A BROAD SURVEY OF FREE-FLIGHT RANGE MEASUREMENTS FORM THE FLOW ABOUT SPHERES AND CONES

摘要

Free-flight measurements of the flow about both non-ablating and ablating spheres, sphere-capped cylinders, and cones are reported. Included are radiometer measurements in the 0.2-5.5 micron band, image converter and schlieren photographs, microwave measurements of wake ionization, head-on radar cross-section measurements, backscatter radar cross-section measurements of turbulent trails, and measurements of precursor ionization. Radiation results for non-ablating spheres, the effect of contaminants, and a comparison between sphere and cone results are presented. The status of the head-on radar results which include anomalous absorption is discussed. Precursor ioniation ahead of non-ablating spheres was identified and attributed to photoionization. Comparative results of both schlieren and radar systems, which involve transition from laminar to turbulent flow and scattering from turbulent wakes are outlined. For cones, conditions cover velocities up to 22,000 ft/sec and pressures up to 150 mm hg, while for spheres, velocities range up to 24,000 ft/sec and pressures up to 300 mm hg. (Author)