<DOC>
<DOCNO>
683
</DOCNO>
<TITLE>
the use of conical camber to produce flow attachment at the leading
edge of a delta wing and to minimize the lift-dependent drag at sonic
and supersonic speeds .
</TITLE>
<AUTHOR>
smith,j.h.b. and mangler, k.w.
</AUTHOR>
<BIBLIO>
r.a.e. rep. aero. 2584. arc 19,961, september 1957 .
</BIBLIO>
<TEXT>
in an attempt to avoid flow separation at the leading edge of a thin
delta wing with subsonic leading edges, an attachment line is prescribed
 there . this is done by requiring the load, as predicted by attached
flow theory, to vanish along the leading edge at the design lift
coefficient . for sonic speed, a complete account of this flow is given
in terms of slender wing theory and the load distributions corresponding
 to arbitrary conical camber are calculated . for supersonic speeds
load distributions arising in the slender wing theory are considered and
 the corresponding conical camber distributions are found by linearized
theory . the lift-dependent drag for a given lift is then minimized with
 respect to the coefficients of a linear combination of these load distributions
. it is found that the lift-dependent drag factor for these
conically cambered wings approaches the value it takes for the attached
flow/in which leading edge suction occurs/past the uncambered wing at
the same mach number, as more terms are included in the linear combination
. however, when the leading edge is almost sonic an appreciable
reduction is predicted . the corresponding load distributions and wing
shapes are calculated and drawn . the optimum shapes for a fixed number
of terms resemble flat plates drooped downwards near their edges, so
that the localised leading edge suction is replaced by a distributed
force on a forward-facing surface, producing an effect of similar
magnitude .
</TEXT>
</DOC>
