Download or read book Polymeric Concentration Determined by Drag Reduction written by Jalna R. Zatko and published by . This book was released on 1981 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymeric Concentration Determined by Drag Reduction written by Jalna R. Zatko and published by . This book was released on 1981 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Polymer Concentration and Tube Diameter on Drag Reduction Resulting from High Molecular Weight Additives in Water written by Jerald Paul Peterson and published by . This book was released on 1970 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Polymer Concentration on Turbulent Drag Reduction written by Chung Yin Leung and published by . This book was released on 2011 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Molecular Weight and Segmental Constitution on the Drag Reduction of Water Soluble Polymers written by Gail T. Pruitt and published by . This book was released on 1965 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).
Download or read book Properties and Behavior of Polymers 2 Volume Set written by Wiley and published by John Wiley & Sons. This book was released on 2012-12-03 with total page 1605 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides comprehensive, up-to-date information on the physical properties of polymers including, viscoelasticity, flammability, miscibility, optical properties, surface properties and more. Containing carefully selected reprints from the Wiley's renowned Encyclopedia of Polymer Science and Technology, this reference features the same breadth and quality of coverage and clarity of presentation found in the original.
Download or read book Polymer Injection for Drag Reduction written by J. Paul Tullis and published by . This book was released on 1972 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viscous drag reduction caused by polymer injection into a developing turbulent boundary layer was investigated in a 12-inch I.D. hydraulically rough pipe. Pressure drop measurements were made in the first 200 diameters of the pipe. Velocity profile and concentration profile measurements were also taken. Drag reductions above 90 percent were realized in the inlet region for lower injection concentrations. For a given polymer injection rate, drag reduction in the inlet region was found to decrease with increasing injection concentration. (Author).
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 Polymeric Materials Encyclopedia Twelve Volume Set written by Joseph C. Salamone and published by CRC Press. This book was released on 1996-07-23 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Polymeric Materials Encyclopedia presents state-of-the-art research and development on the synthesis, properties, and applications of polymeric materials. This groundbreaking work includes the largest number of contributors in the world for a reference publication in polymer science, and examines many fields not covered in any other reference. With multiple articles on many subjects, the encyclopedia offers you a broad-based perspective on a multitude of topics, as well as detailed research information, figures, tables, illustrations, and references. Updates published as new research unfolds will continue to provide you with the latest advances in polymer science, and will keep the encyclopedia at the forefront of the field well into the future. From novices to experienced researchers in the field, anyone and everyone working in polymer science today needs this complete assessment of the state of the art. The entire 12-volume set will be available in your choice of printed or CD-ROM format.
Download or read book Drag Reduction of Turbulent Flows by Additives written by A. Gyr and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drag Reduction of Turbulent Flows by Additives is the first treatment of the subject in book form. The treatment is extremely broad, ranging from physicochemical to hydromechanical aspects. The book shows how fibres, polymer molecules or surfactants at very dilute concentrations can reduce the drag of turbulent flow, leading to energy savings. The dilute solutions are considered in terms of the physical chemistry and rheology, and the properties of turbulent flows are presented in sufficient detail to explain the various interaction mechanisms. Audience: Those active in fundamental research on turbulence and those seeking to apply the effects described. Fluid mechanical engineers, rheologists, those interested in energy saving methods, or in any other application in which the flow rate in turbulent flow should be increased.
Download or read book Drag Reduction and Diffusion Accompanying Thin Slit Injections of a Drag Reducing Polymer on a Flat Plate at High Reynolds Numbers written by Daniel H. Fruman and published by . This book was released on 1972 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure of Turbulence and Drag Reduction written by Albert Gyr and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1976 a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington . However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and by direct manipulation of the walls (compliant walls and heated surfaces) were discussed. In the meantime it became evident that drag reduction also occurs when turbulence is influenced by geometrical means, e.g. by influencing the pressure distribution by the shape of the body (airfoils) or by the introduction of streamwise perturbances on a body (riblets). In the recent years turbulence research has seen increasing attention being focused on the investigation of coherent structures, mainly in Newtonian fluids. We all know that these structures are a significant feature of turbulent flows, playing an important role in the energy balance in such flows. However their place in turbulence theories as weil as the factors influencing their development are still poorly understood. Consequently, the investigation of phenomena in which the properties of coherent structures are alte red provides a promising means of improving our understanding of turbulent flows in general.
Download or read book The Effect of Polymer Structure on Drag Reduction in Nonpolar Solvents written by Gin Chain Liaw and published by . This book was released on 1968 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The effects of polymer chain flexibility, molecular weight and entanglement capacity, and of polymer solution concentration on drag reduction in nonpolar solvents were studied in this investigation. Three samples of polydimethyl siloxane in toluene, five samples of polyethylene oxide in benzene, two samples of cis-polyisoprene in toluene, trans-polyisoprene in toluene, cis-polybutadiene in toluene, ethyl cellulose in toluene and a copolymer of epichlorohydrin and polyethylene oxide in toluene were studied. Molecular weights of all polymers were estimated from intrinsic viscosity, except for the molecular weight of the copolymer which was given by the manufacturer. Turbulent and laminar flow pressure drop data were obtained in four capillary tubes (0.107, 0.0642, 0.0328 and 0.0104 inch ID) for all the polymer-solvent systems. Turbulent flow pressure drop data for some of the above polymer-solvent systems were also obtained in the pipe flow unit (2.0, 1.0 and 0.51 inch ID). For a given tube, at lower concentrations the normal transition region appeared between laminar and turbulent regions; as the concentration increased, the transition tended to disappear. At constant solution concentration, the transition region tended to disappear as the tube diameter decreased ... Correlations were obtained for estimating the amount of drag reduction for "dilute" and "concentration" solutions. Both correlations were tested with the polymer-solvent systems studied in this investigation and with data obtained from literature ... The effect of degradation on drag reduction was more noticeable at lower concentrations than at higher concentrations. This suggests that the absolute rate of molecular degradation may have been approximately the same for all concentrations of any polymer whose wall shear stresses (or shear rates) were of the same magnitude at any given flow rate. In the dilute solutions a significant number of the effective molecules were degraded while in the more concentrated solutions, the same amount of degradation had a much smaller effect on the drag reducing capacity of the solutions"--Abstract, leaves i-iii.
Download or read book Investigating the Degradation Resistance Improvement of the Polymeric Drag Reduction written by Esmail Abdullah Mohammed Basheer and published by . This book was released on 2013 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important practical aspect in the application and study of drag reduction by polymer additives is the degradation of the polymer, for instance due to intense shearing, especially in circulatory flow systems. Such degradation leads to a marked loss of the drag-reducing capability of the polymer. Polymers-Surfactant complex efficacy in reducing the drag and improving the degradation resistance is a new subject in drag reduction research. Turbulent drag reduction (DR) efficacy of ionic Sodium Polystyrene Sulfonate (NaPSS) and sodium Alkylbenzene sulfonate, complexes systems regarding polymer-surfactant interaction was examined under a turbulent flow in a rotating disk apparatus, in which the DR efficacy indicates how the torque is being reduced with a tiny amount of additives under a turbulent flow at a fixed rotational speed. It was found that the addition of the surfactant to the ionic increased the polymer chain dimensions via a conformational structural change, thus enhancing the DR efficacy. Polymer-surfactant system also shows that there exists a critical polymer concentration at which the drag reduction becomes a maximum, and then above the critical concentration, the DR efficacy decreases more rapidly than that of pure polymeric systems. On the other hand, it was found that the addition of the surfactant to the ionic polymer enhance its ability to resist the degradation caused by the high shear stress in the eddy flow. The addition of sodium Alkylbenzene sulfonate to the ionic polymer was found to have higher improvement than the addition of DDAB in degradation resistance. The DR and degradation resistance efficacy induced by the polymer-surfactant mixture is found to be obvious higher than of pure polymer. In addition, the maximum of DR efficacy versus polymer concentration occurred at 700 ppm.
Download or read book Effect of Polymer Coiling on Drag Reduction written by and published by . This book was released on 1966 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tube flow data indicate that the drag reduction of high molecular weight polymer solutions decreases in an orderly fashion with inc.eased molecular coiling of the polymer. A correlating equation for this effect is presented. For three polymers at four concentrations the maximum drag reduction was obtained at temperatures less than 105F and at 140F solutions of all three polymers suffered a decrease in drag reduction. A graphical relationship is presented that qualitatively correlates the variation of viscosity and drag reduction caused by a variation in temperature. A decrease in drag reduction occurs if low concentration of high molecular weight polymers are subjected to steady state turbulent tube flow. A slow decrease in viscosity of high molecular weight solutions due to physical adsorption on the solid surfaces in glassware as well as chemical degradation during static storage can be mitigated by adding isopropanol or using deionized water. The average molecular weight of different samples of the same polymer can vary by as much as 50 percent. (Author).
Download or read book Drag Reduction and Shear Degradation of Dilute Polymer Solutions as Measured by a Rotating Disk written by T. T. Huang and published by . This book was released on 1972 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A saturated drag-reduction line for dilute polymer solutions is derived for a rotating disk from new velocity-similarity laws. Drag reduction measured by a rotating disk is found to have three domains--oversaturated, optimal and undersaturated. At a given boundary-layer thickness and wall-shear stress, the drag-reduction increases with increasing concentration in the undersaturated domain, and the drag reduction does not increase with increasing concentration in the oversaturated domain. The boundary between the two domains is the optimal drag reduction, which is determined by the type of polymer and its concentration and a Reynolds number based on shear velocity and disk radius or boundary-layer thickness. (Author).
Download or read book Report of NRL Progress written by Naval Research Laboratory (U.S.) and published by . This book was released on 1970 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
