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National Advisory Committee for Aeronautics, Research Memorandum - Some Effects of Spoiler Height, Wing Flexibility, and Wing Thickness on Rolling Effectiveness and Drag of Unswept Wings at Mach Numbers Between 0.4 and 1.7

Rolling effectiveness and drag tests of-spoilers on unswept wings
have been conducted over the Mach number range from 0.h to 1.7 by the
Langley Pilotless Aircraft Research Division utilizing rocket—propelled
test vehicles in free flight. The wings which were of aspect ratio 3.7
were unswept and untapered, had thickness ratios of 3, 6, and 9 percent,
and covered a range of flexibilities., Full-span solid sharp—edge spoilers
were located at the 0.8—chord line.

Increasing the wing flexibility increased the rolling effectiveness
at subsonic speeds and decreased it at supersonic speeds. Increasing
the spoiler height increased the rolling effectiveness linearly near
M = 1.0 but the increase was nonlinear at the other speeds tested. The
rigid—wing rolling effectiveness of the 3-percent-thick wing, compared
to that of the 9—percent—thick wing, was lower at subsonic speeds, higher
at low supersonic speeds, and about the same at speeds above‘ M = 1.3.
The drag generally increased linearly with increased spoiler height
except at the lower supersonic speeds.

The Langley Pilotless Aircraft Research Division is conducting a
general investigation of spoiler—type devices for roll control. Refer-
ence 1 shows that the 0.8—chord spoiler location resulted in rolling per—
formance generally superior to that of the O.h-chord or 0.6—chord loca—
tions. The present tests were conducted to determine the effects of
spoiler height on rolling effectiveness and drag for the untapered and
unswept 9-percent—thick wings having full—span, solid, sharp-edge spoilers°
located at the 0.8—chord station. Additional tests at one spoiler height
were made with wings having 6-percent and 3—percent thickness ratios and
different.

A comparison is made of the rolling effectiveness loss due to wing
flexibility for a spoiler and an aileron, and the drag for a spoiler and
an aileron is presented for the case where both controls have the same
estimated value of rolling effectiveness.