ESDU 87031:2013

ESDU 87031 involves estimating separately two contributions to
the zero-lift angle. One is due to camber, taken as that
corresponding to the wing-root section and assumed constant across
the span. The other is due to the combined effects of geometric
twist and of camber-dependent twist associated with spanwise camber
changes from that at the root. The method applies to a wide range
of cambered and twisted straight-tapered wings, provided that the
local effective twist is less than about 10 degrees and the flow is
fully attached and subsonic at zero-lift. It can be applied to
wings with cranked or curved edges using an "equivalent wing
planform" as defined in ESDU 76003. The method correlates
wind-tunnel test data drawn from a wide range of sources in the
literature to within degrees. Illustrations of typical uses for the
method are given in the form of four worked examples. A computer
program of the method is provided as ESDUpac A8731 and described in
an appendix.