Abstract:

The methods of many Data Items that predict the aerodynamics of wings and wing-body combinations assume a straight-tapered wing for the presentation of correlations in terms of the planform parameters, aspect ratio, sweep and taper ratio. This reflects their predominance in the database. However, the methods are often also applicable to wings with modest cranks and sawteeth, but implementation requires a suitable representation as an equivalent straight-tapered planform.

Addendum A of ESDU 76003 describes a geometric construction of such an equivalent wing. The concept has been employed as a standard procedure in numerous applications within the ESDU Aerodynamics Series and has proved satisfactory. Its employment is subject to the proviso that although the geometric construction can be applied to any multi-cranked wing, with or without sawteeth, it would be expected to be a reasonable representation aerodynamically only for wings where the leading-edge sweep is constant, or has only minor changes, over the greater part of the span and for conditions where the flow over the wing is fully attached.

This Data Item provides a computer program, ESDUpac A1023, that calculates the geometry of the equivalent wing.