Settling Characteristics of Discs and Cylinders

Abstract

The settling characteristics of large non-spherical particles in the form of discs have been studied. The coefficient of resistance has been determined for cylinders of aspect ratio from 0. 25:1 to 5. 0:1. Cylinders of aspect ratio less than 1:1 showed agreement with previous results, when the coefficient of resistance was plotted against sphericity. Cylinders with aspect ratio greater than 1:1 were found to have a constant coefficient of resistance for increasing aspect ratio. When plotted against sphericity, the value of this coefficient remained constant until the particle was large enough for the wall effect to be observed. The coefficient of resistance was found to increase for aspect ratios decreasing below 1:1 and again for aspect ratios increasing above 4:1. A relationship between the Reynolds and Galileo numbers has been established. Ga equals 5. 50 Re**1**. **7**8.