• Version
• 195 Downloads
• 835.24 KB File Size
• 1 File Count
• April 23, 2016 Create Date
• April 23, 2016 Last Updated

National Advisory Committee for Aeronautics, Technical Notes - Rolling, Yawing, and Hinge Moments Produced by Rectangular Ailerons

In this report the studies of the characteristics of
rectangular ailerons described in references 1, 2, and 3
are summarized in the form of_empirical equations which
relate the aileron dimensions and displacements to the
rolling, yawing, and hinge moments for pitch angles of 0°
and 12 degrees, corresponding to angles of attack of the
wings of 40 and 16° degrees, respectively. The report also
includes a comparison of the results obtained by computa-
tion from measurements on a single aileron, with those
obtained by using two ailerons mounted on opposite wings
and displaced simultaneously. Satisfactory agreement is
shown between these methods. Rectangular airfoils (10-
inch chord by 60—inch span) having the Clark Y and U.S.A.
27 profiles and mounted on a model fuselage were used
throughout the investigation.
The work was conducted in the 10—foot wind tunnel of
the Bureau of Standards with the cooperation of the Aero—
nautics Branch of the Department of Commerce and the Na—
tional Advisory Committee for Aeronautics.
The rolling and yawing moments arising. as a result of
aileron displacement for a given attitude of an airplane
are dependent primarily on three factors: (1) the magni—
tude of the displacement, (2) the size and shape of the
ailerons, and (3) the lateral position of the ailerons
with respect to the axis of the airplane. Further, it ap—
pears from a study of the available data that the corre—
sponding coefficients are approximately proportional to
the aileron angle and to simple functions of the aileron
chord and span. These relationships suggested the possi—
bility of expressing the moments in the form of empirical
equations suitable for purposes of preliminary design and
this has been done using data taken from references 1, 2,
and 3.
After the completion of the experimental work de—
scribed in these references, attention was called to the
work of Hartshorn, who pointed out from theoretical con—
siderations (reference 4), that the method of images, which
utilizes the half—span of the airfoil and a reflecting
plane, or any method which involves measurement on a sin-
gle aileron, may lead to incorrect conclusions when used
to determine the effects of the displacement of two ail~
erons on opposite wings.