WER-26: Additional reflection plane tests of control devices on an NACA 23024 airfoil
Citation
Snyder, M.H., Wentz, W.H., and H.Cao. Additional Reflection Plane Tests of Control Devices on an NACA 23024 Airfoil. Wind Energy Report no.26. Wichita State University. Center for Energy Studies, 1985, 205 p.
Abstract
Reflection plane tests of the NACA 23024 airfoil were
conducted in the 7 x 10 ft wind tunnel to determine the effects
of various aileron hingeline positions and auxiliary
leading-edge and tip cap on effectiveness of ailerons used as
aerodynamic control of horizontal axis wind turbines. Primary
purpose of control is to slow or to stop the turning of a wind
turbine rotor, requiring negative torque. Negative torque of a
zero-pitch untwisted rotor requires negative chordwise suction
force over a wide range of angles of attack.
Tests of 30% chord aileron at -90 degrees angle of
deflection and with 10 and 20 percent chord deflector plates
were conducted at hingeline positions of XH = 75%, ZH = 10% and
XH = 80%, ZH = 14% chord. Tests were conducted with gaps
between the airfoil and the aileron at fully-open, half-open
and fully-closed positions. The auxiliary leading edge
"Sharp 4" and the wingtip cap were also examined. Wind tunnel
tests were conducted at Reynolds numbers of 0.6 and 0.9 million
which correspond to Mach numbers of 0.1 and 0.175,
respectively.
Results of the studies show that the aileron with a 20%
deflector plate at hingeline position of XH = 80%,
ZH = 14% chord produced largest negative chordwise suction
force for all angles of attack from -10 to 90 degrees.
It is recommended that ailerons of this type be tested on
a rotating blade.
Description
In the public domain. Prepared for
NASA - Lewis Research Center
under Grant NSG3277. General Release Date: February, 1987