Supersonic Linearized Theory (Mo > 1)
The wave drag coefficient (Cd)a=0 is given by
dx 16 ґв
c 3в Vc/
(Cd )a=0 = (f’+(X )f + (f ‘-(X ))"
as seen in class.
Hence the lift and wave drag coefficients are:
Cl (a) = — = 0.0403
16 /e2 4a2
Cd(a) = 3в U + IT = a0315
3в c) в
The lift and wave drag upper bounds for the fin are
L = 2 pV 2bc Cl = 106 N
D = 2pV2bc Cd = 82.9 N
15.3.1 Lifting Line Theory (3-D Inviscid Flow)
18.104.22.168 Induced Drag in Cruise The induced drag Di in (N) is given by
1 2 c2l
Di = – pV 2 5—– —
i Г neAR
1 1 pV2neb2
The equilibrium equation along the vertical axis during horizontal cruise in dimensional form (neglecting the lift of the tail) reads:
The drag penalty is = 0.21, i. e. a 21 % increase in induced drag.