aceengineer/digitalmodel-diffraction-rao

digitalmodel Diffraction RAOs (multi-vessel, de-identified)

Analysis/computation results published for query + visualization via the Hugging Face datasets-server API. One row per (vessel, solver, damping, dof, frequency, heading). Vessels are referenced only by de-identified vessel_db IDs.

Tables

config	rows	cols
hydrostatics	5	7
rao	8448	11

Schema 1.1.0 — solver column

The rao table now carries a solver column (AQWA | OrcaWave), added when the first vessel gained results from two solvers. Filter on vessel_id and solver (and damping_zeta_pct); rows published under schema 1.0.0 were backfilled from the vessel table below at the 1.1.0 migration and are otherwise byte-identical.

Series in rao

vessel_id	solver	damping_zeta_pct	rows	basis
install_bokalift_2	OrcaWave	5, 10	600	parametric hull from public particulars
drill_samsung96k_1	AQWA	0	2700	hull-class-level de-identified model, survival loading condition
drill_samsung96k_1	OrcaWave	0	2574	same hull class/condition; radiation-only (no external damping), open moonpool (no lid)
drill_samsung96k_1	OrcaWave	5	2574	as ζ=0 plus external linear roll damping B44 (total roll ζ ≈ 5 %)

Data-quality notes

Screening-grade — faithful-to-solver ≠ correct for design. No model here is class-approved.

install_bokalift_2 (OrcaWave, parametric screening)

• Low-frequency artifact (flagged, not omitted): in rao, heave & sway at freq ≤ 0.35 rad/s (T ≥ 18 s) in non-beam headings are physically implausible (heave ≈ 7–9 m/m where beam seas correctly show ≈ 1.1). 40 rows carry reliability = "low_freq_artifact". Use freq ≥ 0.5 rad/s. Tracked: digitalmodel#1548.
• Withheld table — added_mass_damping: the source matrices declare units kg / kg·m² but magnitudes are consistent with te / te·m² (~1000× off, e.g. heave added-mass 58,447 vs ~1e8 kg expected). Withheld pending unit reconciliation. Tracked: digitalmodel#1550.
• Withheld — operation-envelope (Hs/Tp) limits: derived limits reach implausible values (~17 m Hs heavy-lift) and would mislead as operational limits. A class panel mesh is required first.
• Roll at resonance is high (23.5 deg/m at ζ=5 %, 19.2 at ζ=10 %) — a real, expected consequence of light damping, not an artifact.

drill_samsung96k_1 · AQWA (ζ = 0)

• damping_zeta_pct = 0 means NO external/viscous roll damping — radiation damping only. The roll peak (15.6 deg/m at T = 19 s, beam seas) is therefore an undamped potential-flow upper bound, not an operability prediction; apply an external roll damping model before use.
• Resonance band flagged (50 rows reliability = "undamped_resonance"): roll rows at T = 18.48 and 18.98 s (all headings) are damping-controlled, matching the flag treatment of the OrcaWave ζ=0 series. Coupled sway/yaw are NOT flagged here — the AQWA grid straddles the resonance, so their contamination is negligible (sway ≤ 1.14 m/m, yaw ≤ 0.064 deg/m).
• Frequency band is roll-focused: 18 frequencies covering T ≈ 15.5–31.4 s (refined around the roll-response band). No rows outside this band — absence is by scope, not omission.
• Moonpool: the panel model includes moonpool walls with no damping lid; moonpool-resonance effects near the moonpool natural period are expected and not suppressed.
• Long-period sanity passed: beam-seas heave → 1.0 m/m and head-seas surge → 0.95 m/m at T = 31.4 s.
• Headings span −180°…180° at 15° (25 values).

drill_samsung96k_1 · OrcaWave (ζ = 0 and ζ = 5)

• Grid: 33 frequencies (T ≈ 4–31.4 s, refined 10–22 s at 0.5 s) × 13 headings (0°–180° at 15°; port/starboard symmetry assumed) × 6 DOFs = 2,574 rows per series. Phases in the Orcina lag convention — align conventions before phase-level comparison with AQWA.
• ζ = 0 series — resonance band flagged (117 rows reliability = "undamped_resonance"): radiation-only roll damping for this hull is ζ ≈ 0.2 % critical, so the roll RAO at resonance (358 deg/m at T = 18.5 s, beam seas) and the coupled sway/yaw peaks are damping-controlled numerical upper bounds, not physical response predictions. Roll, sway and yaw rows with T = 17.9–19.1 s carry the flag. Off-resonance rows are usable screening values. The open moonpool (no damping lid) is also unsuppressed in this run.
• ζ = 5 series: adds external linear roll damping B44 equivalent to ≈ 5 % total critical; beam-seas roll peak drops to 4.48 deg/m at T = 18.5 s (~80× below the ζ=0 value) — use this series as the damping-sensitivity anchor; match your own damping budget before design use.
• Cross-solver agreement (same hull, both ζ=0): off-resonance beam-seas roll RAOs agree with the AQWA series within ~12–18 % — consistent for undamped potential-flow codes on different grids. Resonance-peak magnitudes are NOT comparable between the two ζ=0 series: the AQWA grid straddles the peak while the OrcaWave grid samples it exactly (grid sampling, not physics). Roll natural period agrees at 18.5–19.0 s in both codes.
• Withheld — added mass & damping matrices: present in the source results but not yet published pending the same unit reconciliation as digitalmodel#1550.

Provenance

• Source repo: digitalmodel · solvers: orcawave-diffraction@1537 (install_bokalift_2), AQWA v261 licensed-run lane (drill_samsung96k_1 AQWA, run lr_acma_bb24945c4b8b), OrcaWave 11.x licensed-run lane (drill_samsung96k_1 OrcaWave: ζ=0 run lr_acma_2a4a51f24387, ζ=5 run lr_acma_36fb1ffbc5e0)

• Schema version: 1.1.0 (adds solver; 1.0.0 rows backfilled per the series table)

• Source snapshots (sha256):

• hydrostatics.parquet — sha256 cb0141548b6bf07f3892560f4a564147bb76648fcc7ea1c3383577ff62357f53 (adds 3 drill_samsung96k_1 rows: class-level analysis mass for the OrcaWave series; the AQWA row's mass_te is null — genuinely absent from its de-identified source. CoG/CoB/stiffness remain withheld: GM-recoverable.)

• rao.parquet — sha256 d855c015efb7bd13e05429da2e54613cab213421fde4f4eb57c967b53f5a5347 (2026-07-16b: AQWA resonance-band flags added; values byte-identical to the prior revision)

• drill_samsung96k_1 AQWA de-identified source JSON — sha256 ef6e7d90b52b4bf730c94e7aebcc1b295008ccb9b9c80ad3e0ef1a5d26c05dec

• drill_samsung96k_1 OrcaWave ζ=0 de-identified source JSON — sha256 af4b37cb0acde7d7f68b7c2f60ac2cc34b8928caeb5e7aa3e06ade13ad81a081

• drill_samsung96k_1 OrcaWave ζ=5 de-identified source JSON — sha256 36acd2d4943a97a44d2b31fa7bebda7623ef56b6bc0d9bb304af6b3f05bf5fa5

Vessels are de-identified: install_bokalift_2 from public particulars; drill_samsung96k_1 identified only at hull-class level. Not a run-identity ledger (that is the separate aceengineer/*-runs contract).

Nulls are genuine missing values (non-finite floats were coerced to null). Load a table: pandas.read_parquet(hf_hub_download("aceengineer/digitalmodel-diffraction-rao", "<config>.parquet", repo_type="dataset")).

Live visualizations of this dataset: https://www.aceengineer.com/reports/diffraction/