The Influence of the Chemical Nature of Polymers on Their Drag Reduction Characteristics
The Influence of the Chemical Nature of Polymers on Their Drag Reduction Characteristics

Author: Moshe A. Frommer

Publisher:

Published: 1973

Total Pages: 35

ISBN-13:

DOWNLOAD EBOOK

Effects of molecular characteristics of water soluble polymers on drag reduction were investigated by studying changes in the drag reduction efficiency of long chain vinylic polymers, having an identical polymeric backbone, with changes in the chemical nature of their functional groups; and studying the effect of conformational changes of a simple polymer on its drag reduction efficiency by changing the pH or adding salt to the solution. The polymers studied were polyacrylamide, hydrolized polyacrylamide, polyacrylhydrazide and polystyrene sulfonate. (Modified author abstract).

Effect of Molecular Weight and Segmental Constitution on the Drag Reduction of Water Soluble Polymers
Effect of Molecular Weight and Segmental Constitution on the Drag Reduction of Water Soluble Polymers

Author: Gail T. Pruitt

Publisher:

Published: 1965

Total Pages: 125

ISBN-13:

DOWNLOAD EBOOK

Tube flow data on some 16 polymers indicate that drag reduction is a function of molecular contour length, segmental side groups, concentration, pipe diameter and Reynolds number. The maximum drag reduction actually obtained with any drag reducing polymer is approximately 80% of that which would be obtained if completely laminar flow was maintained. A relationship that correlates drag reduction, concentration and molecular dimensions is suggested for a constant Reynolds number and pipe size. It infers that a critical concentration of polymer exists, below which no drag reduction occurs. Also for some given concentrations and pipe size a critical velocity exists below which no drag reduction occurs. Rheological data for two polymer solutions are presented in terms of elastic energy. (Author).

Development of a Fluid Concentrated Dispersion of a Water-soluble Polymer Capable of Reducing the Friction of Water Under Turbulent Conditions
Development of a Fluid Concentrated Dispersion of a Water-soluble Polymer Capable of Reducing the Friction of Water Under Turbulent Conditions

Author: North Star Research and Development Institute (Minneapolis, Minn.)

Publisher:

Published: 1966

Total Pages: 24

ISBN-13:

DOWNLOAD EBOOK

A method of using water soluble polymers to reduce the friction caused by turbulent flow of water was investigated by employing fluid, concentrated dispersions (slurries) of polymer in nonsolvent carriers. Prototype 10-percent slurries of various drag reducing polymers were injected into flowing turbulent water streams, and friction reductions as great as 49 percent were noted with mixing times as short as 1.5 seconds. Higher friction reduction was achieved at somewhat longer times. The system appears to be a very promising approach to applying drag reducing polymers to the waters around a ship hull. (Author).

Shear-Resistant Drag Reduction Polymers. Part 1. Molecular Investigations of Polymer Drag Reduction and the Development of Laboratory Screening Methods
Shear-Resistant Drag Reduction Polymers. Part 1. Molecular Investigations of Polymer Drag Reduction and the Development of Laboratory Screening Methods

Author: Oh-Kil Kim

Publisher:

Published: 1990

Total Pages: 23

ISBN-13:

DOWNLOAD EBOOK

Polyacrylic acid (PAA) is a water-soluble polymer that is well suited for studying molecular influences on polymer drag reduction behavior since its polymer chain conformation and size in water are extremely sensitive to solution conditions. Effects of PAA molecular weight and solution factors such as pH and water quality were investigated. Solution pH is the most important factor governing conformation of polyelectrolytes such as PAA; a higher pH (leading to size expansion) gives a polymer drag reduction. As is known, molecular weight is an intrinsic factor in polymer drag reduction. Another critical factor for PAA drag reduction is water quality, since mineral ions present in water can induce collapse of the polymer molecules and subsequently, the drag reduction becomes null. However, in mineral-free water (obtained by either demineralization or chemical treatment), PAA drag reduction is remarkable.(jes).