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DRAG COEFFICIENTS OF SPHERES FALLING IN DILUTE AQUEOUS SOLUTIONS OF LONG-CHAIN MACROMOLECULES.
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
The drag coefficients of spheres falling in dilute aqueous solutions of long-chain macromolecules were investigated over a range of Reynolds numbers based on the viscosity of water from 800 to 70,000. Solutions used had polymer concentrations of 100 to 1000 weight parts per million of three grades of Polyethylene Oxide, WSR-35, WSR-205 and WSR-N-3000, and concentrations of 10 to 1000 weight parts per million of WSR-301. Reductions in drag were observed in only the solutions of the two higher molecular weight polymers, and then only at Reynolds numbers greater than 10,000. For all concentrations of WSR-301, the drag decreased with increasing Reynolds number and for a given Reynolds number the drag was minimized at a concentration of 100 wppm. Author