Download or read book Correlation of Drag Reducing Data in Dilute Polymer Solutions written by Jorge Mario Rodriguez and published by . This book was released on 1966 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The purpose of this investigation was to obtain a correlation for drag reducing solutions in circular tubes under turbulent conditions. Data were taken for three polymer-solvent systems: polymethyl methacrylate V-100 (M[subscript v] ~ 110,000) in toluene, polyisobutylene L-200 (M[subscript v] ~ 4,700,000) in toluene, and polyisobutylene L-200 in cyclohexane. The data from the two polyisobutylene systems, together with other data on polymethyl methacrylate G (M[subscript v] ~ 1,500,000) in toluene and polyisobutylene L-80 (M[subscript v] ~ 860,000) in cyclohexane, were used to attempt to obtain the correlation. The V-100 solutions were not used because they were not drag reducing. The variables that were believed to affect drag, reduction were considered and three dimensionless groups were used as the correlating groups. These groups were: a generalized Reynolds Number (N[subscript Re]' ), a Deborah Number, which is the ratio of the relaxation time of the polymer molecules to a characteristic flow time of the system, and a friction factor ratio. Two different characteristic flow times were used: D/V and n/T[subscript w],which gave rise to two Deborah Numbers. Also, three friction factor ratios were considered. The data were studied by plotting two of the groups and using the third one as a parameter. Several concentrations of each polymer-solvent system were studied individually and the relationships obtained were compared to attempt to obtain a correlation independent of concentration....Several methods for predicting friction factors with some accuracy were developed, but these methods only applied to a given concentration of a system. A relationship between a modified shear stress and velocity that applied to all concentrations of a polymer-solvent system was also obtained, but this method- does not allow accurate predictions of pressure drops"--Abstract, pages vii-viii.
Download or read book Correlation of Turbulent Drag Reduction in Dilute Polymer Solutions with Rheological Properties by an Energy Dissipation Model written by Hsun-fu David Chang and published by . This book was released on 1982 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlations of Turbulent Drag Reduction in Dilute Polymer Solutions written by Ashok K. Jain and published by . This book was released on 1971 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Drag Reduction Degradation of Dilute Polymer Solutions in Turbulent Tube Flow written by Nicholas D. Sylvester and published by . This book was released on 1971 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drag reduction degradation characteristics of Separan AP30 are reported. A recycle tube flow experiment was used to investigate this property of drag reducing polymer solutions. Experimental pressure gradient and flow rate measurements were made as a function of time. From this data, friction factor- time plots on log-log coordinates were constructed, all of which exhibited three distinct regions which are discussed. Correlations are presented relating the process time in which maximum drag reduction exists, and the process time in which significant drag reduction exists, to the polymeric and system flow variables.
Download or read book Drag Reduction in Flow of Dilute Polymer Solutions written by James Henry Hand and published by . This book was released on 1971 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Induced Drag Reduction Based on Stress Relaxation written by Susan Mary Lemke Penix and published by . This book was released on 1987 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduction of Drag in Turbulence by Dilute Polymer Solutions written by Hyunkook Shin and published by . This book was released on 1965 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: The object of this thesis was to investigate the drag reduction phenomenon in turbulent flow caused by random coiling macromolecules in 'dilute' solution. In particular, this thesis was concerned with the relationship of drag (or its reduction) to the size of the coils and their concentration, of two kinds of polymers differing significantly in chain flexibility: polyethylene oxide (PEO), the more flexible, and polyisobutylene (PIB), the less flexible. It was found that, within any given homologous polymer series, the ability of macromolecules to reduce drag improved drastically with increasing molecular weight. That is, the concentration of polymers in solution either in the absolute weight fraction or in the effective volume fraction required to yield a given percent drag reduction decreased rapidly with increasing molecular weight. It was further found that there always existed an optimum concentration for any given polymer system at which the observed drag reduction reached a maximum.
Download or read book Viscous Drag Reduction written by C. Sinclair Wells and published by Springer. This book was released on 2013-12-20 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drag Reduction by Dilute Polymer Solutions in Turbulent Flow written by Ralph C. Little and published by . This book was released on 1967 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanism by which water-soluble polymers reduce hydrodynamic drag on solid surfaces was investigated by measurements of flow birefringence and of turbulent flow in pipes. Flow birefringence and flow field orientation of Polyox polymers in the molecular weight range from 200,000 to 6,000,000 showed that Polyox macromolecules continue to deform with increasing velocity gradient even after alignment with the flow field (at gradients in excess of 2000/sec). All solutions used were found to be Newtonian, with the exception of the AcrysolA-5 solutions. The flow data for Polyox solutions in a Pyrex pipe were examined in terms of Meyer's fluid property parameter and Elata's relaxation time hypothesis for the initiation of drag reduction. It was found that drag reduction in the Pyrex pipe was initiated at a value of the order of one-fifth that predicted by Elata's theory. Moreover, added salt (the solution being 0.3 molar in K2SO4) had no effect on the flow of Polyox Coagulant solutions even though the intrinsic viscosity (upon which Rouse relaxation times depend) was cut to slightly more than one-third of its value in the pure solvent. The unusually high values of Meyer's fluid property parameter observed at low concentrations suggests that adsorption on the Pyrex pipe walls may be playing a role in drag reduction. (Author).
Download or read book Heat Transfer to Drag reducing Polymer Solutions written by Hai Hoang Nguyen and published by . This book was released on 1974 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drag Reduction written by American Institute of Chemical Engineers and published by . This book was released on 1971 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drag Reduction on a Rotating Disk Using a Polymer Additive written by C. Gorman Gilbert and published by . This book was released on 1969 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Drag Reduction written by Robert H. J. Sellin and published by . This book was released on 1984 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Drag Reduction in Dilute Polymer Solutions written by P. E. Roper and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
