<DOC>
<DOCNO>
225
</DOCNO>
<TITLE>
elliptic cones alone and with wings at supersonic speeds .
</TITLE>
<AUTHOR>
jorgensen,l.h.
</AUTHOR>
<BIBLIO>
naca tn4045,1957
</BIBLIO>
<TEXT>
  to help fill the gap in the knowledge
of aerodynamics of shapes
intermediate between bodies of revolution
and flat triangular wings, force
and moment characteristics for elliptic
cones have been experimentally
determined for mach numbers of 1.97 and
sectional axis ratios from 1 through 6
and with lengths and base areas
equal to circular cones of fineness
ratios 3.67 and 5 have been studied
for angles of bank of 0 and 90 .
elliptic and circular cones in combination
with triangular wings of aspect
ratios 1 and 1.5 also have been considered
.  the angle-of-attack range
was from 0 to about 16, and the
reynolds number was 8x10, based on
model length .  in addition to the
forces and moments at angle of attack,
pressure distributions for elliptic
cones at zero angle of attack have been determined .
  the results of this investigation
indicate that there are distinct
aerodynamic advantages to the use of
elliptic cones .  with their major
cross-sectional axes horizontal, they
develop greater lift and have higher
lift-drag ratios than circular cones
of the same fineness ratio and volume .
in combination with triangular wings
of low aspect ratio, they also develop
higher lift-drag ratios than circular
cones with the same wings .  for
winged elliptic cones, this increase
in lift-drag ratio results both from
lower zero-lift drag and drag due to
lift .  visual-flow studies indicate
that, because of better streamlining
in the crossflow plane, vortex flow
is inhibited more for an elliptic cone
with major axis in the plane of the
wing than for a circular cone with the
same wing .  as a result, vortex
drag resulting from lift is reduced .
shifts in center of pressure with
changes in angle of attack and mach
number are small and about the same
as for circular cones .
  comparisons of theoretical and
experimental force and moment characteristics
for elliptic cones indicate
that simple linearized (flat plate)
wing theory is generally adequate even
for relatively thick cones .  zerolift
pressure distributions and drag
can be computed using van dyke's
second-order slender-body theory .
for winged circular cones, a modification
of the slender-body theory of
naca rep. 962 results in good agreement
of theory with experiment .
</TEXT>
</DOC>
