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110 Wing
( x A , z A )
centerline
mean aero
center
(wing location)
panel p
aero center locus
inboard outboard
edge
edge
ηEp outboard panel edge, η = y/(b/2)
ηIp ηOp wing station
λIp λOp chord ratio, λ = c/cref cIp cOp chord
Λ p sweep (+ aft)
δ p dihedral (+ up)
x Ip aero center offset (inboard, + aft)
z Ip aero center offset (inboard, + up)
b p span (each side)
c p mean chord
S p area = 2b p c p
Figure 13-1. Wing geometry (symmetric, only right half-wing shown).
panel, yp = yp−1 + bp or yp = yp−1 + fbp(b/2); or from the next station and the span of the next panel,
yp = yp+1 − bp+1 or yp = yp+1 − f b(p+1)(b/2). The specification of panel spans and panel edges must
be consistent, and sufficient to determine the wing geometry. Determining the panel edges requires the
following steps.
a) Calculate the panel edges that are either at fixed values (input, or from width, or from hub
position) or at fixed stations; root and tip edges are known.
b) Working from root to tip, calculate the adjusted panel edge yp if panel span bp or ratio fbp
is fixed, and if previous edge yp−1 is known.
c) Working from tip to root, calculate the adjusted panel edge yp (if not yet known) if panel
span bp+1 or ratio f b(p+1) is fixed, and if next edge yp+1 is known.
At the end of this process, all edges must be known and the positions yp must be unique and sequential.
If this geometry is being determined for a known span, then there must not be a fixed panel span or span
ratio that has not been used. Alternatively, if the wing span is being calculated from the specification of
all panel widths, then the process must leave one and only one fixed panel span or span ratio that has not
been used. Since the wing span is to be calculated, each panel edge is known in the form yp = c0 +c1b/2.
Then the unused fixed panel span gives the equation (c0 + c1b/2)O − (c0 + c1b/2)I = bp (subscript O