Interference-free measurements of the subsonic aerodynamics of slanted-base ogive cylinders

Drag, lift, pitching moment, and base-pressure measurements have been made, free of support interference, on a range of slanted-base ogive cylinders, using the NASA Langley Research Center 13-in. magnetic suspension and balance system. Test Mach numbers were in the range 0.04-0.2. Two types of wake flow were observed, a quasisymmetric turbulent closure or a longitudinal vortex flow. Aerodynamic characteristics differ dramatically between the two wake types. Drag measurements are shown to be in agreement with previous tests. A hysteretic behavior of the wake with varying Reynold's number has been discovered for the 45-deg base. An interaction between forebody boundary-layer state and wake flow and base pressures has been detected for higher slant angles. CL CD CM ReD SCR Nomenclature = lift coefficient, based on frontal area = drag coefficient, based on frontal area = pitching moment coefficient, based on frontal area and half length of 0-deg base model = Reynold's number, based on model diameter = silicon controlled rectifier