Location of aerodynamic center

Induced drag.

If the leading edge is supersonic, then or , where - for the flat wing. At the subsonic leading edge it is necessary to take into account the sucking force. In this case , or approximately

; ; ; (6.22)

Fig. 6.17.

Where - factor of sucking force realization (refer to item 6.2);

and - parameters of a triangular wing, which leading edge coincides to the leading edge of considered wing (fig. 6.17).

Generally, there is a dependence , in which the influence of taper is essential in difference from the characteristics and . Location of aerodynamic center tend to the position of the center of mass of a figure presenting the wing plan form with increasing of reduced aspect ratio. In particular, for wings with unswept edges of the tapered plan form we have

. (6.23)

The reduced formula can be used already at :

(For a rectangular wing - , ;

for a triangular wing - , , ).

Note: At calculation of the aerodynamic characteristics of the complex plan form wings (curved edges or the edges with a fracture) approximate methods replacing variables spanwise , ,... by their mean values are used together with precisely numerical calculations of a particular wing.

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