Accession Number : ADA217492


Title :   Investigation into the Mechanism of Polymer Thread Drag Reduction


Descriptive Note : Technical rept. 1 Dec 1988-30 Nov 1989


Corporate Author : PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING


Personal Author(s) : Smith, Ronald E ; Tiederman, William G


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a217492.pdf


Report Date : Jan 1990


Pagination or Media Count : 72


Abstract : This study investigated the mechanism of drag reduction that occurs when a long chain, high molecular weight polymer is injected along the centerline of a pipe with a concentration high enough to form a coherent unbroken thread. The objective of this study was to test the hypothesis that drag reduction is caused by the diffusion of polymer molecules from the thread into the near-wall region of the pipe. The objective was realized through the measurement of the polymer concentration in the near-wall region, the drag reduction and the radial location of the thread. The concentration was measured using a laser induced fluorescence technique where the polymer was marked with fluorescein dye. The experiments were conducted in a 3.18 cm diameter, clear acrylic pipe at Re = 40,000 using a 5000 ppm concentration solution of Separan AP 273 as the injectant. The drag reduction increased from zero at the point of injection to a maximum value about 200 diameters downstream of the injector.


Descriptors :   *DRAG REDUCTION , *POLYMERS , LASER INDUCED FLUORESCENCE , MOLECULES , MOLECULAR WEIGHT , SYNTHETIC FIBERS , PIPES , CHAINS , CONCENTRATION(COMPOSITION) , DIFFUSION , HYPOTHESES , POSITION(LOCATION) , INJECTION , ACRYLIC RESINS


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE