Awing with an elliptical planform is flying through sea-level air at a speed of 55 m/s. the wing is untwisted, has the same section from root to tip and its loading is w/s = 1000 n/m2 . the 2d lift curve slope is a0 = 5.7. the span of the wing is 15 m and the aspect ratio if 5. find, a) the sectional lift coefficient. b) the sectional induced-drag coefficient. c) the effective, induced and geometric angles of attack if l=0 = -2 degrees.

Explanation:

a.) To find Secrional liftSectional lift Coefficient

where Rho = 1.225Kg/m³ (density of air at sea level)

b.) To obtain the sectional induced coefficient:

C.) For the effective angle of attack ∝0

∝0 =

For induced angle of attack ∝i:

∝i=

For absolute angle of attack ∝a:

∝a = ∝0 - ∝i = 0.0947 - (-0.0343) = 0.1290 rad

For geometric angle of attack ∝g:

∝g = ∝a + ∝L given ∝L = -2°≅-0.0349 rad

= 0.1290-0.0349 = 0.0941rad

0.863333

86%

hope this

wavelength divides in half and speed stays the same.