Accession Number : ADA181042

Title :   Injection of Drag Reducing Additives Into Turbulent Water Flows. Mixing Experiments and Newtonian Burst Frequency.

Descriptive Note : Annual rept. 1 Mar 86-28 Feb 87,

Corporate Author : PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING

Personal Author(s) : Tiederman,William G ; Walker,David T ; Bustetter,C D

PDF Url : ADA181042

Report Date : Apr 1987

Pagination or Media Count : 46

Abstract : This report first describes two-component velocity measurements and mean concentration measurements in the region where a concentrated, drag-reducing, additive solution mixes with a channel flow of water. The additive is introduced through flush mounted, angle injectors that initially place the solution next to the wall. Near the injectors, the mean concentration profiles contain very sharp gradients that separate high concentration wall regions from a low concentration core. When the central core is void of additive the root-mean-square of the normal velocity fluctuation, v', and the Reynolds shear stress, rho uv, are unaffected in this core region. These two quantities are significantly lower in the high concentration, wall region compared to their corresponding water flow levels. Further downstream, where the additive is present across the entire channel v' and rho uv are reduced across the entire channel. This indicates that once the additive has mixed beyond the wall region in even small quantities the structure of the flow is altered everywhere. The second portion of the report describes single component laser velocimeter measurements in a Newtonian channel flow where the Reynolds number was 50,000. The purpose of these measurements was to deduce the average time between bursts at this relatively high Re. Results show that the time between bursts when scaled with wall shear velocity and kinematic viscosity has a constant value of 90 for the Re range 9,400 to 50,000.

Descriptors :   *ADDITIVES, *DRAG REDUCTION, *CHANNEL FLOW, ANGLES, BURST TRANSMISSION, CONCENTRATION(COMPOSITION), CORES, FLOW, FREQUENCY, GRADIENTS, HIGH RATE, INJECTORS, LEVEL(QUANTITY), MEASUREMENT, MIXING, MOMENTUM TRANSFER, QUANTITY, REYNOLDS NUMBER, SHARPNESS, SHEAR PROPERTIES, SHEAR STRESSES, TURBULENT FLOW, VARIATIONS, VELOCITY, VISCOSITY, WALLS, WATER, WATER FLOW

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE