Wind-tunnel tests of a Clark Y wing having split flaps with gaps

Wenzinger, Carl J
naca-tn-650
May 1938


Tests were made of the Clark Y wing having split flaps with a gap between the flap and the lower surface of the wing. Lift, drag, and pitching moments were measured for the wing with three different sizes of flap. It was found that any gap between the flap and the wing reduced the lift, the drag, and the pitching moments, but that the center-of-pressure movement and the ratio of lift to drag were little affected.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1938/naca-tn-650.pdf