Induced Downwash in Manoeuvre

The simplest loading that will contribute to roll is mode 2, which is antisymmetric and does not contribute to lift as any mode An, n > 2. The mode 2 circulation and induced downwash are given by

r2[y(t)] = 2UbA2 sin2t sin 2t

wW2 [y (t)] = —2U A2 = —4U A2 cos t

sin t

Given that y(t) = -| cos t, 0 < t < n, the last relation reads

y

Ww2 (У) = 8UA2

b

This is represented in Fig. 15.24.

15.6.2.3 Induced Drag in Manoeuvre

The induced drag is given by

ideal ^1 + 2 ^^ = (CDt)ideal ^1 +

The increase in induced drag is 2%.

Fig. 15.24 Mode 2 loading for manoeuvre