Author: P. Moldenaers
Publisher: Elsevier
ISBN: 1483294161
Category : Technology & Engineering
Languages : en
Pages : 1110
Book Description
More than 900 authors from over 35 countries contributed to the 1992 International Congress on Rheology. These proceedings volumes comprise 17 plenary and keynote papers, 250 oral contributions and some 200 poster presentations. All relevant aspects of rheology are covered, e.g., theoretical rheology, molecular theories, fluid mechanics, rheometry, experimental methods, foams, polymer solutions, polymer melts, rubber, solids, composites, biorheology, industrial rheology, polymer processing, food rheology and electrorheology, reflecting the development of rheology into a broad, multidisciplinary field of recognized academic and industrial relevance.
Theoretical and Applied Rheology
Author: P. Moldenaers
Publisher: Elsevier
ISBN: 1483294161
Category : Technology & Engineering
Languages : en
Pages : 1110
Book Description
More than 900 authors from over 35 countries contributed to the 1992 International Congress on Rheology. These proceedings volumes comprise 17 plenary and keynote papers, 250 oral contributions and some 200 poster presentations. All relevant aspects of rheology are covered, e.g., theoretical rheology, molecular theories, fluid mechanics, rheometry, experimental methods, foams, polymer solutions, polymer melts, rubber, solids, composites, biorheology, industrial rheology, polymer processing, food rheology and electrorheology, reflecting the development of rheology into a broad, multidisciplinary field of recognized academic and industrial relevance.
Publisher: Elsevier
ISBN: 1483294161
Category : Technology & Engineering
Languages : en
Pages : 1110
Book Description
More than 900 authors from over 35 countries contributed to the 1992 International Congress on Rheology. These proceedings volumes comprise 17 plenary and keynote papers, 250 oral contributions and some 200 poster presentations. All relevant aspects of rheology are covered, e.g., theoretical rheology, molecular theories, fluid mechanics, rheometry, experimental methods, foams, polymer solutions, polymer melts, rubber, solids, composites, biorheology, industrial rheology, polymer processing, food rheology and electrorheology, reflecting the development of rheology into a broad, multidisciplinary field of recognized academic and industrial relevance.
Brownian Dynamics Simulations of Dilute Polymer Solutions with Complex Hydrodynamics
Journal of Rheology
Author:
Publisher:
ISBN:
Category : Rheology
Languages : en
Pages : 650
Book Description
Includes abstracts from the Journal of the Society of Rheology, Japan.
Publisher:
ISBN:
Category : Rheology
Languages : en
Pages : 650
Book Description
Includes abstracts from the Journal of the Society of Rheology, Japan.
Dynamics Of Complex Fluids: Proceedings Of The Second Royal Society-unilever Indo-uk Forum In Materials Science And Engineering
Author: M J Adams
Publisher: World Scientific
ISBN: 1783263539
Category :
Languages : en
Pages : 513
Book Description
This volume records the presentations and discussions at the Second Royal Society-Unilever Indo-UK Forum on 'Dynamics of Complex Fluids' which was the culmination of the six-month programme on this topic organised at the Issac Newton Institute for Mathematical Sciences, Cambridge University.The authors of this important volume present an up-to-date, wide-ranging view on developments in the analysis of complex fluid behaviour. Emphasis is placed upon the relation between small-scale structure and large-scale response: this brings together the approaches of molecular physics and continuum mechanics.Experiments, constitutive models and computer simulations are combined to yield new insights into the flow behaviour of polymer melts and solutions, colloidal and neutral particle suspensions, and pastes and soils.
Publisher: World Scientific
ISBN: 1783263539
Category :
Languages : en
Pages : 513
Book Description
This volume records the presentations and discussions at the Second Royal Society-Unilever Indo-UK Forum on 'Dynamics of Complex Fluids' which was the culmination of the six-month programme on this topic organised at the Issac Newton Institute for Mathematical Sciences, Cambridge University.The authors of this important volume present an up-to-date, wide-ranging view on developments in the analysis of complex fluid behaviour. Emphasis is placed upon the relation between small-scale structure and large-scale response: this brings together the approaches of molecular physics and continuum mechanics.Experiments, constitutive models and computer simulations are combined to yield new insights into the flow behaviour of polymer melts and solutions, colloidal and neutral particle suspensions, and pastes and soils.
Polymer Dynamics in Dilute Media
Author: Shikha Somani
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 135
Book Description
Polymers undergo a sharp coil to stretch conformational transition in extension dominated flows when the strain rate exceeds a critical value. Dramatic change in flow behavior is known to occur at the coil-stretch transition, making it useful for several commercial applications. Despite decades of study, this phenomenon remains surrounded with controversy as the effect of solvent properties and fluid flow elements on this transition is not fully understood. In this work, we present a study of the coil-stretch transition and related hysteresis phenomenon using stochastic computer simulations. We first investigate the effect of solvent quality on the coil-stretch transition using Brownian dynamics simulations. Unlike experiments, which are plagued with problems related to polydispersity of polymers and inaccurate control over flow profiles, simulations offer a powerful platform to systematically study the effect of solvent quality while keeping all other parameters in the system constant. The system consists of a polymer subjected to planar elongational flow in both theta solvents and good solvents. The polymer is represented by a bead-spring chain model undergoing elongational flow. Solvent-mediated effects such as fluctuating hydrodynamic interactions (HI) and excluded volume (EV) are included rigorously. Conformational hysteresis is understood in terms of a 1-D energy landscape theory with an activation energy barrier for transition. At steady state, depending upon the flow rate, the energy landscape can either have one or two energy wells. An energy landscape with one well corresponds to the coiled state at low flow rate and stretched state at high flowrate. The double welled landscape corresponds to the hysteretic regime where both coiled and stretched conformational states coexist across the ensemble population. A key factor in determining the effect of solvent quality is the use of a proper measure of solvent quality. In almost all earlier studies, the effect of molecular weight on solvent quality has been neglected, producing inconsistent results. Here, the solvent quality is quantified carefully such that the effect of molecular weight and temperature is taken into account. Contrary to earlier findings, it is observed that with improvement in solvent quality, the chains unravel faster and the critical strain rate at which the coil to stretch transition takes place decreases. Furthermore, the solvent quality has a profound effect on the scaling of the critical strain rate with molecular weight and on both the transient and steady state properties of the system. Universal functions are shown to exist for the observed dynamic and static properties, which will prove useful in determining the operating parameters for experiments. In particular, the ratio of the two different relaxation times (longest relaxation time and zero shear rate viscosity) is found to be a universal function of solvent quality independent of molecular weight. The relaxation times (both the longest relaxation time and the zero shear rate viscosity) increase while the critical strain rate is found to decrease with solvent quality. Next, the study of conformational hysteresis is extended to more complicated 3-D flows to understand the effect of flow vorticity on this phenomenon. Heretofore, there has been no systematic methodology for studying the dynamical interactions between polymer molecules and elementary flow patterns in three-dimensional flows. Such a framework is essential not just for gaining valuable insights into the physics of complex fluids at a fundamental level, but it is also crucial for various important applications like turbulent drag reduction where the underlying physical mechanisms involve dynamical interactions between polymers and turbulence fine scale flow features. Such a study is presented here to provide a framework to interpret complex fluid phenomenon in terms of elementary flow patterns. We investigate the conformational hysteresis using rigorous Brownian dynamics simulations and specifically explore the effect of flow vorticity on the lifetime and width of the hysteresis window in 3-D flows. A systematic procedure is developed with careful eigenvalue analysis to explore the sole effect of vorticity on polymer dynamics keeping the principal strain rate fixed. It is observed that the hysteresis width shrinks due to increase in flow vorticity irrespective of the flow type (bi-extensional, bi-compressional, spiral-inwards, spiral-outwards etc). This is further traced to the alignment of eigenvectors with the principal eigenvector direction leading to enhanced fluctuations. Vorticity is found to have a significant effect on both the transient and the steady state properties. Understanding the effect of vorticity on polymer conformational hysteresis can further help in understanding the fundamental processes in complex flows.
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 135
Book Description
Polymers undergo a sharp coil to stretch conformational transition in extension dominated flows when the strain rate exceeds a critical value. Dramatic change in flow behavior is known to occur at the coil-stretch transition, making it useful for several commercial applications. Despite decades of study, this phenomenon remains surrounded with controversy as the effect of solvent properties and fluid flow elements on this transition is not fully understood. In this work, we present a study of the coil-stretch transition and related hysteresis phenomenon using stochastic computer simulations. We first investigate the effect of solvent quality on the coil-stretch transition using Brownian dynamics simulations. Unlike experiments, which are plagued with problems related to polydispersity of polymers and inaccurate control over flow profiles, simulations offer a powerful platform to systematically study the effect of solvent quality while keeping all other parameters in the system constant. The system consists of a polymer subjected to planar elongational flow in both theta solvents and good solvents. The polymer is represented by a bead-spring chain model undergoing elongational flow. Solvent-mediated effects such as fluctuating hydrodynamic interactions (HI) and excluded volume (EV) are included rigorously. Conformational hysteresis is understood in terms of a 1-D energy landscape theory with an activation energy barrier for transition. At steady state, depending upon the flow rate, the energy landscape can either have one or two energy wells. An energy landscape with one well corresponds to the coiled state at low flow rate and stretched state at high flowrate. The double welled landscape corresponds to the hysteretic regime where both coiled and stretched conformational states coexist across the ensemble population. A key factor in determining the effect of solvent quality is the use of a proper measure of solvent quality. In almost all earlier studies, the effect of molecular weight on solvent quality has been neglected, producing inconsistent results. Here, the solvent quality is quantified carefully such that the effect of molecular weight and temperature is taken into account. Contrary to earlier findings, it is observed that with improvement in solvent quality, the chains unravel faster and the critical strain rate at which the coil to stretch transition takes place decreases. Furthermore, the solvent quality has a profound effect on the scaling of the critical strain rate with molecular weight and on both the transient and steady state properties of the system. Universal functions are shown to exist for the observed dynamic and static properties, which will prove useful in determining the operating parameters for experiments. In particular, the ratio of the two different relaxation times (longest relaxation time and zero shear rate viscosity) is found to be a universal function of solvent quality independent of molecular weight. The relaxation times (both the longest relaxation time and the zero shear rate viscosity) increase while the critical strain rate is found to decrease with solvent quality. Next, the study of conformational hysteresis is extended to more complicated 3-D flows to understand the effect of flow vorticity on this phenomenon. Heretofore, there has been no systematic methodology for studying the dynamical interactions between polymer molecules and elementary flow patterns in three-dimensional flows. Such a framework is essential not just for gaining valuable insights into the physics of complex fluids at a fundamental level, but it is also crucial for various important applications like turbulent drag reduction where the underlying physical mechanisms involve dynamical interactions between polymers and turbulence fine scale flow features. Such a study is presented here to provide a framework to interpret complex fluid phenomenon in terms of elementary flow patterns. We investigate the conformational hysteresis using rigorous Brownian dynamics simulations and specifically explore the effect of flow vorticity on the lifetime and width of the hysteresis window in 3-D flows. A systematic procedure is developed with careful eigenvalue analysis to explore the sole effect of vorticity on polymer dynamics keeping the principal strain rate fixed. It is observed that the hysteresis width shrinks due to increase in flow vorticity irrespective of the flow type (bi-extensional, bi-compressional, spiral-inwards, spiral-outwards etc). This is further traced to the alignment of eigenvectors with the principal eigenvector direction leading to enhanced fluctuations. Vorticity is found to have a significant effect on both the transient and the steady state properties. Understanding the effect of vorticity on polymer conformational hysteresis can further help in understanding the fundamental processes in complex flows.
Papers Presented at the ... Meeting
Author: American Chemical Society. Division of Polymer Chemistry
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 756
Book Description
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 756
Book Description
Progress and Trends in Rheology II
Author: H. Giesekus
Publisher: Springer Science & Business Media
ISBN: 3642493378
Category : Science
Languages : en
Pages : 513
Book Description
Following an invitation from the Czechoslovakian The scientific programme consisted of 14 plenary delegates at the First Conference of European Rheo lectures as weIl as 310 short presentations, which were logists at Graz in 1982 and adecision by the European held in six parallel sessions in seven half-day sittings. members of the International Committee of Rheology The provision of a reading room containing submitted at the 1983 "Conference of Engineering Rheology" in manuscripts of talks presented at the meeting proved London, the Rheology Group of the Czechoslovak to be popular and seems a worthwhile addition to any Chemical Society (Chairman: Doz. lug. l. Sestak meeting, at least those holding parallel sessions. There CSc.) was entrusted with the organization of the Sec was also a display by nine companies of a wide variety ond Conference of European Rheologists. For an of current rheological instruments. outline of the process leading to the decision to hold The programme for accompanying persons befitted such European meetings, see the Introduction to the the historical significance of the region. The evening Proceedings of the First Conference of European programme included an opening ceremony and recep Rheologists; Rheol Acta 21:355-356 (1982). tion on Monday and an informal banquet on Thurs This Conference was held in the Prague Palace of day as weIl as a visit to the opera.
Publisher: Springer Science & Business Media
ISBN: 3642493378
Category : Science
Languages : en
Pages : 513
Book Description
Following an invitation from the Czechoslovakian The scientific programme consisted of 14 plenary delegates at the First Conference of European Rheo lectures as weIl as 310 short presentations, which were logists at Graz in 1982 and adecision by the European held in six parallel sessions in seven half-day sittings. members of the International Committee of Rheology The provision of a reading room containing submitted at the 1983 "Conference of Engineering Rheology" in manuscripts of talks presented at the meeting proved London, the Rheology Group of the Czechoslovak to be popular and seems a worthwhile addition to any Chemical Society (Chairman: Doz. lug. l. Sestak meeting, at least those holding parallel sessions. There CSc.) was entrusted with the organization of the Sec was also a display by nine companies of a wide variety ond Conference of European Rheologists. For an of current rheological instruments. outline of the process leading to the decision to hold The programme for accompanying persons befitted such European meetings, see the Introduction to the the historical significance of the region. The evening Proceedings of the First Conference of European programme included an opening ceremony and recep Rheologists; Rheol Acta 21:355-356 (1982). tion on Monday and an informal banquet on Thurs This Conference was held in the Prague Palace of day as weIl as a visit to the opera.
Oscillatory Flow Birefringence of Dilute Polymer Solutions
Author: Timothy Lodge
Publisher:
ISBN:
Category : Polymerization
Languages : en
Pages : 482
Book Description
Publisher:
ISBN:
Category : Polymerization
Languages : en
Pages : 482
Book Description
Rheology
Author: Giovanni Astarita
Publisher: Springer Science & Business Media
ISBN: 1468437437
Category : Science
Languages : en
Pages : 646
Book Description
At the VIIth International Congress on Rheology, which was held in Goteborg in 1976, Proceedings were for the first time printed in advance and distributed to all participants at the time of the Congress. Although of course we Italians would be foolish to even try to emulate our Swedish friends as far as efficiency of organization is concerned, we decided at the very beginning that, as far as the Proceedings were concerned, the VIIIth International Congress on Rheology in Naples would follow the standards of time liness set by the Swedish Society of Rheology. This book is the result we have obtained. We wish to acknowledge the cooperation of Plenum Press in producing it within the very tight time schedule available. Every four years, the International Congress on Rheology represents the focal point where all rheologists meet, and the state of the art is brought up to date for everybody interested; the Proceedings represent the written record of these milestones of scientific progress in rheology. We have tried to make use of the traditions of having invited lectures, and of leaving to the organizing committee the freedom to choose the lecturers as they see fit, in order to collect a group of invited lectures which gives as broad as possible a landscape of the state of the art in every relevant area of rheology. The seventeen invited lectures are collected in the first volume of the proceedings.
Publisher: Springer Science & Business Media
ISBN: 1468437437
Category : Science
Languages : en
Pages : 646
Book Description
At the VIIth International Congress on Rheology, which was held in Goteborg in 1976, Proceedings were for the first time printed in advance and distributed to all participants at the time of the Congress. Although of course we Italians would be foolish to even try to emulate our Swedish friends as far as efficiency of organization is concerned, we decided at the very beginning that, as far as the Proceedings were concerned, the VIIIth International Congress on Rheology in Naples would follow the standards of time liness set by the Swedish Society of Rheology. This book is the result we have obtained. We wish to acknowledge the cooperation of Plenum Press in producing it within the very tight time schedule available. Every four years, the International Congress on Rheology represents the focal point where all rheologists meet, and the state of the art is brought up to date for everybody interested; the Proceedings represent the written record of these milestones of scientific progress in rheology. We have tried to make use of the traditions of having invited lectures, and of leaving to the organizing committee the freedom to choose the lecturers as they see fit, in order to collect a group of invited lectures which gives as broad as possible a landscape of the state of the art in every relevant area of rheology. The seventeen invited lectures are collected in the first volume of the proceedings.
Stochastic Processes in Polymeric Fluids
Author: Hans C. Öttinger
Publisher: Springer Science & Business Media
ISBN: 3642582907
Category : Technology & Engineering
Languages : en
Pages : 384
Book Description
This book consists of two strongly interweaved parts: the mathematical theory of stochastic processes and its applications to molecular theories of polymeric fluids. The comprehensive mathematical background provided in the first section will be equally useful in many other branches of engineering and the natural sciences. The second part provides readers with a more direct understanding of polymer dynamics, allowing them to identify exactly solvable models more easily, and to develop efficient computer simulation algorithms in a straightforward manner. In view of the examples and applications to problems taken from the front line of science, this volume may be used both as a basic textbook or as a reference book. Program examples written in FORTRAN are available via ftp from ftp.springer.de/pub/chemistry/polysim/.
Publisher: Springer Science & Business Media
ISBN: 3642582907
Category : Technology & Engineering
Languages : en
Pages : 384
Book Description
This book consists of two strongly interweaved parts: the mathematical theory of stochastic processes and its applications to molecular theories of polymeric fluids. The comprehensive mathematical background provided in the first section will be equally useful in many other branches of engineering and the natural sciences. The second part provides readers with a more direct understanding of polymer dynamics, allowing them to identify exactly solvable models more easily, and to develop efficient computer simulation algorithms in a straightforward manner. In view of the examples and applications to problems taken from the front line of science, this volume may be used both as a basic textbook or as a reference book. Program examples written in FORTRAN are available via ftp from ftp.springer.de/pub/chemistry/polysim/.