4 edition of The converging flow of dilute polymer solutions found in the catalog.
Written in English
|Statement||by Chander Balakrishnan|
|The Physical Object|
|Pagination||xii, 207 leaves :|
|Number of Pages||207|
• The effect of polymer concentration on apparent energy transfer rate and energy dissipation rate is different.! • The effect of both Wi (R!) and concentration may be explained from De Gennesʼ elastic theory (Xi et al, APS/DFD, ).! Fluid mixing plays an essential role in microscale flow systems. Here, we propose an active mixing approach which enhances the mixing of viscoelastic fluid flow in a simplified pore T-junction structure. Mixing is actively controlled by modulating the driving pressure with a sinusoidal signal at the two inlets of the T-junction. The mixing effect is numerically Cited by: 3. 11nce Newton'• dtf!nitlon of vlecoltty does not lead to 1 useful. desc%1ptlon of non•Hewtonlan flow, t• othes-model 11qu14t,. the Maaelqdd and the handtl•iydng :\d an dlacuaetd. & detcJ:1b1n.g the, flow behavlou• of. these liquldt £n nuwow capUla~:&ea •n Author: Henk Van Oene. Dynamic dilution exponent in monodisperse entangled polymer solutions. While the proposed approach successfully explains the viscoelastic properties of a large number of semi-dilute solutions of polymers in their own oligomers, important discrepancies are found for semi-dilute entangled polymers in small-molecule theta or good solvents Cited by:
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Journal of Non-Newtonian Fluid Mechanics, 11 () 31 7 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands FLOW OF DILUTE POLYMER SOLUTIONS THROUGH CONVERGING CHANNELS DAVID F.
JAMES and JOHN H. SARINGER Department of Mechanical Engineering, University of Toronto, Toronto, Ontario (Canada) (Received April Cited by: The laminar flow of dilute polymer solutions through porous media - Volume 70 Issue 4 - David F.
James, D. MclarenCited by: This may imply the utility of the Maxwell model in the suddenly converging flow region of dilute polymer solutions.
In the flow region which follows the abrupt convergence, the value of R ranges froml.0 to and the substitution of the values of rq and b in the present study into eqns. (9) and (10) yields Sx by: It is well known that dilute polymer solutions may exhibit strong viscoelastic flow effects when exposed to elongational flow fields with elongation rates that exceed certain “Onset”-conditions.
Such flow fields occur in the converging-diverging flow passages of a porous matrix but also in regularly packed beds of by: This paper is intended as an overview of the current status of research on the dynamics of dilute polymer solutions, aimed primarily at the “nonspecialist” who is interested in understanding the origins of drag reduction, and other macroscopically observable effects produced by very small quantities of a high molecular weight polymer in a Newtonian by: 7.
Chapter 4 Polymer solutions Introduction Solution: any phase containing more than one component.(gas, liquid or solid) Polymer solution is important: • Classical analyses of polymers are conducted on dilute solutions size exclusion chromatography osmometry, viscometry light scattering.
• Application: adhesives and Size: KB. different flow arrangements, first with a Newtonian fluid and then with drag reducing, dilute polymer solutions.
The pressure drop in excess of the Newtonian baseline, after accounting for viscous effects, was used as a measure of elastic effects. With the dilute polymer solutions, elastic effects were observed both in shear, extensional, asAuthor: Shamsur Rahman.
This paper describes the measurements of heat transfer and drag for the flow of dilute polymer solutions around very small cylinders. The thermal experiments were carried out at Reynolds The converging flow of dilute polymer solutions book less t and the results establish the dependence of the heat transfer on fluid velocity, cylinder diameter, solution concentration, and polymer molecular by: University of Massachusetts Amherst [email protected] Amherst Doctoral Dissertations - February Chain scission in turbulent flow of dilute polymer.
In this paper, an experimental technique is developed to estimate the extensional flow resistance of dilute polymer solutions using flow in a lubricated, converging, and microfluidic channel. Polymers in Dilute Solution – In contrast to dilute particles – In contrast to a polymer melt • The focus of Rouse’s paper is on linear polymers, dilutely suspended in a Newtonian background solvent • The model for the restoring-force law comes from considerations of entropic elasticity, which is motivated by the bead-rod model.
Rheology of Dilute Polymer Solutions with Time-Dependent Screening of Hydrodynamic Interaction s V. Lisy 1, J. Tothova 2, B. Brutovsky 2 The screening of hydrodynamic interactions (HI) essentially affects macroscopic properties of polymeric solutions.
This screening depends not only on the polymer concentration, but has a dynamic : V. Lisy, J. Tothova, B. Brutovsky. Semidilute Polymer Solutions. Since, the overlap of the coils occurs already at a very low polymer concentration.
Therefore, there is a wide concentration region where (i) coils are overlapping and strongly entangled; and (ii). Such solutions are called semidilute. φ* 1 φ 1 0 ∼ 1 Φ 3 1 2 * 1 α N Φ ∝ Dilute solution SemidiluteFile Size: 4MB. Power-Law Polymer Solution Flow in a Converging Annular Spinneret: Analytical Approximation and Numerical Computation Article in AIChE Journal 58(1).
Dilute Solution Viscosity. DSV is a key test method for polymer characterization. By measuring the flow time of a polymer solution through a precision capillary, we can measure the viscosity. This relates to molecular weight. Viscosity of semi-dilute polymer solutions M.
Adam and M. Delsanti Laboratoire Léon-Brillouin, CEN Saclay, Gif sur Yvette Cedex, France (Reçu le 25 mairévisé le 24 aofit, accepté le 3 novembre ) Résumé.
Nous présentons des résultats de viscosité obtenus dans des solutions semi-diluées de polymères (c* c 10%).Cited by: THE JOURNAL OF CHEMICAL PHYSICS() Nonequilibrium thermodynamics of dilute polymer solutions in ﬂow Folarin Latinwo, 1Kai-Wen Hsiao, and Charles M.
Schroeder1,2,3,a) 1Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, IllinoisUSA 2Department of Materials Science and Engineering, University of. TURBULENT PIPE FLOW WITH POLYMER ADDITIVES where η s is the solvent (water) viscosity and e ij the rate-of-deformation tensor.
The well-known Reynolds decomposition is used for the velocity vector u i = (u x,u r,u θ), the pressure p and the polymeric stress τ p,ij, in which lower case with a prime denotes a ﬂuctuation and upper case denotes a mean value (alterna. We investigate the concentration dependence of the characteristic relaxation time of dilute polymer solutions in transient uniaxial elongational flow.
A series of monodisperse polystyrene solutions of five different molecular weights ( × 10 6 ⩽ M ⩽ × 10 6 g ∕ mol) with concentrations spanning five orders of magnitude were dissolved in two solvents of differing Cited by: NON-NEWTONIAN PIPE FRICTION STUDIES WITH VARIOUS DILUTE POLYMER WATER SOLUTIONS t~ INTRODUCTION- --This study is an extension of recent work [lJ * which attempted pre-liminary evaluation of the degree to which certain additives would reduce the shear-friction characteristics of high velocity water flow on a solid bound ary.
BCMU) show that these synthetic random coil polymer chains compress in Couette flow at semi-dilute concentrations. All previous models of polymer flow behaviour have assumed that the chains extend. A new model of polymers in flow in semi-dilute solution is presented where the chains compress in accord with the experimental findings.
Polymer Solution Thermodynamics: 1. Dilute Solutions of Ideal Chains The Gaussian Coil Model The universal properties of polymers can typically be well described through relatively simple models, including continuous chain models, lattice models, and scaling approaches.
An appropriate point ofFile Size: KB. A numerical study of Newtonian and shear-thinning fluids in high-speed, laminar flow through a conical channel is presented. Using a variety of cone-angles and Reynolds numbers on the order ofconverging flow is mapped according to several characteristics: the angle at which separation occurs at the cone outlet, the extent to which sink-flow is approximated, and the Cited by: 2.
dilute solutions. Bajaj et al.  have argued that the different behavior shown by dilute polymer solutions is due to the cou-pling between the velocity and the elastic stress that causes the Fig.
Largest (a and b) and smallest (c and d) eigenvalues of the conformation tensor in the ﬂow domain for an Oldroyd-B ﬂuid. THE EFFECT QE DILUTE SOLUTIONS OF DRAG REDUCING POLYMERS ON RADIATED FLOW NOISE 1.
INTRODUCTION The work reported herein is an effort to show from laboratory experi ment the effect of various conoentrations of water soluble polymers on radiated flow noise from moving objects, as compared with radiated flow. perties of dilute polymer solutions in elongational flow have been made, no direct measurements appear to be available in the literature.
So far, only three methods of generating reasonable approximations to "pure" elongational flow ap-peared suitable: (i) Converging Flow: This method is based on the observation that for some. C.C. Hsieh, S.J. Park, and R.G. Larson, Macromolecules"Brownian dynamics modeling of flow-induced birefringence and chain scission in dilute polymer solutions in a planar cross-slot flow." R.G.
Larson, J. Rheol."The rheology of dilute solutions of flexible polymers: Progress and problems.". Viscosity and longest relaxation time of semi-dilute polymer solutions.
Good solvent M. Adam and M. Delsanti Laboratoire Léon Brillouin, CEN-Saclay (*), Gif-sur-Yvette Cedex, France (Reçu le 10 maiaccepté le 27 juin ) Resume. Des mesures de viscosité à gradient de cisaillement nul ~, et de temps de relaxation le plus long TR. The knowledge of dilute solution viscosity serves as an additional tool in characterizing ethylene polymers.
Viscosity data alone is potentially a limited value in predicting the processing behavior of the polymer. However, when used in conjunction with other flow and physical property values, the solution viscosity of ethylene polymers contributes to characterizing the material.
Solutions exist for arbitrarily large values of, it’s just that current numerical techniques are unable to resolve the high stress and stress boundary layers Wapperom and Renardy () used a Lagrangian technique to solve viscoelastic flow past a cylinder and showed that for an ultra-dilute solution, the governing.
We present a comparative experimental study of a turbulent flow developing in clear water and dilute polymer solutions (25 and 50 wppm polyethylene oxide).
The flow is forced by a planar grid that oscillates vertically with stroke S and frequency f in a square container of initially still fluid. Two-component velocity fields are measured in a vertical plane passing Cited by: A dilute polymer solution is predicted to have a high extensional viscosity but a low shear viscosity, a stress hysteresis, and a slow stress relaxation.
The action of the novel rheology is shown in two simple flows. Finally, speculations are made on the possible way dilute polymer solutions can modify by: The viscosity of very dilute polymer solutions can be described with a simple power law, known as the Mark-Houwink relation.
The Mark-Houwink parameters can be determined from a double logaritmic plot of intrinsic viscosity versus molecular weight which yields straight lines. Extrusion distance giving the maximum swell ratio for semi-dilute polymer solutions For a capillary with a L/D ratio of 85, the swelling of polyacrylamide solution was observed to reach a maximum at a given time t ∞ at a given distance (expressed as a multiple Z of capillary diameter D) from the capillary[ 70 ], i.e., the swelling is by: 5.
10 cm that is roughly independent of Reynolds number. We work with dilute solutions of polyacrylamide in water, and study both the effects of the polymer concentration (ranging from 1 to 15 parts per million (ppm) by weight) and the molecular weight (up to 18 a.m.u.).
Although the apparatus can reach Taylor-microscale Reynolds numbers of up to. long chains the semi-dilute regime covers a wide range of concentrations. Polymer chains are statistically described by the Flory exponent ”, relating the number of monomers N to the radius of gyration: Rg» N”.
The equilibrium properties of polymers in the semi-dilute regime regime are given by scaling laws, with exponents related to. A micro-macro simulation algorithm for the calculation of polymeric flow is developed and implemented. The algorithm couples standard finite element techniques to compute velocity and pressure fields with stochastic simulation techniques to compute polymer stress from simulated polymer by: 2.
Recent developments in dilute polymer solution rheology are reviewed, and placed within the context of the general goals of predicting the complex flow of complex fluids. In particular, the interplay between the use of polymer kinetic theory and continuum mechanics to advance the microscopic and the macroscopic description, respectively, of dilute polymer solution rheology.
Characterization of Polymers in Dilute Solutions The aim of this article is to survey briefly some aspects of molecular characterization of polymer molecules and molecular associates -block copolymer micelles.
Properties of polymer molecules Properties of polymer molecules are Author: Zdenek Tuzar.,Encyclopedia of Fluid Mechanics: Rheology and Non-Newtonian Flows (Volume 7), Nicholas P.
Cheremisinoff, buy best price Encyclopedia of Fluid Mechanics: Rheology and Non-Newtonian Flows (Volume 7), Nicholas P. Cheremisinoff. The behavior of polymer chains both in melt and solution is strongly affected by forces that act to disrupt the ideal distribution of conformations accessible to the chains.
As polymers approach a.Turbulent Drag Reduction by Dilute Solution of Polymers In collaboration with T.S. Lo (TL), A. Pomyalov (AP), I. Procaccia (IP), V. Tiberkevich (VT). – Weizmann Inst., Rehovot, Israel Roberto Benzi, Elizabeth de Angelis, Carlo Casciola – Rome Univ., Italy and Emily Ching –.
Differences in behavior between dilute and concentrated polymer solutions in elongational flow D. Acierno, G. Titomanlio, and R. Greco Chemical Engineering Science,Vol Number 8, Page Cited by: