Download or read book Numerical and Experimental Studies of the Motion of Solid Particles in Viscoelastic Fluids written by James Jingtao Feng and published by . This book was released on 1995 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Simulation of the Motion of Solid Particles in Viscoelastic Fluids written by Peter Yijian Huang and published by . This book was released on 1997 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particles Bubbles Drops written by Efstathios Michaelides and published by World Scientific. This book was released on 2006 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of multiphase flows has grown by leaps and bounds in the last thirty years and is now regarded as a major discipline. Engineering applications, products and processes with particles, bubbles and drops have consistently grown in number and importance. An increasing number of conferences, scientific fora and archived journals are dedicated to the dissemination of information on flow, heat and mass transfer of fluids with particles, bubbles and drops. Numerical computations and "thought experiments" have supplemented most physical experiments and a great deal of the product design and testing processes. The literature on computational fluid dynamics with particles, bubbles and drops has grown at an exponential rate, giving rise to new results, theories and better understanding of the transport processes with particles, bubbles and drops. This book captures and summarizes all these advances in a unified, succinct and pedagogical way. Contents: Fundamental Equations and Characteristics of Particles, Bubbles and Drops; Low Reynolds Number Flows; High Reynolds Number Flows; Non-Spherical Particles, Bubbles and Drops; Effects of Rotation, Shear and Boundaries; Effects of Turbulence; Electro-Kinetic, Thermo-Kinetic and Porosity Effects; Effects of Higher Concentration and Collisions; Molecular and Statistical Modeling; Numerical Methods-CFD. Key Features Summarizes the recent important results in the theory of transport processes of fluids with particles, bubbles and drops Presents the results in a unified and succinct way Contains more than 600 references where an interested reader may find details of the results Makes connections from all theories and results to physical and engineering applications Readership: Researchers, practicing engineers and physicists that deal with any aspects of Multiphase Flows. It will also be of interest to academics and researchers in the general fields of mechanical and chemical engineering.
Download or read book Numerical Methods for the Study of Deformable Bodies in Viscous and Viscoelastic Flows written by Christopher John Guido and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Suspended soft particles in viscoelastic fluids are ubiquitous in biological applications and are being utilized with increasing frequency in microfluidic platforms. Biological fluids are often laden with cells or swimming microorganisms which are highly deformable, while the suspending fluid usually includes polymeric macromolecules that impart elasticity to the fluid. These highly elastic fluids can be found in the human body in mucus linings, in direct-write additive manufacturing applications, and even in injectable therapeutics. In this work we present the development of a high-fidelity simulation tool with general constitutive model implementations for both the viscoelastic fluid and deformable solid to understand the physics behind these complex systems. We discuss a modified version of the IFEM (Immersed Finite Element Method) that allows for the simulation of deformable particles in viscoelastic flows which minimizes the need for costly re-meshing operations and scales well in particle number. This simulation tool is validated for a number of simple Newtonian and viscoelastic cases to ensure the fidelity of the presented algorithm. Lastly, we consider a series of specific applications that demonstrate the breadth and scalability of the simulation platform. Specifically, we consider the slowdown of swimming microorganisms in viscoelastic fluids, the rheology of soft particles in viscoelastic shear flows, and the dynamics of red blood cells in small arteriole flow and AFM indentation. We emphasize the study of swimming behavior of undulatory and amoeboid swimmers in viscoelastic fluids. The undulating swimmer C. elegans is an excellent case study since it is both experimentally well-studied and the microorganism's motion resembles the behavior of many other biological structures, like cilia or flagella. Additionally, there is a well-known speed decrease as the Deborah number increases that has been experimentally observed but, to date, has not been studied numerically with a fully resolved three-dimensional simulation. In this work, we discuss the use of the IFEM with an added conformation-driven force or extra surface traction that allows the swimmer to evolve through an arbitrary set of specified shapes. We compare numerical results for C. elegans against experimental speed data provided by Shen and Arratia (2011) and the speed reduction as a function of Deborah number is presented with good agreement for Oldroyd-B fluids. A similar set of results is considered for the amoeboid swimmer which has never been numerically studied in viscoelastic fluids. The simulation tool is then further utilized to explore the underlying physical mechanism that drives swimming speed reduction in viscoelastic fluids, including comparison to other more simplified simulations/theories. The role of polymer stretch boundary layers near the surface of these swimmers is noteworthy, which demonstrates the need for fully resolved simulations which take into account the finite size of the microorganism. Additionally, we highlight the study of rheology of soft particles in viscoelastic flows. While studies to date have investigated the dynamics of soft solids and membranes in pressure driven flow as well as the shapes and dynamics of soft particles in simple shear flows, little work has been completed to examine the effective rheology of suspensions of these particles. In this work, we discuss the application of the IFEM to the motion of deformable Neo-Hookean solid particles in simple viscoelastic shear flows. We then discuss the interplay of fluid elasticity and particle elasticity and how this effects the key viscometric functions for shear flows. We break the viscometric measurables into contributing parts from the fluid (particle induced fluid stress) and the particle (stresslet) that show interesting trends and underlying physical principles. We find that all components of the particle induced fluid stress are nearly invariant to the deformation (within the parameter range studied), while the shear stress component of the stresslet rapidly decreases in magnitude as elasticity in the fluid increases. These rheological measures have widespread impact for the design of microfluidic devices and we believe that further investigation of these findings will aid in the design of engineered fluids. The simulation tool also has the capability of allowing the simulation of denser suspensions of particles and more complex geometries opening many new possibilities for future studies of soft matter in viscoelastic fluids.
Download or read book Solid Liquid Two Phase Flow written by Sümer M. Peker and published by Elsevier. This book was released on 2011-04-18 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an undertaking of a pioneering work of uniting three vast fields of interfacial phenomena, rheology and fluid mechanics within the framework of solid-liquid two phase flow. No wonder, much finer books will be written in the future as the visionary aims of many nations in combining molecular chemistry, biology, transport and interfacial phenomena for the fundamental understanding of processes and capabilities of new materials will be achieved. Solid-liquid systems where solid particles with a wide range of physical properties, sizes ranging from nano- to macro- scale and concentrations varying from very dilute to highly concentrated, are suspended in liquids of different rheological behavior flowing in various regimes are taken up in this book. Interactions among solid particles in molecular scale are extended to aggregations in the macro scale and related to settling, flow and rheological behavior of the suspensions in a coherent, sequential manner. The classical concept of solid particles is extended to include nanoparticles, colloids, microorganisms and cellular materials. The flow of these systems is investigated under pressure, electrical, magnetic and chemical driving forces in channels ranging from macro-scale pipes to micro channels. Complementary separation and mixing processes are also taken under consideration with micro- and macro-scale counterparts. - Up-to-date including emerging technologies- Coherent, sequential approach- Wide scope: microorganisms, nanoparticles, polymer solutions, minerals, wastewater sludge, etc- All flow conditions, settling and non-settling particles, non-Newtonian flow, etc- Processes accompanying conveying in channels, such as sedimentation, separation, mixing
Download or read book Viscoelasticity and Rheology written by Arthur S. Lodge and published by Academic Press. This book was released on 2014-06-28 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viscoelasticity and Rheology covers the proceedings of a symposium by the same title, conducted by the Mathematics Research Center held at the University of Wisconsin-Madison on October 16-18, 1984. The contributions to the symposium are divided into four broad categories, namely, experimental results, constitutive theories, mathematical analysis, and computation. This 16-chapter work begins with experimental topics, including the motion of bubbles in viscoelastic fluids, wave propagation in viscoelastic solids, flows through contractions, and cold-drawing of polymers. The next chapters covering constitutive theories explore the molecular theories for polymer solutions and melts based on statistical mechanics, the use and limitations of approximate constitutive theories, a comparison of constitutive laws based on various molecular theories, network theories and some of their advantages in relation to experiments, and models for viscoplasticity. These topics are followed by discussions of the existence, regularity, and development of singularities, change of type, interface problems in viscoelasticity, existence for initial value problems and steady flows, and propagation and development of singularities. The remaining chapters deal with the numerical simulation of flow between eccentric cylinders, flow around spheres and bubbles, the hole pressure problem, and a review of computational problems related to various constitutive laws. This book will prove useful to chemical engineers, researchers, and students.
Download or read book Particles Bubbles And Drops Their Motion Heat And Mass Transfer written by Stathis Efstathios E Michaelides and published by World Scientific. This book was released on 2006-04-24 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of multiphase flows has grown by leaps and bounds in the last thirty years and is now regarded as a major discipline. Engineering applications, products and processes with particles, bubbles and drops have consistently grown in number and importance. An increasing number of conferences, scientific fora and archived journals are dedicated to the dissemination of information on flow, heat and mass transfer of fluids with particles, bubbles and drops. Numerical computations and “thought experiments” have supplemented most physical experiments and a great deal of the product design and testing processes. The literature on computational fluid dynamics with particles, bubbles and drops has grown at an exponential rate, giving rise to new results, theories and better understanding of the transport processes with particles, bubbles and drops. This book captures and summarizes all these advances in a unified, succinct and pedagogical way.
Download or read book The Effects of Fluid Elasticity and Flow on the Motion of Settling Particles written by William Levi Murch and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle suspensions are ubiquitous across a variety of engineering processes, and examples can be found in oilfield applications, industrial separations, microfluidics, and additive manufacturing. In these applications, it is crucial to control and predict the mobility of the particles -- that is, their motion through a fluid due to an applied force. Often, that applied force is due to gravity, and the process of interest involves the sedimentation of rigid, non-Brownian particles. In many industrially-relevant processes, the suspending fluid is a polymeric fluid, which can exhibit both viscous and elastic flow behavior. In this work, we examine the effect of fluid elasticity on the motion of settling particles. To do so, we use a combination of experiments and large-scale numerical simulations to build a fundamental understanding of how and why the settling motion of spherical particles changes in elastic fluids. We begin by studying the motion of a single spherical particle in a model elastic Boger fluid. Initially, we address the case where a shear flow is imposed in a plane perpendicular to the sphere's motion, referred to as cross (or orthogonal) shear. We study the settling motion in highly elastic fluids, where the sphere's motion and the shear flow both result in significant stretching of the polymers in solution. We find that the shear flow results in polymer tension along the fluid streamlines and creates regions of high polymer stretching in the wake of the sphere which extend into the shear flow direction. We observe that these viscoelastic wake structures, resembling wings, are linked to an increase in the pressure drag, which drives a dramatic decrease in the particle's settling rate in the presence of a cross shear flow. In a surprising extension to this work, we show that rotation of a spherical particle (around the axis aligned with its motion) in an otherwise quiescent elastic fluid can result in the opposite trend: an increase in the sphere's settling rate as a function of its rotation rate. In this case, we propose a mechanism based on the generation of hoop stresses around the rotating and sedimenting sphere. Returning to the case of a spherical particle settling through a sheared elastic fluid, we find that the coupling between the particle's motion and an external shear flow depends on the direction of the applied force relative to the shear flow. Interestingly, when the particle settles in either the shear gradient or shear flow direction, a lateral drift becomes apparent. Utilizing the understanding gained from our single particle studies, we subsequently address the settling motion of a suspension of rigid particles at finite volume fraction. When the fluid is quiescent, we observe a characteristically distinct settling behavior in a viscoelastic suspending fluid compared to a Newtonian fluid: in the viscoelastic fluid, we observe the formation of particle-rich regions which settle more quickly, resulting in an inhomogeneous settling behavior and an overall enhanced settling rate. We propose that this structural concentration instability is driven in part by the lateral drift of particles in elastic fluids due to local concentration variations following random mixing. Alternatively, when a cross shear flow is applied, a hindered settling rate is observed -- we attribute this result to both the effect of elasticity in a cross sheared viscoelastic fluid (as initially addressed for a single particle) and the mixing of the suspension structure due to the shear flow. These results have significant implications for engineering applications involving suspensions of particles settling in both quiescent and flowing polymeric fluids. In summary, we examine the nonlinear coupling between the settling motion of a particle and a surrounding flow field in elastic fluids through a number of fundamental examples. Using experiments and simulations, we infer the coupling relations (when possible) and propose mechanisms to describe them on a physical basis. We use this knowledge to then study the industrially-relevant problem of a suspension of settling particles, with or without an applied flow. This work provides a framework for better understanding and predicting the settling behavior of rigid particles in polymeric fluids.
Download or read book Theoretical and Experimental Studies of the Mechanics of Viscoelastic Liquids written by D. D. Joseph and published by . This book was released on 1985 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical and experimental studies of a wide range of problems in the rheometry of viscoelastic fluids are described. A device to measure the shear relaxation function has been invented (the wave speed meter). Investigations of the conditions under which the equations for the flow of viscoelastic liquids can change type have been carried out. The results from experiments and analyses on a variety of problems associated with bicomposed flows of liquids with different viscosities are presented. These included liquid rollers, the flow of two liquids in a pipe, and Taylor instability with two immiscible liquids. Analysis and experiments of the motion of a viscoelastic liquid between eccentric rotating cylinders are described. Some analytical results for the extrudate swell problem are presented. The climbing constants for a wide range of viscoelastic liquids have been measured. Other projects include stability analyses for several flow geometries; experiments on viscoelastic liquid breakup; and experiments on the stability of a rotating and coning cylinder. Keywords include: Rheology; Viscoelastic liquids; Wave speed meter; Discontinuities; Hyperbolicity; Change of type; Bicomponent flows; Rotating cylinders; Liquid rollers; Jets; Die swell; Liquid breakup; Climbing constants; Fading memory; Instabilities; Coning cylinder.
Download or read book Rheology and Fluid Mechanics of Nonlinear Materials written by and published by . This book was released on 1996 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers presented at the ASME International Mechanical Engineering Congress and Exposition.
Download or read book Fluid Dynamics of Viscoelastic Liquids written by Daniel D. Joseph and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about two special topics in rheological fluid mechanics: the elasticity of liquids and asymptotic theories of constitutive models. The major emphasis of the book is on the mathematical and physical consequences of the elasticity of liquids; seventeen of twenty chapters are devoted to this. Constitutive models which are instantaneously elastic can lead to some hyperbolicity in the dynamics of flow, waves of vorticity into rest (known as shear waves), to shock waves of vorticity or velocity, to steady flows of transonic type or to short wave instabilities which lead to ill-posed problems. Other kinds of models, with small Newtonian viscosities, give rise to perturbed instantaneous elasticity, associated with smoothing of discontinuities as in gas dynamics. There is no doubt that liquids will respond like elastic solids to impulses which are very rapid compared to the time it takes for the molecular order associated with short range forces in the liquid, to relax. After this, all liquids look viscous with signals propagating by diffusion rather than by waves. For small molecules this time of relaxation is estimated as lQ-13 to 10-10 seconds depending on the fluids. Waves associated with such liquids move with speeds of 1 QS cm/s, or even faster. For engineering applications the instantaneous elasticity of these fluids is of little interest; the practical dynamics is governed by diffusion, ·say, by the Navier-Stokes equations. On the other hand, there are other liquids which are known to have much longer times of relaxation.
Download or read book Numerical Simulation of Particulate Two phase Flow written by Neelesh Ashok Patankar and published by . This book was released on 1997 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bubbles Drops and Particles in Non Newtonian Fluids written by R.P. Chhabra and published by CRC Press. This book was released on 2006-07-25 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bubbles, Drops, and Particles in Non-Newtonian Fluids, Second Edition continues to provide thorough coverage of the scientific foundations and the latest advances in particle motion in non-Newtonian media. The book demonstrates how dynamic behavior of single particles can yield useful information for modeling transport processes in complex multipha
Download or read book Waves in Elastic and Viscoelastic Solids written by Clifford Truesdell and published by . This book was released on 1984 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluids Materials and Microgravity written by Marcello Lappa and published by Elsevier. This book was released on 2004 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space research -- Fundamental concepts, mathematical models and scaling analysis for the microgravity environment -- Dispersed droplets and metal alloys -- Growth of semiconductors : the floating zone technique -- Macromolecular crystal growth : surface kinetics and morphological studies -- Macromolecular crystal growth at macroscopic length scales -- The growth of biological tissues.
Download or read book Advances in the Flow and Rheology of Non Newtonian Fluids written by D.A. Siginer and published by Elsevier. This book was released on 1999-05-07 with total page 895 pages. Available in PDF, EPUB and Kindle. Book excerpt: These two volumes contain chapters written by experts in such areas as bio and food rheology, polymer rheology, flow of suspensions, flow in porous media, electrorheological fluids, etc. Computational as well as analytical mathematical descriptions, involving appropriate constitutive equations deal with complex flow situations of industrial importance. This work is unique in that it brings together state of the art reviews and recent advances in a variety of areas, involving viscoelastic materials, in a desirable and timely manner.
Download or read book Mechanics of Viscoelastic Fluids written by S. Zahorski and published by Springer. This book was released on 1982-10-31 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
