The Influence of Polymer Additives on Velocity and Temperature Fields: Symposium Universität -- Gh -- Essen, Germany, June 26-28, 1984

ISBN-13: 9783642826344 / Angielski / Miękka / 2011 / 446 str.

Bernhard Gampert

Opis

The Symposium on "The Influence of Polymer Additives on Veloc- ity and Temperature Fields" was proposed to the General Assem- bly of the International Union of Theoretical and Applied Me- chanics (IUTAM) by the "Gesellschaft fur Angewandte Mathematik und Mechanik" (GAMM). The Symposium was held under the auspices of IUTAM in association with the "Deutsche Rheologische Ge- sellschaft" (DRG) with responsibility for the organization ly- ing with B. Gampert (Universitat-GH-Essen). The main aim of this IUTAM Symposium was to consider the funda- mental aspects of the phenomena that occur when small amounts of polymers are added to turbulent flows (turbulent drag re- duction) and laminar porous media flows. In particular atten- tion was devoted to - the influence of molecular parameters of the polymers and solution properties, especially the elongational viscosity, on turbulent flow and laminar porous media flow; the influence of polymers on the turbulence structure in polymer drag reduction.

Spis treści

Session I.- * Turbulent drag reduction by. polymer additives: a survey.- Session 2 Extensional Viscosity.- * A review on extensional viscosity.- Flow-induced conformation change in dilute polymer solution — A comparison between non-ionic polymers and polyelectrolytes.- The nature of flow through porous media.- An experimental study of polymer induced drag for flows through porous medium.- Session 3 Molecular Parameters I.- * Molecular parameters as a basis of structure-property-relations in the flow of polymer solutions.- Drag reduction of non-ionic surfactant mixtures.- The influence of molecular weight and molecular weight distribution on drag reduction and mechanical degradation in turbulent flow of highly dilute polymer solutions.- Session 4 Molecular Parameters II.- Influence of molecular parameters on laminar non-Newtonian and on turbulent flows of dilute polymer solutions.- The peculiarities of the structure of wall turbulence and the mechanism of drag reduction by polymer additives.- # The influence of molecular mass distribution, size and elasticity of macromolecules on friction reduction effect.- Characterization of dilute Polyacrylamide and polystyrene solutions by means of porous media flow.- The effect of grafted and ungrafted guargum on turbulent flow of water and on hydraulic conductivity of soil.- Session 5 Molecular Parameters III.- * Some fringe effects of the flow on the macromolecules in dilute polymer and on their non-Newtonian behaviour.- Aging of aqueous polymer solutions.- Model for effects of degradation on polymer drag reduction.- Elastico-viscous effects in complex flows.- Session 6 Theories I.- Turbulence measurements with viscoelastic flow in an open channel.- A mechanism for polymer drag reduction.- # A turbulence model for drag reduction dilute polymer solutions in boundary layer on a flat plate.- Session 7 Structures in Turbulence I.- * The structure near the wall in turbulent shear flow.- Statistical measurements in the turbulent flow of dilute drag-reducing polymer solutions in a round tube.- The vorticity diffusion of ?-vortices in drag reducing solutions.- Session 8 Structures in Turbulence II.- Influence of polymer additives on neutral stability of Görtler vortices.- ° Laser-Doppler measurements of vortex-shedding past small circular cylinders in dilute polymer solutions.- Influence of polymer additives on turbulence in a mixing layer.- The turbulent mixing of viscoelastic fluids in pipe flow.- Session 9 Theories II.- * A qualitative understanding of drag reduction by polymers.- Predictions of turbulent drag reduction for a linear viscoelastic fluid.- An engineering approach to modeling complex flow behavior of polymer solutions.- Session 10 Injection Experiments.- Heterogeneous drag reduction in turbulent pipe flow.- Annular injection of concentrated polymer solutions into the wall region of a turbulent pipe flow.- Turbulence structure of a developing duct flow with near-wall injection of drag reducing polymers.- Session II.- * Today and future possibilities of industrial applications of drag reduction.- Session 12 Pressure Fields, Cavitation.- Effects of a non-Newtonian fluid on the velocity distribution and pumping efficiency of peristaltic pumping.- Effect of polymer solutions on tip vortex cavitation.- The influence of non-Newtonian liquids on the cavitation thresholds and on the pressure pulse velocity in two-phase mixtures.- Session 13 Heat and Mass Transfer.- Nucleate boiling in drag-reducing polymer solutions.- Mass transfer in elongational flows of dilute polymer solutions.