Drela SuperGee II — a 1.5 m discus-launch glider, drawn to the planvsPiper J-3 Cub — a rectangular wing that works
root section ag455ct02r → usa35b · tip section ag47ct02r → — · area 218576 mm² → 16577850 mm² · tip chord 94 mm → 1545 mm · mac 151 mm → 1545 mm · te thickness 0 mm → 3 mm
units
These analyses are not directly comparable
- different trim loads (2 N vs 5396 N) — each wing is carrying a different weight
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Drela SuperGee II — a 1.5 m discus-launch glider, drawn to the plan
- Piper J-3 Cub — a rectangular wing that works
What changed
| Property | Drela SuperGee II | Piper J-3 Cub | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 1498 mm | 10730 mm | +9232 mm | +616.3% |
| Root chord | 183 mm | 1545 mm | +1362 mm | +744.3% |
| Tip chord | 94 mm | 1545 mm | +1451 mm | +1543.6% |
| Sweep parameter | 3.400 | 0.000 | -3.400 | -100.0% |
| Dihedral | 4.00° | 1.00° | -3.00° | -75.0% |
| TE thickness | 0 mm | 3 mm | +3 mm | +900.0% |
| Sections | 30 | 40 | +10 | +33.3% |
| Tip cap reach | 0.400 | 0.300 | -0.100 | -25.0% |
| Derived | ||||
| Aspect ratio | 10.266 | 6.945 | -3.321 | -32.4% |
| Area | 218576 mm² | 16577850 mm² | +16359274 mm² | +7484.5% |
| Taper | 0.514 | 1.000 | +0.486 | +94.7% |
| MAC | 151 mm | 1545 mm | +1394 mm | +919.9% |
| Sections | ||||
| Root section | ag455ct02r | usa35b | changed | — |
| Tip section | ag47ct02r | — | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 1451 mm | |||
| Chord deviation (RMS) | 1399 mm | |||
| Twist deviation (max) | 0.00° | |||
| Dihedral deviation (max) | 41 mm | |||
| Tip cap deviation (max) | 4925 mm | |||
Performance
CoefficientsDimensionless — how good the shape is, independent of size and speed.
Spanwise
withheld — “Drela SuperGee II” integrates to CL 0.056 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.371 (0.15×); “Piper J-3 Cub” integrates to CL 0.002 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.330 (0.01×). A loading that does not integrate back to its own wing’s CL is not a coarse curve, it is a wrong one.
air, ρ = 1.225 kg/m³
data
| CD | Drela SuperGee II | Piper J-3 Cub |
|---|---|---|
| 0.014 | 0.259 | 0.374 |
| 0.015 | 0.264 | 0.378 |
| 0.016 | 0.290 | 0.398 |
| 0.017 | 0.327 | 0.430 |
| 0.017 | 0.334 | 0.437 |
| 0.019 | 0.371 | 0.469 |
| 0.021 | 0.415 | 0.511 |
| 0.022 | 0.425 | 0.520 |
| 0.026 | 0.491 | 0.585 |
| 0.027 | 0.509 | 0.605 |
| 0.032 | 0.574 | 0.667 |
| 0.036 | 0.627 | 0.729 |
| 0.041 | 0.681 | 0.775 |
| 0.053 | 0.758 | 0.894 |
| 0.062 | 0.819 | 0.968 |