Published online by Cambridge University Press: 04 July 2016
The effect of trailing edge extensions was tested for the twodimensional Göttingen 797 and Wortmann FX 63-137 aerofoil sections with smooth surfaces at chord Reynolds numbers from 3 x 105 to 1 x 106 in the 8ft x 6ft low speed wind-tunnel at the Cranfield Institute of Technology. Force measurements were made on the basic aerofoil sections and with extension plates of 10% and 20% chord set tangential to the upper surface at the trailing edge. It was verified that the addition of an extension plate effectively brings about an increase of maximum lift coefficient and an improved lift-to-drag ratio for the Göttingen aerofoil section. However, the effect of the extension plate was small on the Wortmann aerofoil section.
Permanent address: Department of Mechanical Engineering, School of Science and Technology, Meiji University, 1-1-1, Higashi-Mita, Tama-ku, Kawasaki 214, Japan.