Gossamer Condor — 96 ft of wing at 11 mphvsDownwind glide foil — high aspect reference front wing
root section l7769 → e818 · dihedral 3.00° → -2.50° · tip cap reach 0.200 → 0.400 · area 66293551 mm² → 121109 mm² · tip chord 1431 mm → 48 mm · span 29260 mm → 1240 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
- Downwind glide foil — high aspect reference front wing
What changed
| Property | Gossamer Condor | Downwind glide foil | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 29260 mm | 1240 mm | -28020 mm | -95.8% |
| Root chord | 2862 mm | 130 mm | -2732 mm | -95.5% |
| Tip chord | 1431 mm | 48 mm | -1383 mm | -96.6% |
| Sweep parameter | 11.711 | 9.717 | -1.994 | -17.0% |
| Dihedral | 3.00° | -2.50° | -5.50° | -183.3% |
| Tip twist | 0.00° | -2.50° | -2.50° | — |
| TE thickness | 2 mm | 0 mm | -1 mm | -86.7% |
| Sections | 40 | 30 | -10 | -25.0% |
| Tip cap reach | 0.200 | 0.400 | +0.200 | +100.0% |
| Derived | ||||
| Aspect ratio | 12.914 | 12.696 | -0.219 | -1.7% |
| Area | 66293551 mm² | 121109 mm² | -66172442 mm² | -99.8% |
| Taper | 0.500 | 0.369 | -0.131 | -26.2% |
| MAC | 2358 mm | 104 mm | -2254 mm | -95.6% |
| Sections | ||||
| Root section | l7769 | e818 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 2732 mm | |||
| Chord deviation (RMS) | 2210 mm | |||
| Twist deviation (max) | 2.50° | |||
| Dihedral deviation (max) | 794 mm | |||
| Tip cap deviation (max) | 14607 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×); “Downwind glide foil” integrates to CL 0.061 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.446 (0.14×). 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 | Downwind glide foil |
|---|---|---|
| 8.55 | 22.07 | 22.02 |
| 8.57 | 22.19 | 22.15 |
| 9.41 | 25.08 | 27.74 |
| 9.91 | 26.75 | 31.15 |
| 10.24 | 27.83 | 31.77 |
| 11.07 | 30.35 | 33.35 |
| 11.27 | 30.80 | 33.73 |
| 11.91 | 32.21 | 33.58 |
| 12.64 | 32.76 | 33.40 |
| 12.74 | 32.83 | 33.28 |
| 13.57 | 32.27 | 32.34 |
| 14.00 | 31.64 | 31.87 |
| 14.41 | 31.02 | 31.20 |
| 15.24 | 29.65 | 29.84 |