TESTS IN THE VARIABLE-DENSITY WIND TUNNEL OF THE N. A. C. A. 23012 AIRFOIL WITH PLAIN AND SPLIT FLAPS

Section characteridic ~ for uge in WI-W dem”gnare pre-wrded for the N. A. C. A. %7019 airfm”l with plain and split $aps of 90 percent wing chord at a value of the efec-tice Reynolds Number of about 8,000,000. The j?ap defections corered CLrange from 60 ° upward to 76 ° down-ward for the plain jlap and from neutral to 90 ° dmimward for the split jlap. The split &p was aerodynamically superior to the plain flap in producing high maximum lift ooe~”enta and in?wm”nglower proj?ledrag coe$m”ents at high lifi coefints