COMPARISON OF SEMISPAN AM) FULL-SPAN TESTS OF A 47.5 ' SW"m WING KITH SYMMEZRICAL CIRCuLAR4RC SECTIONS AND EAVING DROOPED-NOSE FLPSS,

I In order t o help evaluate the general. va l id i ty of the semispan wing tes t ing technique in the Iangley full-scale tunnel, an investiga-t ion was conducted t o compare the characterist ics of a fill-span and a semispan highly swept wing. Wing surface pressure and force measure-ments were obtained on a semispan model of a 47.5 ' sweptback w i n g for which full-span data were available. The wing had symmetrical biconvex taper ra t io of 0.5, and no geometric dihedral or twist. The configura-tions investigated included the basic w i n g, the wing with a drooped-nose f lap and a trailing-edge flap deflected both alone and i n combfna-tion, and the basic w i n g with a deflected aileron. The data were obtained a t a Reynolds nwnber of 4.2 x 10 6 and a mch number of 0.07. a i r fo i l sec t ions 10 percent thick and had an aspect ratio of 3.5, a The results indicate close agreement between the full-span- and semispan-wing data and demonstrate the acceptability of the semispan method of t es t lng for wings similar t o the one investigated. Slightly higher maximum lift coefficients a t a higher angle of at tack and a more negative pitching tendency over a large part of the lift range were observed for the semispan wing. These differences in the wing charac-t e r i s t i c s are believed to be due t o a 106s of l i f t near the r o o t of the semispan wing and to a shift of the leadingedge separation-vortex origin from the wing apex caused by the interference of the reflection-plane boundary layer