Seastead Design Optimizer
Interactive Trade-off Analysis: Leg Profile, Drag, Wave Response, and Stabilization
| Leg Profile |
Dimensions
(L, Draft, Chord, Width) |
Waterplane Area
(Total Sq Ft) |
Restoring Force
(Lbs per ft height) |
Est. Speed
(Knots) |
Heave w/o Stabilizer
(ft) |
Stabilizer Force
(Total Lbs) |
Stab Influence
(Ft Equivalent) |
Final Heave Motion
(ft) |
Est. Weight per Leg
(Marine Alum, lbs) |
Est. Cost (1 Leg + 1 Stab)
(Marine Alum) |
Calculation Notes & Assumptions
- Volume Matching: NACA 0040 and 0025 dimensions are calculated to exactly match the displaced volume of the NACA 0030 baseline (39 ft length, 19.5 ft draft, 10 ft chord, 3 ft max width), ensuring the seastead's buoyancy and weight capacity remain constant across profiles.
- NACA Cross-Section Area: Approximated as Area = 0.6 * t/c * Chord * Width, where t/c is the thickness ratio (0.30, 0.40, 0.25).
- Drag & Speed: Drag is calculated at the foil's Center of Buoyancy draft. Form drag uses a streamlined body coefficient (0.1), and skin friction uses a flat plate approximation. Speed is derived by balancing effective thrust (Power * Efficiency / Speed) against total drag for 3 legs.
- Wave Response (Heave): Evaluates the top half of the wave (WaveHeight/2) over 1/4 of the wave period. Unstabilized heave assumes the waterplane reacts to the wave slope and velocity, modified by an added mass coefficient (Ca=1.0) and drag damping.
- Stabilizer Influence: Calculated as Stabilizer Force / Restoring Force per ft. This translates the dynamic lift generated by the moving stabilizers into an equivalent reduction in wave height.
- Weights & Costs: Structural weight is estimated at 15% of displaced water weight per leg. Cost assumes $12/lb for marine-grade aluminum fabrication, plus $2,500 for the actuator and small parts per stabilizer.
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