Equilibrium of the Glider (3-D Incompressible Flow)

14.1.3.1 Glider Effective Aspect Ratio

As a glider (engine off), the glider has the following lift and moment coefficients in terms of the geometric angle of attack a (rd) and tail setting angle tt (rd):

Cl (a, tt) — 5.3a + 1.56 + 0.5tt
Cm,0 (a, tt) — —1.7a — 0.43 — 0.45tt

Find the effective aspect ratio AR of the glider (wing+tail), assuming ideal loading.

14.1.3.2 Equilibrium Angle of Attack

Find aeq (tt) for the glider, given that ^ — 0.29. Hint: the equilibrium of the moment corresponds to

x

, tt) + CL (aeq

lref

Find the angle of attack aeq and the corresponding setting angle of the tail tt for Cl — 1.9.

14.1.3.3 Landing Speed

At sea level, p — 1.2 kg/m3, g — 9.81 ms-2, find the landing speed, given that the total mass m — 15 kg, the maximum lift coefficient (CL )max — 1.9 corresponding to the reference area Aref — 0.68 m2. Hint: use the equilibrium equation in the direction perpendicular to the flight path.