An elliptical wing has aspect ratio $AR = 6.0$. If the wing operates at a lift coefficient $C_L = 0.6$, what is the induced drag coefficient $C_{Di}$? (Take $\pi \approx 3.1416$, round to four decimal places).

Answer Key:

0.0191

### Solution: For an elliptical lift distribution, span efficiency factor $e = 1.0$. Induced drag: $C_{Di} = \frac{C_L^2}{\pi AR} = \frac{0.6^2}{\pi \times 6} = \frac{0.36}{6\pi} = \frac{0.06}{3.1416} \approx 0.0191$. Correct: 0.0191 (range 0.0185 to 0.0195).

← Prev Question Next Question →