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National Advisory Committee for Aeronautics, Research Memorandum -  CoInvestigation of the Characteristics of a High Aspect Ratio Wing in the Langley 8' High Speed Tunnel

Investigation of the characteristics of a Wing
with an aspect ratio of 9;0 and an NACA.652-10 airfoil_.
section has_been-made at Mach numbers up to O,925.f'The.
wing’tested has a taper ratio of 2r5:1,0, no-twist,
dihedral, or“sweepback,'ahd‘ZOepercent—chord 57.5-percent-
semispan plain ailerons. _The results showed that serious
changes_in the normal-forCe characteristics'occurred when
the“Mach numberuwas increased_above-O.gh at angles of.
attack'betWeen'49:afid“100'andzabove.0. O at 0° angle Cf
attack; Becapsenof.small"outboard shifts in the lateral
center of load, the bending moment at the root for condi-
tions corresponding to a 5g pulleout at an altitude of
55,000 feet increased by approximately 5 percent when the
Madh number was increased from 0.77 to 0.90. When the,
Mach number was increased beyond 0.85 the negative pitChing
moments for the high angles of attack increased,_whereas
those for the low angles of attack decreased with a
resulting large increase in the negative slope of_the__
pitching—moment curves. A large increase-occurred in the
values of the drag coefficients for the range of lift
coefficients needed for level flight at an altitude-of-
55,000 feet when the Mach number was increased beyond a,
value of 0.80.

The wakes at a station 2‘82 root chords
behind the wingnquarterrchord line extended approximately
a chordiabove‘the'Wing chord line for the angles of attack
required to recover from high—speed dives at high'MaCh“
numbers.

The recent development of turbine~jet units of
relatively high thrust has made possible the
consideration of Jet-propelled airplanes with maximum
speeds greater than 500 miles-per heur. Until the preSent
time, however, very little information has been available
on the aerodynamic characteristics of the component parts
of an airplane designed to operate at_these high speeds.
In order to design such a high—speed airplane properly,
more information about these characteristics at high and
low speeds was needed.

The NACA has undertaken a broad research
program to Supply this additional information.
In conjunction with this program a-series of tests have
been made on a high-aspect-ratio wing in the Langley 8—foot
high—speed tunnel in order to determine the effects of
compressibility on the characteristics of such a wing at
:Mach numbers approaching unity. Included in the series
of tests were investigations of theqbasic wing character-
istics,‘aileron characteristics, effects of dive brakes
and a dive-recovery flap, and-downwash fluctuations, The
results of the first investigation are presented herein.
The results of the other-investigations are presented in
references 1, 2, and 5, respectively.