Question

The measured lift slope for a new airfoil is 0.0975 degree-1, with al=0 =-1.15º. Consider a finite wing using this airfoil, with AR of 10 and taper ratio of 0.6. Calculate the lift and induced drag coefficients for this wing at a geometric angle of attack of 9º. Also, find the span efficiency factor. Hint: See Eq. (5.70) and Fig. 5.20. Are the values of lift and induced drag coefficients reasonable?

Answer 1

. ao O. 0975 deg 1.702 x 10-3 rad AR = le 34 Taper ratio 'T 4 = 0.6 + Cr Geometric angle of attack + do go = 0.16 dec a ao ++/9. ftrar ) (145) a 1.702 X 103 | 1702 X 10-3 T x 10 (17076) o 1.702 X 103 CL = lift Coefficient

4 ax -3 lo 702 X 1o X 0.16 2.723 X 10" 4 Induced drag coefficient (² Las TAR 2.36 x 10 9 span officiency factors 1+ Cal E