Surf / pump foil — 900 mm reference front wingvsMIT Daedalus 88 — the 34 m human-powered wing
root section a18 → dae11 · tip section — → dae31 · area 111865 mm² → 31712462 mm² · span 900 mm → 34100 mm · tip chord 76 mm → 762 mm · mac 128 mm → 939 mm
units
These analyses are not directly comparable
- different fluids (water-salt vs air) — density and viscosity both differ, so the drag numbers are not on the same footing
- different trim loads (932 N vs 1020 N) — each wing is carrying a different weight
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Surf / pump foil — 900 mm reference front wing
- MIT Daedalus 88 — the 34 m human-powered wing
What changed
| Property | Surf / pump foil | MIT Daedalus 88 | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 900 mm | 34100 mm | +33200 mm | +3688.9% |
| Root chord | 150 mm | 1050 mm | +900 mm | +600.0% |
| Tip chord | 76 mm | 762 mm | +686 mm | +902.6% |
| Sweep parameter | 8.553 | 0.484 | -8.069 | -94.3% |
| Dihedral | -1.50° | 1.00° | +2.50° | -166.7% |
| Tip twist | -2.00° | -1.50° | +0.50° | -25.0% |
| TE thickness | 0 mm | 2 mm | +1 mm | +500.0% |
| Sections | 30 | 40 | +10 | +33.3% |
| Tip cap peak (chord fraction) | 0.450 | 0.500 | +0.050 | +11.1% |
| Tip cap reach | 0.350 | 0.250 | -0.100 | -28.6% |
| Derived | ||||
| Aspect ratio | 7.241 | 36.667 | +29.426 | +406.4% |
| Area | 111865 mm² | 31712462 mm² | +31600597 mm² | +28249.0% |
| Taper | 0.507 | 0.726 | +0.219 | +43.2% |
| MAC | 128 mm | 939 mm | +811 mm | +631.6% |
| Sections | ||||
| Root section | a18 | dae11 | changed | — |
| Tip section | — | dae31 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 900 mm | |||
| Chord deviation (RMS) | 809 mm | |||
| Twist deviation (max) | 0.69° | |||
| Dihedral deviation (max) | 309 mm | |||
| Tip cap deviation (max) | 16687 mm | |||
Performance
CoefficientsDimensionless — how good the shape is, independent of size and speed.
ForcesNewtons and watts — what each wing actually carries and costs at this condition.
Spanwise
withheld — “Surf / pump foil” integrates to CL 0.022 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.363 (0.06×); “MIT Daedalus 88” integrates to CL 0.120 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.913 (0.13×). A loading that does not integrate back to its own wing’s CL is not a coarse curve, it is a wrong one.
mixed fluids (water (sea), air)
data
| V (kt) | Surf / pump foil | MIT Daedalus 88 |
|---|---|---|
| 11.54 | 25.48 | 37.99 |
| 12.15 | 25.81 | 41.06 |
| 12.61 | 25.84 | 43.38 |
| 13.00 | 25.87 | 44.69 |
| 13.68 | 25.63 | 46.93 |
| 13.85 | 25.57 | 47.31 |
| 14.70 | 24.96 | 49.17 |
| 14.74 | 24.92 | 49.26 |
| 15.55 | 24.15 | 49.22 |