Accession Number : AD0743053

Title :   The Torque and Turbulent Boundary Layer of Rotating Disks with Smooth and Rough Surfaces, and in Drag-Reducing Polymer Solutions,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD

Personal Author(s) : Granville,Paul S.

Report Date : APR 1972

Pagination or Media Count : 54

Abstract : The resisting torque of disks rotating in an unbounded fluid is analyzed on the basis of three-dimensional boundary-layer theory. Smooth and rough surfaces in ordinary fluids and in drag-reducing polymer solutions are considered. A general logarithmic relation is derived for the torque as a function of Reynolds number for arbitrary roughness and arbitrary drag reduction. Special formulas are obtained for smooth surfaces, fully rough surfaces, polymer solutions with a linear logarithmic drag-reduction characterization, and polymer solutions with maximum drag reduction. Relations are also obtained for boundary-layer parameters such as thickness, wall shearing stress, etc. (Author)

Descriptors :   (*DISKS, HYDRODYNAMICS), TURBULENT BOUNDARY LAYER, THREE DIMENSIONAL FLOW, DRAG, TORQUE, POLYMERS, SURFACE PROPERTIES, SURFACE ROUGHNESS, SHEAR STRESSES

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE