Page 200 - Aerodynamics for Engineering Students

Two-dimensional wing theory 183

Fig. 4.15
whence cos q5 = 2F - 1. Evaluating the integral

i.e. since all angles are small h/F = tanq N q, so

A0 = -(1 -:)q (4.49)

Similarly from Eqn (4.42)

(4.50)
Thus
2 sin q5 sin 24
AI =- q and A2 =- rl
7r 7r
The distribution of chordwise circulation due to flap deflection becomes
1
1 +cos8 q5 ~+cosS+$~S;~~~~
k = 2Ua sinno q (4.51)
sin e +2U[(l-;) sin 0
and this for a constant incidence a is a linear function of q, as is the lift coefficient,
e.g. from Eqn (4.43)

giving
CL = 27ra + 2(7r - q5 + sin q5)q (4.52)

Likewise the moment coefficient CM, from Eqn (4.44) is