Circulation measurements about the tip of an airfoil during flight through a gust

Kuethe, Arnold (Daniel Guggenheim Airship Institute, Akron, Ohio)
naca-tn-685
February 1939


Measurements were made of the circulation about the rectangular tip of a short-span airfoil passing through an artificial gust of known velocity gradient. A Clark Y airfoil of 30-centimeter chord was mounted on a whirling arm and moved at a velocity of 29 meters per second over a vertical gust with a velocity of nearly 7 meters per second. Flow angles were measured with a hot-wire apparatus. The rate at which the lift at the tips of a wing entering a gust is realized was found to be in satisfactory agreement with that predicted on the basis of the two-dimensional theory of von Karman and Sears.

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