vamseeachanta AQWA Reference Skill
Solver internals, OPTIONS keywords, external damping/stiffness cards, and MCP integration for ANSYS AQWA. See aqwa for Python API.
RESTART Stage Reference
| RESTART | Stages Run | Purpose | Typical Use |
|---|---|---|---|
1 2 |
Geometry + radiation | Added mass & damping matrices only | Quick coefficient extraction |
1 5 |
Full diffraction | First-order RAOs + added mass + damping | Standard frequency-domain analysis |
1 8 |
Full + QTF | Everything in 1-5 plus second-order QTF forces | Mooring design, slow drift |
OPTIONS Keyword Reference
| Keyword | Purpose | When to Use |
|---|---|---|
GOON |
Continue past non-fatal mesh errors | Always (recommended) |
LHFR |
Remove irregular frequency effects (lid method) | When remove_irregular_frequencies: true |
MQTF |
Enable QTF computation | When qtf_calculation: true and RESTART includes stages 6-8 |
AHD1 |
Generate .AH1 ASCII hydrodynamic database | When output_ah1: true |
REST END |
End OPTIONS block (RESTART must follow immediately) | Always (required) |
Card Ordering in .dat File
OPTIONS GOON <- Always first (error tolerance)
OPTIONS LHFR MQTF REST END <- Feature options + terminator
OPTIONS AHD1 <- Optional output format (BEFORE REST END line)
RESTART 1 5 <- Must immediately follow REST END
FIDP External Damping Cards (Deck 7)
FIDP (Frequency Independent DamPing) cards in Deck 7 WFS1:
- Format:
{6sp}FIDP{5sp}{row_idx 5-wide}{6 x 10-char scientific notation values} - Generated when
vessel.external_dampinghas non-zero entries in spec.yml - Critical: FIDP has ZERO effect on frequency-domain RAOs (stages 1-5)
- FIDP only affects time-domain response analysis (stages 6+, AQWA-DRIFT/NAUT)
- OrcaWave DOES include external damping in frequency-domain RAOs — this creates an asymmetry
FISK External Stiffness Cards (Deck 7)
FISK (Frequency Independent Stiffness) cards — same format as FIDP but for vessel.external_stiffness.
Backend Bug: RESTART Always 1-5
aqwa_backend.py:412 hardcodes RESTART 1 5 regardless of qtf_calculation. When qtf_calculation: true, should use RESTART 1 8 to actually compute QTF. The OPTIONS MQTF flag is correctly generated but QTF stages never execute with RESTART 1 5.
MCP Tool Integration
Swarm Coordination
mcp__claude-flow__swarm_init { topology: "mesh", maxAgents: 4 }
mcp__claude-flow__agent_spawn { type: "analyst", name: "aqwa-processor" }
mcp__claude-flow__agent_spawn { type: "code-analyzer", name: "coefficient-extractor" }
Memory Coordination
mcp__claude-flow__memory_usage {
action: "store",
key: "aqwa/raos/vessel",
namespace: "hydrodynamics",
value: JSON.stringify({ vessel: "FPSO", directions: [0, 45, 90, 135, 180], frequencies: 50 })
}
Phased Processing Workflow
- Discovery: Identify AQWA output files
- Quality: Validate file integrity
- Extraction: Extract RAOs and coefficients
- Synthesis: Combine multi-body results
- Validation: Check physical consistency
- Integration: Export to OrcaFlex format
Related Skills
- aqwa — Hub skill with Python API
- aqwa/input — Input formats and configurations
- aqwa/output — Output formats and validation