Download or read book Dilute Solution Molecular Characterization and Drag Reducation Studies of High Molecular Weight Polyethylene Oxide written by Brian Dion Jones and published by . This book was released on 2001 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular weight distributions of two high molecular weight (M[subscript w]”1 million) polyethylene polymers, WSR-308 and WSR-301, were characterized with gel permeation chromatography (GPC) coupled with a multi-angle laser light scattering detector (MALLS). The M[subscript w] of the WSR-308 was found to be 5.10x106 g/mol with a molecular weight range from about 1 million g/mol to as high as 10 million g/mol. The M[subscript w] of the WSR-301 was found to be 3.16x106 g/mol with the lowest molecular weight about 400,000 g/mol while the highest molecular weight component may have been as high as 8 million g/mol. Attempts to measure the M[subscript w] of the two polymers using static light scattering (SLS) techniques proved to be difficult. In conjunction with these studies, drag reduction and shear degradation studies of the two polymers in water were also conducted. Solutions of the two polymers, ranging from 1 to 10 ppm including mixtures of the two, were tested in a pipe-flow apparatus to obtain friction factor and %DR data. In every case, the greater the concentration and/or the molecular weight of the polymer, the greater the drag reduction effects. Additionally, the higher molecular weight polymer and mixtures with a greater weight percentage of the higher molecular weight polymer were found to shear degrade less quickly than otherwise. A unique point along the maximum drag reduction asymptote (MDA) termed the "divergence point" was a focus of this study and an energy model based on frictional losses correlates well to the data. The correlation developed here relates the difference in frictional losses between the solvent by itself and the polymer solution directly to the mass concentration and molecular weight of the polymer. This frictional difference was proportional to the product of the mass concentration and molecular weight where both quantities were to approximately the first power.
Download or read book The Drag Reduction of Dilute Polymer Solutions as a Function of Solvent Power Viscosity and Temperature written by Paul Peyser and published by . This book was released on 1971 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The frictional drag reduction of high-molecular-weight polyethylene oxide and polystyrene solutions under turbulent flow conditions was studied as a function of temperature, solvent power, and solvent viscosity. A rotating disk apparatus was used to make the drag reduction measurements. For aqueous polyethylene oxide solutions, at concentrations well above that needed to produce maximum drag reduction, all drag reduction data reduced to a common curve when percent drag reduction was plotted against the Reynolds number for the flow. However, for polyethylene oxide solutions below this optimum concentration the drag reduction-versus-Reynolds number curves showed decreasing drag reduction with increasing temperature. The data are explained primarily in terms of the inverse temperature solubility characteristics of polyethylene oxide in water. The percent drag reduction of polystyrene in nonaqueous liquids was found to be greater in good solvents than in poor ones. It was also found that increases in solvent viscosity and decreases in temperature increased the percent drag reduction. The results are discussed in relation to the current drag reduction theories and are shown to be in opposition to Virk's theory. It is concluded from the data that drag reduction is very likely a function of a relaxation time phenomenon involving the polymer molecules and the flow system. The results also emphasize the importance of considering solvent power, viscosity, and temperature in the design of an efficient drag reduction system. (Author).
Download or read book Poly ethylene Oxide written by Frederick Eugene Bailey and published by . This book was released on 1976 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Correlation Between Friction Reduction and Molecular Size for the Flow of Dilute Aqueous Polyethylene Oxide Solutions in Pipes written by and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pipe-friction factors for dilute aqueous polyethylene-oxide solutions in pipes of nominal diameters of 1/4, 3/8, and 3/4 in. were measured over a two decade range of Reynolds numbers. In the transition region, the amount of drag reduction is dependent upon polymer concentration and wall shear stress as well as Reynolds number. For high Reynolds numbers, where the wall shear stress was high compared to the critical value, no diameter effect was noted. Intrinsic viscosity measurements, made on samples withdrawn from pipe flow, provided direct evidence that polymer degradation take place under flow conditions. Spectrographic measurements indicated that this degradation is mechanical (and not chemical). The relative volume of solution occupied by polymer molecules (represented by the volume of equivalent hydrodynamic spheres) is shown to be a dominant parameter governing the drag-reduction phenomenon for polyethylene-oxide solutions in pipe flow. It is further shown that the equivalent volume ratio may be used to normalize the pipe friction factors for various concentrations of different molecular-weight species of polyethylene-oxide. (Author).
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Naval Research Reviews written by and published by . This book was released on 1971 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report of NRL Progress written by Naval Research Laboratory (U.S.) and published by . This book was released on 1971 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rheology of Drag Reducing Fluids written by Aroon Shenoy and published by Springer Nature. This book was released on 2020-03-25 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains theoretical derivations and presents expressions for fluid and convective turbulent flow of mildly elastic fluids in various internal and external flow situations involving different types of geometries, such as the smooth/rough circular pipes, annular ducts, curved tubes, vertical flat plates, and channels. Understanding the methodology of the analyses facilitates appreciation for the rationale used for deriving expressions of parameters relevant to the turbulent flow of mildly elastic fluids. This knowledge serves as a driving force for developing new ideas, investigating new situations, and extending theoretical analyses to other unexplored areas of the rheology of mildly elastic drag reducing fluids.The book suits a range of functions--it can be used to teach elective upper-level undergraduate or graduate courses for chemical engineers, material scientists, mechanical engineers, and polymer scientists; guide researchers unexposed to this alluring and interesting area of drag reduction; and serve as a reference to all who want to explore and expand the areas dealt with in this book.
Download or read book Papers Presented at the Meeting written by American Chemical Society. Division of Polymer Chemistry and published by . This book was released on 1977 with total page 1562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1973 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Review Naval Research Laboratory Washington D C written by United States. Office of Naval Research and published by . This book was released on with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drag Reduction in Polymer Solutions written by American Institute of Chemical Engineers and published by . This book was released on 1973 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polyelectrolytes and their Applications written by A. Rembaum and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyelectrolytes and their Applications is the second volume in the series 'Charged and Reactive Polymers'. The important areas of polyelectrolyte applications, i.e., biomedicine, water purification, petroleum recovery and drag reduction, are pre sented along with discussions of the fundamental principles of polyelectrolyte chem istry and physics. This book should be of interest to scientists such as physicians, biochemists, polymer chemists and chemical engineers involved in applications of these materials. The first part of the book is devoted to the basic properties of polyelectrolytes in general, namely to the factors influencing the chain conformation of charged polymers in solution and to their counterion selectivity. It also contains methods of synthesis and new concepts of charge stabilized polymer colloids and of polyelectrolyte ca talysis. The second part describes recent information on the properties and biological effects of already well-known natural polyelectrolytes such as heparin and DNA and recently developed polymers such as pyran and polyionenes. The effects of poly anions and polycations on normal and transformed cells as well as on acetylcholine receptors follow. This part is of particular interest to scientists involved in biological research.
Download or read book Government Reports Announcements written by and published by . This book was released on 1972-04 with total page 1542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration Scientific and Technical Information Division and published by . This book was released on 1970 with total page 966 pages. Available in PDF, EPUB and Kindle. Book excerpt:
