SPHERE DRAG MEASUREMENTS IN AN AEROBALLISTICS RANGE AT HIGH VELOCITIES AND LOW REYNOLDS NUMBERS
ARO INC ARNOLD AFS TN
Pagination or Media Count:
The drag coefficients of spheres for Re2 10 to the 4th have been measured in the velocity range 3000 V sub infinity 21,000 ftsec with an accuracy of approximately or - 1.5 percent. In addition, successful techniques for manufacturing and launching ultralightweight spheres densities approaching 1 lbcu ft have resulted in the ability to measure sphere drag coefficient in the velocity range 3000 V sub infinity 12,000 ftsec and Reynolds number range 3 Re2 10 to the 6th, with an accuracy of approximately or - 4 percent. This wide range of operating conditions has made it possible to study the initial departures of sphere drag coefficient from the high Reynolds number, continuum level and also to make measurements at free-stream Knudsen numbers approaching 1.0. The results of the tests at the low Reynolds numbers are shown to be consistent with the results obtained in other low- density, hypersonic-flow facilities.
- Fluid Mechanics