Drag coefficients of spheres in poly(ethylene oxide) solutions

Setting of Spheres in Drag-Reducing Polymer Solutions

“…The difference of individual velocities from the average value did not exceed 3%, and this is mainly attributable to the fact that, at the The measured sphere velocities exhibited a dependence on cylinder diameter which, over the range of cylinder diameters used in this investigation, could be distinguished from the experimental scatter of the data. Our observations in this regard are, therefore, not in accord with those of Sanders (1967) who, having used a limited range of cylinder diameters (3 and 6 inches), concluded that the wall effect was negligible. Our sphere velocities were corrected for wall effect by extrapolation of velocity against reciprocal cylinder diameter to infinite diameter.…”

“…Several reports on the settling of rigid spheres in dragreducing dilute polymer solutions have appeared in the literature (Ruszczycky, 1965;Sanders, 1967; White, 1966). The problem is of interest from both the practical and experimental viewpoints.…”

Some cavitation experiments with dilute polymer solutions

“…Much of this, however, is speculative and a complete explanation must await a detailed exploration of the exact nature of the disturbances, their formation and growth. It does not seem unreasonable, however, to suggest that these instabilities may also occur in comparable fully-attached flows, such as those of Sanders (1967). If this is the case the cavities may have been used as a very rough 'flow visualization ' device.…”