Gossamer Condor — 96 ft of wing at 11 mphvsSurf / pump foil — 900 mm reference front wing
root section l7769 → a18 · dihedral 3.00° → -1.50° · area 66293551 mm² → 111865 mm² · span 29260 mm → 900 mm · root chord 2862 mm → 150 mm · tip chord 1431 mm → 76 mm
units
These analyses are not directly comparable
- different fluids (air vs water-salt) — density and viscosity both differ, so the drag numbers are not on the same footing
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Gossamer Condor — 96 ft of wing at 11 mph
- Surf / pump foil — 900 mm reference front wing
What changed
| Property | Gossamer Condor | Surf / pump foil | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 29260 mm | 900 mm | -28360 mm | -96.9% |
| Root chord | 2862 mm | 150 mm | -2712 mm | -94.8% |
| Tip chord | 1431 mm | 76 mm | -1355 mm | -94.7% |
| Sweep parameter | 11.711 | 8.553 | -3.158 | -27.0% |
| Dihedral | 3.00° | -1.50° | -4.50° | -150.0% |
| Tip twist | 0.00° | -2.00° | -2.00° | — |
| TE thickness | 2 mm | 0 mm | -1 mm | -83.3% |
| Sections | 40 | 30 | -10 | -25.0% |
| Tip cap peak (chord fraction) | 0.500 | 0.450 | -0.050 | -10.0% |
| Tip cap reach | 0.200 | 0.350 | +0.150 | +75.0% |
| Derived | ||||
| Aspect ratio | 12.914 | 7.241 | -5.674 | -43.9% |
| Area | 66293551 mm² | 111865 mm² | -66181686 mm² | -99.8% |
| Taper | 0.500 | 0.507 | +0.007 | +1.3% |
| MAC | 2358 mm | 128 mm | -2230 mm | -94.6% |
| Sections | ||||
| Root section | l7769 | a18 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 2712 mm | |||
| Chord deviation (RMS) | 2185 mm | |||
| Twist deviation (max) | 2.00° | |||
| Dihedral deviation (max) | 779 mm | |||
| Tip cap deviation (max) | 14773 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 — “Gossamer Condor” integrates to CL 0.112 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.539 (0.21×); “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×). 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 (air, water (sea))
data
| V (kt) | Gossamer Condor | Surf / pump foil |
|---|---|---|
| 7.74 | 17.21 | 14.72 |
| 7.90 | 18.16 | 15.44 |
| 8.57 | 22.19 | 18.41 |
| 8.75 | 22.79 | 19.18 |
| 9.41 | 25.08 | 21.39 |
| 9.60 | 25.71 | 22.03 |
| 10.24 | 27.83 | 23.65 |
| 10.45 | 28.46 | 24.17 |
| 11.07 | 30.35 | 25.03 |
| 11.30 | 30.86 | 25.35 |
| 11.91 | 32.21 | 25.68 |
| 12.15 | 32.39 | 25.81 |
| 12.74 | 32.83 | 25.85 |
| 13.00 | 32.66 | 25.87 |
| 13.57 | 32.27 | 25.67 |
| 13.85 | 31.85 | 25.57 |
| 14.41 | 31.02 | 25.17 |
| 14.70 | 30.54 | 24.96 |
| 15.24 | 29.65 | 24.44 |