.md)
- [Design Code References](design-code-references/SKILL.md)