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 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 Flat Plate Frictional Drag Reduction with Polymer Injection written by Justin H. McCarthy and published by . This book was released on 1970 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is developed for prediction of frictional drag reduction in high Reynolds number flows past smooth flat plates with polymer injection near the leading edge. Numerical results are given for water-Polyox WSR 301 solutions with either uniform concentration or injection. (Author).
Download or read book Lift and Drag Effects Due to Polymer Injections on the Surface of Symmetric Hydrofoils written by Abbas M. Sinnarwalla and published by . This book was released on 1976 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental results are presented for the effects on the lift and drag on symmetrical hydrofoils due to the injection of dilute polymer solutions on to their surfaces. Results are presented for three different polymers, namely, Polyox, Polyacrylamide and Jaguar; for purposes of comparison, results are also presented for water injection. The results indicate that while, in general, polymer injection leads to a reduction in drag, the lift can either increase or decrease depending on the polymer, the angle of attack, the surface on which the injection is made, the chordwise location at which injection is made and the injection velocity. Results for the effects of the injections on the pressure distributions on the hydrofoil are also presented, and these results are consistent with the force measurements. Tests on the effects of simultaneous injections from several chordwise locations indicate that significant reductions in drag can be achieved by a judicious choice of the locations.
Download or read book Drag Reducing Polymer Molecular Weight Effects on Turbulent Diffusion for Uniformly Distributed Polymer Injection written by R. R. Walters and published by . This book was released on 1974 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of polymer molecular weight on turbulent diffusion and drag-reduction was investigated over a uniformly distributed polymer injection area. The purpose of the experiments, carried out in a porous wall pipe flow facility, was to determine optimum values of polymer molecular weight and injection mass flux for attaining maximum skin-friction reduction over a distributed injection area and to investigate associated turbulent diffusion characteristics. It was found for this type of polymer supply system, which provided polymer directly to the required wall shear stress region, that the optimum molecular weight was approximately an order of magnitude less than that normally used in skin-friction reduction applications with homogeneous solutions and localized injection ...Abstract, p. iii.
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 Boundary Layer Drag Reduction by Injection of Polymer Solutions written by Richard Le Tessier and published by . This book was released on 1989 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Viscous Drag Reduction in Boundary Layers written by and published by AIAA. This book was released on 1990 with total page 542 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 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 Polymer Injection Into a Developing Boundary Layer written by J. Paul Tullis and published by . This book was released on 1976 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the last phase of a study on the drag reduction at the entrance region of a 12-inch pipe by injection of polymer solutions. In this phase of the study the effect of injecting concentrated solutions of WSR 301, up to 3600 ppmw, was examined. This study indicates that the local friction downstream from the injector can be considerably reduced by increasing the discharge of the polymer injected into the pipe. However, the injection disturbs the flow and increases the pressure losses across the injector. When the total drag reduction of a given pipe length (X/D), which includes the losses due to the injection, is considered, it is found that different optimal conditions exist for reducing the drag of short pipe sections and for reducing the drag of long pipe sections. This report also summarizes a study of drag reduction in a pipe flow of Calgon TRO-375 solutions. For certain tests, this polymer caused an apparent increase in the effective roughness of the pipe walls. In addition, the report summarizes a study of the effect of a polymer (WSR 301) on the cavitation characteristics of a pipe orifice. (Author).
Download or read book Investigation of Drag Reduction Obtained Through Boundary Layer Injection of Dilute Solutions of Poly ethylene oxide written by Brian J. Doherty and published by . This book was released on 1965 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this investigation were: To determine whether or not a significant reduction in drag could be obtained by the addition of a dilute high molecular weight linear polymer solution to the boundary layer surrounding a test model; To observe by closely controlling the experiment, how the effect of the polymer varied with vehicle velocity, injection rate and solution concentration; To determine how the additive was able to change the drag. The polymer used in this series of tests was Polyox WSR-301, a water soluble Poly-ethelene oxide produced by Union Carbide Corporation. It was chosen because it appeared to promise best results from pipe flow and rotating disk experiments. The dilute polymer solution was ejected from the model into the boundary layer. By varying the velocity, additive concentration and injection rate it was possible to determine how the drag reduction varied with these parameters.
Download or read book Drag Reduction by Centrally Injected Polymer Jet written by Pankaj Kumar Sinha and published by . This book was released on 1984 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Drag Reducing Polymer Injection on the Lift and Drag of a Two Dimensional Hydrofoil written by D. H. Fruman and published by . This book was released on 1974 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present paper describes an experimental investigation on the effects of injecting drag-reducing polymer solutions into the turbulent boundary layer of two NACA 63, two-dimensional, symmetrical, hydrofoils. The experiments were performed in a high-speed circulating channel with free stream velocities of up to 13 m/sec. The two foils used were 10 and 20 cm in chord, though both had a maximum thickness of 2 cm. The incidence of the foils varied between plus or minus 5 degrees with the ratios of the injection to free stream velocity of up to 0.2, and a concentration of poly(ethylene oxide), POLYOX WSR 301, of 200 ppm. The injection slits on both foils are situated one-tenth of a chord downstream of the leading edge. The gap of the injection slit was 0.0127 cm for the small foil and twice this value for the larger foil. (Modified author abstract).
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 Experiments on Polymer Drag Reduction Using PIV and PLIF written by and published by . This book was released on 2001 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure of turbulence in a drag reduced flat plate boundary layer has been studied with particle image velocimetry (PlV) and planar laser induced fluorescence (PLIF). Drag reduction was achieved by injection of a solution of water-soluble polymer through a spanwise slot near the leading edge of the flat plate. Velocity and concentration data were obtained using PrV and PLIF, respectively, in planes parallel to the wall (x-z plane) and perpendicular to the wall (x-y plane). Measurements of velocity, vorticity and streak spacing were obtained and trends analyzed. For increasing drag reduction, damping of streak oscillations, suppression of streak splitting and merging, streak stabilization and coarsening of the low speed streaks was observed. PLIF measurements of the injected polymer solution showed that regions of high polymer concentration are correlated with the low speed streaks. PW measurements in the x-y plane showed that at Maximum Drag Reduction (MDR) there are sighificant differences in the statistics of turbulence between boundary layers with polymer injection and channel flow with an ocean of polymer suggesting that in this sense, the achievement of MDR in flows with polymer addition is not unique.
Download or read book Design of Slurry Transport Systems written by B.E.A. Jacobs and published by CRC Press. This book was released on 2003-09-02 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book benefits users, manufacturers and engineers by drawing together an overall view of the technology. It attempts to give the reader an appreciation of the extent to which slurry transport is presently employed, the theoretical basis for pipeline design, the practicalities of design and new developments.
