TRANSONIC INVESTIGATION OF THE STATIC LONGITUDINAL AERODYNAMIC CHARACTERISTICS OF LOW-ASPECT-RATIONWING-BODY CONFIGURATIONS AT ANGLES OF ATTACK AROM 0 DEG TO 90 DEG

An investigation has been conducted in the Langley transonic blowdown tunnel to determine the effects of wing planform and other geometric parameters on the static longitudinal aerodynamic characteristics of winged vehicles suitable for reentry.Wing leading-edge radius and wing lower surface contour were also varied for several of the configurations during the investigation.The tests were made at Mach numbers of about 0 .8,1.01, and 1.18 for angles of attack that generally varied from about _4 0 to 91 0 .The results of the investigation indicate that, at a given test Mach number, planform variation for the basic models had a consi derable effect on lift-curve slope at an angle of attack of 0 0 but had essentially no effect on maximum lift coefficient, lift-curve slope at an angle of attack of 90 0 , or maximum drag coefficient.The values of maximum lift-drag ratio for the circle model varied between 2.5 and 3.0 whereas those of the other basic planforms generally varied between 3 and 4. The basic planforms were longitudinally unstable below the angle of attack at which maximum lift was obtained and longitudinally stable above this angle of attack, the moment reference point being located at the centroid of planform area of each planform.Changing the leading edge of the 65 0 triangular model from cylindrical to square caused higher maximum drag and, generally, small positive increments in pitching moment through the test angle-of-attack range.Contouring the wing lower surface of the basic ellipse model to form the model designated as ellipse (convex) caused positive increments in pitching moment, decreases in lift coefficient and maximum drag coefficient, and small changes in stability.Contouring the wing lower surface of the 75 0 model to form a trihedron model caused large negative increments in pitching-moment coeffiCient, an increase in lift coefficient below and a decrease in lift coefficient above an angle of attack of 20 0 , and an increase in drag coefficient below an angle of attack of about 50 0 • The trihedron model had the lowest maximum lift-drag ratio of the configurations tested.A b CD max , 2 aspect ratio, wing span axial-force coefficient, Axial force drag coefficient, maximum drag coefficient CD min , CLa.,oo Cltx.,9