Accession Number : AD0841115

Title :   DRAG OF CIRCULAR CYLINDERS IN DILUTE AQUEOUS SOLUTIONS OF POLY(ETHYLENE OXIDE) FOR FLOWS CHARACTERIZED BY LAMINAR BOUNDARY LAYER SEPARATION.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : McClanahan, Ted ; Ridgely, Philip Jay

Report Date : JUN 1968

Pagination or Media Count : 75

Abstract : Circular cylinders of diameters from 1/4 in. to 2 in. and length to diameter ratios of 5, 10, and 40 were towed by a whirling arm of 2 meter diameter in Polyox WSR-301 aqueous solutions of 10, 50, 100, and 200 wppm (weights part per million) concentration. Drag forces, measured with a strain gauge, ranged from 10 gm to 3,500 gm for velocities ranging from 15 cm/sec to 6 m/sec. In this way, drag coefficients were obtained for a Reynolds number range of 2000 to 200,000 (based on diameter and the kinematic viscosity of water). Drag reduction was obtained for Re > 10,000 with the amount of reduction increasing with increasing Reynolds number. The largest amount of drag reduction was measured in the 100 wppm solutions. Qualitative observations on vortex-shedding frequency and surface-wave reduction were also made. The hypothesis that the polymer produces drag reduction by displacing the separation point was strongly supported by these findings. (Author)

Descriptors :   *FLOW SEPARATION), (*CYLINDRICAL BODIES, DRAG), (*LAMINAR BOUNDARY LAYER, VISCOSITY, SOLUTIONS(MIXTURES), POLYMERS, EPOXY RESINS, REYNOLDS NUMBER, VORTICES, WATER, THESES.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE