(642c) Scaleout of Pipeline Drag Reduction by Wall-Injected Polyox to a Flat Plate Boundary Layer

Turbulent drag reduction by wall-injected Polyox solutions was studied by simultaneous axial pressure profile and flow visualization measurements at Reynolds numbers from 50000 to 100000 in a transparent test pipe of ID 16 mm and L/D 430. Friction factors for deionized water solvent adhered to the Prandtl-Karman law for fully-developed turbulent flow in smooth pipes. The P309 Polyox, of MW ~ 8x106 with Nbb ~ 0.5x106 backbone chain links, was injected as a concentrated solution Cinj =1000 wppm through 6 equi-spaced circumferential ports at friction-normalized injection velocities Vinj+ ~ 1